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  • how to access a label form user control in Parent class ?

    - by haansi
    I have a class UserControlBase that inherits System.Web.UI.UserControl and my user controls inherit UserControlBase class. UserControlBase has some common functions that are used in all user controls. I want to put error display funtion to UserControlBase as well so that I may not have to declare and manage it in all user controls. Error will be displayed in some label in usercontrol. Issue is how to access label which is in usercontrol in UserControlBase in function ? I dont want to pass label as argument. Please guide me on this issue. thanks

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  • How can I validate input to the edit control of a cell in a DataGridView?

    - by Stuart Helwig
    It appears that the only way to capture the keypress events within a cell of a DataGridView control, in order to validate user input as they type, is to us the DataGridView controls OnEditControlShowing event, hook up a method to the edit control's (e.Control) keypress event and do some validation. My problem is that I've built a heap of custom DataGridView column classes, with their own custom cell types. These cells have their own custom edit controls (things like DateTimePickers, and Numeric or Currency textboxes.) I want to do some numeric validation for those cells that have Numeric of Currency Textboxes as their edit controls but not all the other cell types. How can I determine, within the DataGridView's "OnEditControlShowing" override, whether or not a particular edit control needs some numeric validation?

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  • specify parent window in Windows Resource Script file(*.rc)

    - by welemon
    Hi, I'm looking for a method to specify parent window in *.rc file. In *.rc file, it contains the layout and controls of a dialog. Any new control added into it, will automatically become a child window of Dialog itself. But I want to add a custom draw window into dialog, and some other controls which has that "custom draw window" as parent window, not dialog itself. I know I can use ::CreateWindow(...) API to dynamic create a window in code, and specify the custom draw window as parent HWND. But we already has child controls layout in *.rc file, I just want to reuse them, without create HWND again. Thanks, William L.

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  • c# 4.0 - best way to refactor a block of "If (something is Type) {}" statements?

    - by Andrew Johns
    I've got some code that looks like this, public void ResetControls(Control controlOnPage) { if (controlOnPage is TextBox) { ResetTextBoxControl(controlOnPage); } if (controlOnPage is MediaPicker) { ((MediaPicker)controlOnPage).Media = null; } if (controlOnPage is RelatedContentPicker) { ((RelatedContentPicker)controlOnPage).RelatedContentCollection = null; } ... ... foreach (Control child in controlOnPage.Controls) { ResetControls(child); } } The idea behind it is that I can pass a page to the method and it'll recursively reset all the controls on it to their default states - in the case of MediaPicker and RelatedContentPicker, these are user controls that I've created. FXCop warns me "Do Not Cast Unnecessarily" for this code - but I'm unsure how to rewrite it to make it better. Any ideas?

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  • UserControl that is also a Grid in WPF

    - by drasto
    I would like to create a UserControl that will have some behavior(animated collapsing...) and some Controls in it (Rectangle, Ellipse, mostly for design purposes). However I need it to be a valid Panel like Grid so I can put more controls in it when designing main window. Controls that will be add to the new USerControl in main window design time does not need to interact with components that are added to it when creating a UserControl. How should I do this ? Do I have to extends Control? I'd prefer to extend just UserControl.

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  • i try to combine GUI with class - no success

    - by Gold
    hi i made a class that make registration to my WinCE program. how i can from the class draw pannel + textbox, and catch the enter press from the textbox ? i try to do this: TextBox tb=new TextBox(); tb.Location=new Point(10,10); Panel pn=new Panel(); pn.Dock=DockStyle.Fill; pn.Controls.Add(tb); this.Controls.Add(pn); but i got error in: this.Controls.Add(pn); is there any simple sample code for this ? thank's in advance

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  • LoadViewState not fired on my user control

    - by Jeremy
    I have a user control nested in a repeater. Inside my user control I have another repeater and in that I have a panel. I am trying to override the LoadViewState event of my user control and dynamically add controls to the panel. I want to do it in the LoadViewState so that the dynamic controls get added before the viewstate gets loaded, so they retain their values after post backs. For some reason the LoadViewState event on the user control (ascx) is not firing. Is there some way to force it to fire, or is there another method I could use? I have ruled out the user controls repeater databind event, because I need it to work even if data binding isn't happening and I can't do it on the repeaters item created event either because the child panel and inner html doesn't exist yet.

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  • Specifying a unique control name when adding at runtime (like the VS IDE)

    - by user316383
    hi, I have a basic IDE for a user control i am building. It allows me to add labels to a panel and move them around, like a very basic form designer. When I add the controls to the panel at runtime, I'd like to give the control a unique name string like how the VS IDE tracks the controls it already has and adds an extra number when it creates the default control name. I have tried checking the controls collection each time a new control is added, but wasnt sure if there was a good string comparison method to return a name with a unique number on the end that hasn't been used yet.

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  • vb.net more performance for moving objects

    - by René
    I have the mission to make a small game for a school project. Pictures boxes, moved by a timer for walking enemies.If there are around 5 or 6 moving picture boxes at the form, my application get troubles and lags. After I kill some enemies (remove them from the Controls Collection of the Form/Panel) It come back smooth. I think the loop of the enemy movement is too complicated but I don't know how to make that simpler. Private Sub TimerEnemyMovement_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerEnemyMovement.Tick For Each Enemy As Control In PanelBackground.Controls If Enemy.Name.Substring(0, 5) = "Enemy" Then _enemy.MoveEnemy(Enemy, 2) End If Next End Sub I also thought about Multithreading but not sure this would solve the problem and there is also the problem that I can't access the Controls of my mainform. You see, I don't have much knowledge about vb.net Any ideas how to fix that lag?

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  • Handle CSliderCtl messages placed on a CDialogBar

    - by user173438
    VS2008, 32 Bit Win XP In a class derived from CFrameWnd, I have an object of CDialogBar that needs to have certain controls on it. Among these controls would be 2 sliders, whose event handling is to be done in CFrameWnd derived class. How shall I go about this? class CFrameWndCustom : public CFrameWnd { CDialogBar m_wndDialogBar; // the CDialogBar object. } In CFrameWnd derived class's OnCreateClient, I have created the DialogBar using the above object like: //Create the DialogBar if (!m_wndDialogBar.Create(this, IDD_DIALOGBAR_CONTROL, CBRS_BOTTOM, IDD_DIALOGBAR_CONTROL)) { TRACE("Warning: Couldn't create DialogBar Control!\n"); return FALSE; } Here, IDD_DIALOGBAR_CONTROL is a dialog resource with Style as Child. After this, I drag-dropped a CSliderCtrl on the IDD_DIALOGBAR_CONTROL in Resource View. Now, how/where should I handle the CSliderCtrl's events? There would be 2 such slider controls. I finally need the values of the sliders in CFrameWndCustom class. best regards, Divya

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  • How do I declare a C# Web User Control but stop it from initializing?

    - by Scott Stafford
    I have a C#/ASP.NET .aspx page that declares two controls that each represents the content of one tab. I want a query string argument (e.g., ?tab=1) to determine which of the two controls is activated. My problem is, they both go through the initialization events and populate their child controls, wasting CPU resources and slowing the response time. Is it possible to deactivate them somehow so they don't go through any initialization? My .aspx page looks like this: <% if (TabId == 0) { %> <my:usercontroltabone id="ctrl1" runat="server" /> <% } else if (TabId == 1) { %> <my:usercontroltabtwo id="ctrl2" runat="server" /> <% } %> And that part works fine. I assumed the that <%'s would have meant the control wouldn't actually be declared and so wouldn't initialize, but that isn't so...

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  • HTML5 video on Chrome

    - by Rob
    I'm using the following HTML5 to display video, but only the controls show up in Chrome. Works fine in Safari and Firefox: <video width="720" height="480" controls="controls" preload="preload"> <source src="<?php bloginfo('url'); ?>/wp-content/uploads/Reel.ogv" type="video/ogg; codecs=theora,vorbis" > <source src="<?php bloginfo('url'); ?>/wp-content/uploads/Reel.mp4" type="video/mp4"> Your browser doesn't support video. </video> Any ideas?

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  • Web Application Architecture (ASP.NET 3.5,JavaScript)

    - by Niv
    hey all , background - I'm using an activx that allow me to access some information on the client side, By using the activex events and callback i'm updating server side from client. i wrote a user control that register all activex's events so when one of the events occuer there is a callback to the server that handle this event. I need to write some other user controls based on this control so on every callback this user controls will be render on the client side. My question is - what is the best way to make a shared infrastructure that handle this events and render the right content base on user controls? is there any other ways i can use ? thanks!

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  • UI updates not happening in the expected order

    - by allonym
    I have a Panel which hosts a number of child controls in a grid layout. The child controls each consist of a Panel with a PictureBox and a Label. When one of these child controls is clicked it becomes "selected" (which basically entails changing its background to a different color) and an event is fired. In the handler for this event, an image is displayed in a PictureBox on a separate form. In code, the background of the child control is definitely changed before firing the event, but for some reason it never updates at runtime until after the image has updated in the other Form. I've tried to Invalidate() and Refresh() the child control before firing the event, without effect. Why is this happening, and what can I do to set it right?

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  • ASP.net PreInit() Vs Init()

    - by ASP.netBeginner
    From local forum i understood that PreInit can be used to handle the following PreInit() >Master pages can be called dynamically >Themes can be set dynamically >Programatically add controls to controls collection and i read Init() is for Init() In this event, we can read the controls properties (set at design time). We cannot read control values changed by the user because that changed value will get loaded after LoadPostData() event fires. Question I am not getting the point "We cannot read control values changed by the user".Where do users change the value of control?.Example would help me to understand the point.

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  • Best way to handle different panels occupying same area

    - by gmnnn
    I have this application: I want to change the marked area when the user is clicked one of the navBarItems (like Microsoft OUTLOOK). I've been doing some research and a lot of people said that I can add several panels and show/hide them when user is clicked a navBarItem. But the area will contain a lot of gridviews and a lot of other controls. I don't know if I want to initialize all of them when application starts because it's gonna be hard on the cpu and memory to keep all the controls running at the same time. And I don't think it's an elegant solution for this kind of situation. But if I choose to initialize controls when user is clicked to corresponding navBarItem, it's gonna be laggy for the user. What is the best design approach for this situation? PS: I can use commercial libraries too. Thank you.

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  • How to edit item in a listbox shown from reading a .csv file?

    - by Shuvo
    I am working in a project where my application can open a .csv file and read data from it. The .csv file contains the latitude, longitude of places. The application reads data from the file shows it in a static map and display icon on the right places. The application can open multiple file at a time and it opens with a new tab every time. But I am having trouble in couple of cases When I am trying to add a new point to the .csv file opened. I am able to write new point on the same file instead adding a new point data to the existing its replacing others and writing the new point only. I cannot use selectedIndexChange event to perform edit option on the listbox and then save the file. Any direction would be great. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.IO; namespace CourseworkExample { public partial class Form1 : Form { public GPSDataPoint gpsdp; List<GPSDataPoint> data; List<PictureBox> pictures; List<TabPage> tabs; public static int pn = 0; private TabPage currentComponent; private Bitmap bmp1; string[] symbols = { "hospital", "university" }; Image[] symbolImages; ListBox lb = new ListBox(); string name = ""; string path = ""; public Form1() { InitializeComponent(); data = new List<GPSDataPoint>(); pictures = new List<PictureBox>(); tabs = new List<TabPage>(); symbolImages = new Image[symbols.Length]; for (int i = 0; i < 2; i++) { string location = "data/" + symbols[i] + ".png"; symbolImages[i] = Image.FromFile(location); } } private void openToolStripMenuItem_Click(object sender, EventArgs e) { FileDialog ofd = new OpenFileDialog(); string filter = "CSV File (*.csv)|*.csv"; ofd.Filter = filter; DialogResult dr = ofd.ShowDialog(); if (dr.Equals(DialogResult.OK)) { int i = ofd.FileName.LastIndexOf("\\"); name = ofd.FileName; path = ofd.FileName; if (i > 0) { name = ofd.FileName.Substring(i + 1); path = ofd.FileName.Substring(0, i + 1); } TextReader input = new StreamReader(ofd.FileName); string mapName = input.ReadLine(); GPSDataPoint gpsD = new GPSDataPoint(); gpsD.setBounds(input.ReadLine()); string s; while ((s = input.ReadLine()) != null) { gpsD.addWaypoint(s); } input.Close(); TabPage tabPage = new TabPage(); tabPage.Location = new System.Drawing.Point(4, 22); tabPage.Name = "tabPage" + pn; lb.Width = 300; int selectedindex = lb.SelectedIndex; lb.Items.Add(mapName); lb.Items.Add("Bounds"); lb.Items.Add(gpsD.Bounds[0] + " " + gpsD.Bounds[1] + " " + gpsD.Bounds[2] + " " + gpsD.Bounds[3]); lb.Items.Add("Waypoint"); foreach (WayPoint wp in gpsD.DataList) { lb.Items.Add(wp.Name + " " + wp.Latitude + " " + wp.Longitude + " " + wp.Ele + " " + wp.Sym); } tabPage.Controls.Add(lb); pn++; tabPage.Padding = new System.Windows.Forms.Padding(3); tabPage.Size = new System.Drawing.Size(192, 74); tabPage.TabIndex = 0; tabPage.Text = name; tabPage.UseVisualStyleBackColor = true; tabs.Add(tabPage); tabControl1.Controls.Add(tabPage); tabPage = new TabPage(); tabPage.Location = new System.Drawing.Point(4, 22); tabPage.Name = "tabPage" + pn; pn++; tabPage.Padding = new System.Windows.Forms.Padding(3); tabPage.Size = new System.Drawing.Size(192, 74); tabPage.TabIndex = 0; tabPage.Text = mapName; string location = path + mapName; tabPage.UseVisualStyleBackColor = true; tabs.Add(tabPage); PictureBox pb = new PictureBox(); pb.Name = "pictureBox" + pn; pb.Image = Image.FromFile(location); tabControl2.Controls.Add(tabPage); pb.Width = pb.Image.Width; pb.Height = pb.Image.Height; tabPage.Controls.Add(pb); currentComponent = tabPage; tabPage.Width = pb.Width; tabPage.Height = pb.Height; pn++; tabControl2.Width = pb.Width; tabControl2.Height = pb.Height; bmp1 = (Bitmap)pb.Image; int lx, ly; float realWidth = gpsD.Bounds[1] - gpsD.Bounds[3]; float imageW = pb.Image.Width; float dx = imageW * (gpsD.Bounds[1] - gpsD.getWayPoint(0).Longitude) / realWidth; float realHeight = gpsD.Bounds[0] - gpsD.Bounds[2]; float imageH = pb.Image.Height; float dy = imageH * (gpsD.Bounds[0] - gpsD.getWayPoint(0).Latitude) / realHeight; lx = (int)dx; ly = (int)dy; using (Graphics g = Graphics.FromImage(bmp1)) { Rectangle rect = new Rectangle(lx, ly, 20, 20); if (gpsD.getWayPoint(0).Sym.Equals("")) { g.DrawRectangle(new Pen(Color.Red), rect); } else { if (gpsD.getWayPoint(0).Sym.Equals("hospital")) { g.DrawImage(symbolImages[0], rect); } else { if (gpsD.getWayPoint(0).Sym.Equals("university")) { g.DrawImage(symbolImages[1], rect); } } } } pb.Image = bmp1; pb.Invalidate(); } } private void openToolStripMenuItem_Click_1(object sender, EventArgs e) { FileDialog ofd = new OpenFileDialog(); string filter = "CSV File (*.csv)|*.csv"; ofd.Filter = filter; DialogResult dr = ofd.ShowDialog(); if (dr.Equals(DialogResult.OK)) { int i = ofd.FileName.LastIndexOf("\\"); name = ofd.FileName; path = ofd.FileName; if (i > 0) { name = ofd.FileName.Substring(i + 1); path = ofd.FileName.Substring(0, i + 1); } TextReader input = new StreamReader(ofd.FileName); string mapName = input.ReadLine(); GPSDataPoint gpsD = new GPSDataPoint(); gpsD.setBounds(input.ReadLine()); string s; while ((s = input.ReadLine()) != null) { gpsD.addWaypoint(s); } input.Close(); TabPage tabPage = new TabPage(); tabPage.Location = new System.Drawing.Point(4, 22); tabPage.Name = "tabPage" + pn; ListBox lb = new ListBox(); lb.Width = 300; lb.Items.Add(mapName); lb.Items.Add("Bounds"); lb.Items.Add(gpsD.Bounds[0] + " " + gpsD.Bounds[1] + " " + gpsD.Bounds[2] + " " + gpsD.Bounds[3]); lb.Items.Add("Waypoint"); foreach (WayPoint wp in gpsD.DataList) { lb.Items.Add(wp.Name + " " + wp.Latitude + " " + wp.Longitude + " " + wp.Ele + " " + wp.Sym); } tabPage.Controls.Add(lb); pn++; tabPage.Padding = new System.Windows.Forms.Padding(3); tabPage.Size = new System.Drawing.Size(192, 74); tabPage.TabIndex = 0; tabPage.Text = name; tabPage.UseVisualStyleBackColor = true; tabs.Add(tabPage); tabControl1.Controls.Add(tabPage); tabPage = new TabPage(); tabPage.Location = new System.Drawing.Point(4, 22); tabPage.Name = "tabPage" + pn; pn++; tabPage.Padding = new System.Windows.Forms.Padding(3); tabPage.Size = new System.Drawing.Size(192, 74); tabPage.TabIndex = 0; tabPage.Text = mapName; string location = path + mapName; tabPage.UseVisualStyleBackColor = true; tabs.Add(tabPage); PictureBox pb = new PictureBox(); pb.Name = "pictureBox" + pn; pb.Image = Image.FromFile(location); tabControl2.Controls.Add(tabPage); pb.Width = pb.Image.Width; pb.Height = pb.Image.Height; tabPage.Controls.Add(pb); currentComponent = tabPage; tabPage.Width = pb.Width; tabPage.Height = pb.Height; pn++; tabControl2.Width = pb.Width; tabControl2.Height = pb.Height; bmp1 = (Bitmap)pb.Image; int lx, ly; float realWidth = gpsD.Bounds[1] - gpsD.Bounds[3]; float imageW = pb.Image.Width; float dx = imageW * (gpsD.Bounds[1] - gpsD.getWayPoint(0).Longitude) / realWidth; float realHeight = gpsD.Bounds[0] - gpsD.Bounds[2]; float imageH = pb.Image.Height; float dy = imageH * (gpsD.Bounds[0] - gpsD.getWayPoint(0).Latitude) / realHeight; lx = (int)dx; ly = (int)dy; using (Graphics g = Graphics.FromImage(bmp1)) { Rectangle rect = new Rectangle(lx, ly, 20, 20); if (gpsD.getWayPoint(0).Sym.Equals("")) { g.DrawRectangle(new Pen(Color.Red), rect); } else { if (gpsD.getWayPoint(0).Sym.Equals("hospital")) { g.DrawImage(symbolImages[0], rect); } else { if (gpsD.getWayPoint(0).Sym.Equals("university")) { g.DrawImage(symbolImages[1], rect); } } } } pb.Image = bmp1; pb.Invalidate(); MessageBox.Show(data.ToString()); } } private void exitToolStripMenuItem_Click(object sender, EventArgs e) { this.Close(); } private void addBtn_Click(object sender, EventArgs e) { string wayName = nameTxtBox.Text; float wayLat = Convert.ToSingle(latTxtBox.Text); float wayLong = Convert.ToSingle(longTxtBox.Text); float wayEle = Convert.ToSingle(elevTxtBox.Text); WayPoint wp = new WayPoint(wayName, wayLat, wayLong, wayEle); GPSDataPoint gdp = new GPSDataPoint(); data = new List<GPSDataPoint>(); gdp.Add(wp); lb.Items.Add(wp.Name + " " + wp.Latitude + " " + wp.Longitude + " " + wp.Ele + " " + wp.Sym); lb.Refresh(); StreamWriter sr = new StreamWriter(name); sr.Write(lb); sr.Close(); DialogResult result = MessageBox.Show("Save in New File?","Save", MessageBoxButtons.YesNo); if (result == DialogResult.Yes) { SaveFileDialog saveDialog = new SaveFileDialog(); saveDialog.FileName = "default.csv"; DialogResult saveResult = saveDialog.ShowDialog(); if (saveResult == DialogResult.OK) { sr = new StreamWriter(saveDialog.FileName, true); sr.WriteLine(wayName + "," + wayLat + "," + wayLong + "," + wayEle); sr.Close(); } } else { // sr = new StreamWriter(name, true); // sr.WriteLine(wayName + "," + wayLat + "," + wayLong + "," + wayEle); sr.Close(); } MessageBox.Show(name + path); } } } GPSDataPoint.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; namespace CourseworkExample { public class GPSDataPoint { private float[] bounds; private List<WayPoint> dataList; public GPSDataPoint() { dataList = new List<WayPoint>(); } internal void setBounds(string p) { string[] b = p.Split(','); bounds = new float[b.Length]; for (int i = 0; i < b.Length; i++) { bounds[i] = Convert.ToSingle(b[i]); } } public float[] Bounds { get { return bounds; } } internal void addWaypoint(string s) { WayPoint wp = new WayPoint(s); dataList.Add(wp); } public WayPoint getWayPoint(int i) { if (i < dataList.Count) { return dataList[i]; } else return null; } public List<WayPoint> DataList { get { return dataList; } } internal void Add(WayPoint wp) { dataList.Add(wp); } } } WayPoint.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace CourseworkExample { public class WayPoint { private string name; private float ele; private float latitude; private float longitude; private string sym; public WayPoint(string name, float latitude, float longitude, float elevation) { this.name = name; this.latitude = latitude; this.longitude = longitude; this.ele = elevation; } public WayPoint() { name = "no name"; ele = 3.5F; latitude = 3.5F; longitude = 0.0F; sym = "no symbol"; } public WayPoint(string s) { string[] bits = s.Split(','); name = bits[0]; longitude = Convert.ToSingle(bits[2]); latitude = Convert.ToSingle(bits[1]); if (bits.Length > 4) sym = bits[4]; else sym = ""; try { ele = Convert.ToSingle(bits[3]); } catch (Exception e) { ele = 0.0f; } } public float Longitude { get { return longitude; } set { longitude = value; } } public float Latitude { get { return latitude; } set { latitude = value; } } public float Ele { get { return ele; } set { ele = value; } } public string Name { get { return name; } set { name = value; } } public string Sym { get { return sym; } set { sym = value; } } } } .csv file data birthplace.png 51.483788,-0.351906,51.460745,-0.302982 Born Here,51.473805,-0.32532,-,hospital Danced here,51,483805,-0.32532,-,hospital

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  • How to bind a XPO Data Source to an ASPxGridView control

    - by nikolaosk
    I have been involved with an ASP.Net project recently and I have implemented it using the awesome DevExpress ASP.Net controls. In this post I will show you how to bind an XPODataSource control to an ASPxGridView control. If you want to implement this example you need to download the trial version of these controls unless you are a licensed holder of DevExpress products. We will need a database to work with. I will use AdventureWorks2008R2 . You can download it here . We will need an instance of SQL...(read more)

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  • Upgrade existing WinForms applications to use the latest RadControls

    Upgrading projects to new versions can be a pain, especially when you have to update several assemblies from a single version, as is the case with RadControls for WinForms. Q1 2010 simplifies this process a lot, by giving a couple of ways (one new and one updated) to upgrade existing applications to the latest and greatest version of RadControls for WinForms: By using the new Visual Studio Extensions (VSX), available in VS2005, VS2008 and VS2010 RC; By using the updated Project Upgrade Utility. Here are the steps: Upgrading a classic Windows Forms application to the latest RadControls for WinForms by using the Visual Studio Extensions Install RadControls for WinForms Q1 2010 Open the classic Windows Forms application (VB or C#) Open the Telerik Menu and select RadControls for WinForms --> Convert to Telerik WinForms Application     Select the Telerik controls you plan to use in the application, as well as a theme, and click OK. The VSX package will add the needed assemblies to your project automatically for you.     Replace the standard controls on your form with the respective Telerik controls.     Run the application to see the result. Upgrading an older RadControls application to the latest RadControls for WinForms by using the Visual Studio Extensions Install RadControls for WinForms Q1 2010. Open your current RadControls application (VB or C#), which uses pre-Q1 2010 assembly versions. Open the Telerik Menu and select RadControls for WinForms --> Upgrade Wizard   Choose to either use the online downloader of the latest version, or to use the currently installed version. The VSX package will check what assemblies you use in your project and will upgrade them automatically.     Run the application to see the result. Upgrading an older RadControls application to the latest RadControls for WinForms by using the Project Upgrade Utility The Q1 2010 Project Upgrade Utility now features upgrading not only a single project, but all projects in a directory/solution (recursively). The tool is quite intuitive - simply choose your solution folder (or a folder with several projects)m and click Update. Feel free to leave a comment. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Ruby Drag-n-Drop IDE and Ruby programming related

    - by RPK
    I am writing a small desktop GUI application using Ruby and Gtk2. I am using RubyMine 3 on Linux (Fedora). I created a simple class to create a Gtk Window but now I feel it takes more time to just keep adding code for a Button, Drop Down and TextBox etc. I need to write even more code if the DropDown needs to be populated at run-time. Is there any Ruby Gtk IDE which supports adding Controls with simple drag-n-drop? At least I can focus on the business logic instead of just defining position and sizes of controls. One more question. I subscribed to Ruby-Forum mailing list but it is often flooded with Spam. Which is the official Ruby forum? Recently NetBeans has withdrawn support for Ruby. Is it worth to learn Ruby seriously and use it in commercial environment or not?

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  • WPF - How can I place a usercontrol over an AdornedElementPlaceholder?

    - by Kevin
    I'm trying to get the validation to not show through my custom modal dialog. I've tried setting the zindex of the dialog and and of the elements in this template. Any ideas? This is coming from a validation template: <ControlTemplate x:Key="ValidationTemplate"> <DockPanel> <TextBlock Foreground="Red" FontSize="20" Panel.ZIndex="-10">!</TextBlock> <Border Name="validationBorder" BorderBrush="Red" BorderThickness="2" Padding="1" CornerRadius="3" Panel.ZIndex="-10"> <Border.Resources> <Storyboard x:Key="_blink"> <ColorAnimationUsingKeyFrames AutoReverse="True" BeginTime="00:00:00" Storyboard.TargetName="validationBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" RepeatBehavior="Forever"> <SplineColorKeyFrame KeyTime="00:00:1" Value="#00FF0000"/> </ColorAnimationUsingKeyFrames> </Storyboard> </Border.Resources> <Border.Triggers> <EventTrigger RoutedEvent="FrameworkElement.Loaded"> <BeginStoryboard Storyboard="{StaticResource _blink}" /> </EventTrigger> </Border.Triggers> <AdornedElementPlaceholder/> </Border> </DockPanel> </ControlTemplate> The dialog: <UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" x:Class="GunMiser.Controls.PendingChangesConfirmationDialog" Height="768" Width="1024" mc:Ignorable="d"> <Grid Background="White"> <Rectangle x:Name="MainRectangle" Margin="0,0,0,0" Style="{DynamicResource UserControlOverlayRectangleStyle}" Opacity="0.85"/> <Border Margin="288,250,278,288" Background="#FF868686" BorderBrush="Black" BorderThickness="1"> <Border.Effect> <DropShadowEffect Color="#FFB6B2B2"/> </Border.Effect> <TextBlock x:Name="textBlockMessage" Margin="7,29,7,97" TextWrapping="Wrap" d:LayoutOverrides="VerticalAlignment" TextAlignment="Center"/> </Border> <Button x:Name="OkButton" Click="OkButton_Click" Margin="313,0,0,328" VerticalAlignment="Bottom" Height="24" Content="Save Changes" Style="{DynamicResource GunMiserButtonStyle}" HorizontalAlignment="Left" Width="103"/> <Button Click="CancelButton_Click" Margin="453.294,0,456,328" VerticalAlignment="Bottom" Height="24" Content="Cancel Changes" Style="{DynamicResource GunMiserButtonStyle}"/> <Button Click="CancelActionButton_Click" Margin="0,0,304,328" VerticalAlignment="Bottom" Height="24" Content="Go Back" Style="{DynamicResource GunMiserButtonStyle}" HorizontalAlignment="Right" Width="114.706"/> </Grid> </UserControl> And the overall window is: <Window x:Class="GunMiser.Views.Shell" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:cal="http://www.codeplex.com/CompositeWPF" xmlns:controls="clr-namespace:GunMiser.Controls;assembly=GunMiser.Controls" Title="Gun Miser" Height="768" Width="1024"> <Canvas> <controls:PendingChangesConfirmationDialog x:Name="PendingChangesConfirmationDialog" HorizontalAlignment="Stretch" Margin="0,0,0,0" VerticalAlignment="Stretch" Width="1008" Height="730" Visibility="Collapsed" Panel.ZIndex="100" /> <ContentControl x:Name="FilterRegion" cal:RegionManager.RegionName="FilterRegion" Width="326" Height="656" Canvas.Top="32" VerticalAlignment="Top" HorizontalAlignment="Left" /> <ContentControl Name="WorkspaceRegion" cal:RegionManager.RegionName="WorkspaceRegion" Width="678" Height="726" Canvas.Left="330" VerticalAlignment="Top" HorizontalAlignment="Left"/> <Button Click="GunsButton_Click" Width="75" Height="25" Content="Guns" Canvas.Top="3" Style="{DynamicResource GunMiserButtonStyle}"/> <Button Click="OpticsButton_Click" Width="75" Height="25" Content="Optics" Canvas.Left="81" Canvas.Top="3" Style="{DynamicResource GunMiserButtonStyle}"/> <Button Click="SettingsButton_Click" Width="56" Height="28" Content="Settings" Canvas.Left="944" Style="{DynamicResource GunMiserButtonStyle}" HorizontalAlignment="Left" VerticalAlignment="Top"/> <Button Click="AccessoriesButton_Click" Width="75" Height="25" Content="Accessories" Canvas.Left="239" Canvas.Top="3" Style="{DynamicResource GunMiserButtonStyle}"/> <Button Click="AmmunitionButton_Click" Width="75" Height="25" Content="Ammunition" Canvas.Left="160" Canvas.Top="3" Style="{DynamicResource GunMiserButtonStyle}"/> </Canvas> </Window>

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  • May 2011 Release of the Ajax Control Toolkit

    - by Stephen Walther
    I’m happy to announce that the Superexpert team has published the May 2011 release of the Ajax Control Toolkit at CodePlex. You can download the new release at the following URL: http://ajaxcontroltoolkit.codeplex.com/releases/view/65800 This release focused on improving the ModalPopup and AsyncFileUpload controls. Our team closed a total of 34 bugs related to the ModalPopup and AsyncFileUpload controls. Enhanced ModalPopup Control You can take advantage of the Ajax Control Toolkit ModalPopup control to easily create popup dialogs in your ASP.NET Web Forms applications. When the dialog appears, you cannot interact with any page content which appears behind the modal dialog. For example, the following page contains a standard ASP.NET Button and Panel. When you click the Button, the Panel appears as a popup dialog: <%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Simple.aspx.vb" Inherits="ACTSamples.Simple" %> <%@ Register TagPrefix="act" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Simple Modal Popup Sample</title> <style type="text/css"> html { background-color: blue; } #dialog { border: 2px solid black; width: 500px; background-color: White; } #dialogContents { padding: 10px; } .modalBackground { background-color:Gray; filter:alpha(opacity=70); opacity:0.7; } </style> </head> <body> <form id="form1" runat="server"> <div> <act:ToolkitScriptManager ID="tsm" runat="server" /> <asp:Panel ID="dialog" runat="server"> <div id="dialogContents"> Here are the contents of the dialog. <br /> <asp:Button ID="btnOK" Text="OK" runat="server" /> </div> </asp:Panel> <asp:Button ID="btnShow" Text="Open Dialog" runat="server" /> <act:ModalPopupExtender TargetControlID="btnShow" PopupControlID="dialog" OkControlID="btnOK" DropShadow="true" BackgroundCssClass="modalBackground" runat="server" /> </div> </form> </body> </html>     Notice that the page includes two controls from the Ajax Control Toolkit: the ToolkitScriptManager and the ModalPopupExtender control. Any page which uses any of the controls from the Ajax Control Toolkit must include a ToolkitScriptManager. The ModalPopupExtender is used to create the popup. The following properties are set: · TargetControlID – This is the ID of the Button or LinkButton control which causes the modal popup to be displayed. · PopupControlID – This is the ID of the Panel control which contains the content displayed in the modal popup. · OKControlID – This is the ID of a Button or LinkButton which causes the modal popup to close. · DropShadow – Displays a drop shadow behind the modal popup. · BackgroundCSSClass – The name of a Cascading Style Sheet class which is used to gray out the background of the page when the modal popup is displayed. The ModalPopup is completely cross-browser compatible. For example, the following screenshots show the same page displayed in Firefox 4, Internet Explorer 9, and Chrome 11: The ModalPopup control has lots of nice properties. For example, you can make the ModalPopup draggable. You also can programmatically hide and show a modal popup from either server-side or client-side code. To learn more about the properties of the ModalPopup control, see the following website: http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/ModalPopup/ModalPopup.aspx Animated ModalPopup Control In the May 2011 release of the Ajax Control Toolkit, we enhanced the Modal Popup control so that it supports animations. We made this modification in response to a feature request posted at CodePlex which got 65 votes (plenty of people wanted this feature): http://ajaxcontroltoolkit.codeplex.com/workitem/6944 I want to thank Dani Kenan for posting a patch to this issue which we used as the basis for adding animation support for the modal popup. Thanks Dani! The enhanced ModalPopup in the May 2011 release of the Ajax Control Toolkit supports the following animations: OnShowing – Called before the modal popup is shown. OnShown – Called after the modal popup is shown. OnHiding – Called before the modal popup is hidden. OnHidden – Called after the modal popup is hidden. You can use these animations, for example, to fade-in a modal popup when it is displayed and fade-out the popup when it is hidden. Here’s the code: <act:ModalPopupExtender ID="ModalPopupExtender1" TargetControlID="btnShow" PopupControlID="dialog" OkControlID="btnOK" DropShadow="true" BackgroundCssClass="modalBackground" runat="server"> <Animations> <OnShown> <Fadein /> </OnShown> <OnHiding> <Fadeout /> </OnHiding> </Animations> </act:ModalPopupExtender>     So that you can experience the full joy of this animated modal popup, I recorded the following video: Of course, you can use any of the animations supported by the Ajax Control Toolkit with the modal popup. The animation reference is located here: http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/Walkthrough/AnimationReference.aspx Fixes to the AsyncFileUpload In the May 2011 release, we also focused our energies on performing bug fixes for the AsyncFileUpload control. We fixed several major issues with the AsyncFileUpload including: It did not work in master pages It did not work when ClientIDMode=”Static” It did not work with Firefox 4 It did not work when multiple AsyncFileUploads were included in the same page It generated markup which was not HTML5 compatible The AsyncFileUpload control is a super useful control. It enables you to upload files in a form without performing a postback. Here’s some sample code which demonstrates how you can use the AsyncFileUpload: <%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Simple.aspx.vb" Inherits="ACTSamples.Simple1" %> <%@ Register TagPrefix="act" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> <title>Simple AsyncFileUpload</title> </head> <body> <form id="form1" runat="server"> <div> <act:ToolkitScriptManager ID="tsm" runat="server" /> User Name: <br /> <asp:TextBox ID="txtUserName" runat="server" /> <asp:RequiredFieldValidator EnableClientScript="false" ErrorMessage="Required" ControlToValidate="txtUserName" runat="server" /> <br /><br /> Avatar: <act:AsyncFileUpload ID="async1" ThrobberID="throbber" UploadingBackColor="yellow" ErrorBackColor="red" CompleteBackColor="green" UploaderStyle="Modern" PersistFile="true" runat="server" /> <asp:Image ID="throbber" ImageUrl="uploading.gif" style="display:none" runat="server" /> <br /><br /> <asp:Button ID="btnSubmit" Text="Submit" runat="server" /> </div> </form> </body> </html> And here’s the code-behind for the page above: Public Class Simple1 Inherits System.Web.UI.Page Private Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click If Page.IsValid Then ' Get Form Fields Dim userName As String Dim file As Byte() userName = txtUserName.Text If async1.HasFile Then file = async1.FileBytes End If ' Save userName, file to database ' Redirect to success page Response.Redirect("SimpleDone.aspx") End If End Sub End Class   The form above contains an AsyncFileUpload which has values for the following properties: ThrobberID – The ID of an element in the page to display while a file is being uploaded. UploadingBackColor – The color to display in the upload field while a file is being uploaded. ErrorBackColor – The color to display in the upload field when there is an error uploading a file. CompleteBackColor – The color to display in the upload field when the upload is complete. UploaderStyle – The user interface style: Traditional or Modern. PersistFile – When true, the uploaded file is persisted in Session state. The last property PersistFile, causes the uploaded file to be stored in Session state. That way, if completing a form requires multiple postbacks, then the user needs to upload the file only once. For example, if there is a server validation error, then the user is not required to re-upload the file after fixing the validation issue. In the sample code above, this condition is simulated by disabling client-side validation for the RequiredFieldValidator control. The RequiredFieldValidator EnableClientScript property has the value false. The following video demonstrates how the AsyncFileUpload control works: You can learn more about the properties and methods of the AsyncFileUpload control by visiting the following page: http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/AsyncFileUpload/AsyncFileUpload.aspx Conclusion In the May 2011 release of the Ajax Control Toolkit, we addressed over 30 bugs related to the ModalPopup and AsyncFileUpload controls. Furthermore, by building on code submitted by the community, we enhanced the ModalPopup control so that it supports animation (Thanks Dani). In our next sprint for the June release of the Ajax Control Toolkit, we plan to focus on the HTML Editor control. Subscribe to this blog to keep updated.

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  • Welcome to my geeks blog

    - by bconlon
    Hi and welcome! I'm Bazza and this is my geeks blog. I have 20 years Visual Studio mainly C++, MFC,  ATL and now, thankfully, C# and I am embarking on the new world (well new to me) of WPF, so I thought I would try and capture my successful...and not so successful...WPF experiences with the geek world. So where to start? WPF? What I know so far... From wiki..."Windows Presentation Foundation (or WPF) is a graphical subsystem for rendering user interfaces in Windows-based applications." Hmm, great but didn't MFC, ATL (my head hurt with that one), and .Net all have APIs to allow me to code against the Windows Graphical Device Interface (GDI)? "Rather than relying on the older GDI subsystem, WPF utilizes DirectX. WPF attempts to provide a consistent programming model for building applications and provides a separation between the user interface and the business logic." OK, different drawing code, same Windows and weren't we always taught to separate our UI, Business Layer and Data Access Layer? "WPF employs XAML, a derivative of XML, to define and link various UI elements. WPF applications can be deployed as standalone desktop programs, or hosted as an embedded object in a website." Cool, now we're getting somewhere. So when they say separation they really mean separation. The crux of this appears to be that you can have creative people writing the UI and making it attractive and intuitive to use, whist the geeks concentrate on writing the Business and Data Access stuff. XAML (eXtensible Application Markup Language) maps XML elements and attributes directly to Common Language Runtime (CLR) object instances, properties and events. True separation of the View and Model. WPF also provides logical separation of a control from its appearance. In a traditional Windows system, all Controls have a base class containing a Windows handle and each Control knows how to render itself. In WPF, the controls are more like those in a Web Browser using Cascading Style Sheet, they are not wrappers for standard Windows Controls. Instead, they have a default 'template' that defines a visual theme which can easily be replaced by a custom template. But it gets better. WPF concentrates heavily on Data Binding where the client can bind directly to data on the server. I think this concept was first introduced in 'Classic' Visual Basic, where you could bind a list directly to a data from an Access database, and you could do similar in ASP .Net. However, the WPF implementation is far superior than it's predecessors. There are also other technologies that I want to look at like LINQ and the Entity Framework, but that's all for now. #

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  • JavaScript Intellisense with Telerik in ASP.NET Master Page Project with VS 2010

    - by Otto Neff
    Today I was looking for a solution to get finally the JScript/Javascript/jQuery Intellisense Featureworking with my ASP.Net Webform Project to work. I found some good articles: - JScript IntelliSense Overview- JScript IntelliSense: A Reference for the “Reference” Tag- Enabling JavaScript intellisense in VS.NET 2010 to work with SharePoint 2010- Rich IntelliSense for jQueryBUT, all of suggested solutions did not work right with my Master Page based Visual Studio 2010 Solution.Only with physical Javascript Files (Telerik includes certain Javascript Files like jQuery as Ressource) or/andconfigure always a new ASP.NET Scriptmanager / RadScriptManager on every page derived from the Master Page, wasn't exactly what I was looking for. So I came up with the following simple Solution, to Trick VS2010and still have the Project running with multiple runat="server" Scriptmanagers. In short:- New ASP.NET control derived from ScriptManager with emtpy overwritten OnInit() to use it as emtpy wrapper for VS2010. In detail:New RadScriptManager Classusing System; using System.Collections.Generic; using System.Linq; using System.Web; using Telerik.Web.UI; namespace IntellisenseJavascript.Controls { public class IntelliJS : RadScriptManager { protected override void OnInit(EventArgs e) { } protected override void OnPreRender(EventArgs e) { } protected override void OnLoad(EventArgs e) { } protected override void Render(System.Web.UI.HtmlTextWriter writer) { } public override void RenderControl(System.Web.UI.HtmlTextWriter writer) { } } } web.config<configuration> ... <system.web> ... <pages> <controls> <add tagPrefix="telerik" namespace="Telerik.Web.UI" assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4"/> <add tagPrefix="VSFix" namespace="IntellisenseJavascript.Controls" assembly="IntellisenseJavascript"/> </controls> </pages> ... Master Page<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site.master.cs" Inherits="IntellisenseJavascript.Site" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html > <head id="head" runat="server"> <title></title> <telerik:RadStyleSheetManager ID="radStyleSheetManager" runat="server" /> </head> <body> <form id="form" runat="server"> <telerik:RadScriptManager ID="radScriptManager" runat="server"> <Scripts> <asp:ScriptReference Assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4" Name="Telerik.Web.UI.Common.Core.js" /> <asp:ScriptReference Assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4" Name="Telerik.Web.UI.Common.jQuery.js" /> <asp:ScriptReference Assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4" Name="Telerik.Web.UI.Common.jQueryInclude.js" /> </Scripts> </telerik:RadScriptManager> <telerik:RadAjaxManager ID="radAjaxManager" runat="server"> </telerik:RadAjaxManager> <div> #MASTER CONTENT# <asp:ContentPlaceHolder ID="contentPlaceHolder" runat="server"> </asp:ContentPlaceHolder> </div> </form> <script type="text/javascript"> $(function () { // Masterpage ready $('body').css('margin', '50px'); }); </script> </body> </html> ASPX Page<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="IntellisenseJavascript.Default" %> <asp:Content ID="Content1" ContentPlaceHolderID="contentPlaceHolder" runat="server"> <VSFix:IntelliJS runat="server" ID="intelliJS"> <Scripts> <asp:ScriptReference Assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4" Name="Telerik.Web.UI.Common.Core.js" /> <asp:ScriptReference Assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4" Name="Telerik.Web.UI.Common.jQuery.js" /> <asp:ScriptReference Assembly="Telerik.Web.UI, Version=2011.3.1115.40, Culture=neutral, PublicKeyToken=121fae78165ba3d4" Name="Telerik.Web.UI.Common.jQueryInclude.js" /> </Scripts> </VSFix:IntelliJS> <div style="border: 5px solid #FF9900;"> #PAGE CONTENT# </div> <script type="text/javascript"> $(function () { // Page ready $('body').css('border', '5px solid #888'); }); </script> </asp:Content> The Result I know, this is not the way it meant to be... but now at least you can have a Main ScriptManager for all Common Scripts and Settings, inject page specific Javascripts in PageLoad Event in normal ASPX Files and have JavaScript Intellisense for defined Scripts from JS Files or Assembly Ressouce in your Content Maybe, vNext will fix this.

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  • Demystifying Silverlight Dependency Properties

    - by dwahlin
    I have the opportunity to teach a lot of people about Silverlight (amongst other technologies) and one of the topics that definitely confuses people initially is the concept of dependency properties. I confess that when I first heard about them my initial thought was “Why do we need a specialized type of property?” While you can certainly use standard CLR properties in Silverlight applications, Silverlight relies heavily on dependency properties for just about everything it does behind the scenes. In fact, dependency properties are an essential part of the data binding, template, style and animation functionality available in Silverlight. They simply back standard CLR properties. In this post I wanted to put together a (hopefully) simple explanation of dependency properties and why you should care about them if you’re currently working with Silverlight or looking to move to it.   What are Dependency Properties? XAML provides a great way to define layout controls, user input controls, shapes, colors and data binding expressions in a declarative manner. There’s a lot that goes on behind the scenes in order to make XAML work and an important part of that magic is the use of dependency properties. If you want to bind data to a property, style it, animate it or transform it in XAML then the property involved has to be a dependency property to work properly. If you’ve ever positioned a control in a Canvas using Canvas.Left or placed a control in a specific Grid row using Grid.Row then you’ve used an attached property which is a specialized type of dependency property. Dependency properties play a key role in XAML and the overall Silverlight framework. Any property that you bind, style, template, animate or transform must be a dependency property in Silverlight applications. You can programmatically bind values to controls and work with standard CLR properties, but if you want to use the built-in binding expressions available in XAML (one of my favorite features) or the Binding class available through code then dependency properties are a necessity. Dependency properties aren’t needed in every situation, but if you want to customize your application very much you’ll eventually end up needing them. For example, if you create a custom user control and want to expose a property that consumers can use to change the background color, you have to define it as a dependency property if you want bindings, styles and other features to be available for use. Now that the overall purpose of dependency properties has been discussed let’s take a look at how you can create them. Creating Dependency Properties When .NET first came out you had to write backing fields for each property that you defined as shown next: Brush _ScheduleBackground; public Brush ScheduleBackground { get { return _ScheduleBackground; } set { _ScheduleBackground = value; } } Although .NET 2.0 added auto-implemented properties (for example: public Brush ScheduleBackground { get; set; }) where the compiler would automatically generate the backing field used by get and set blocks, the concept is still the same as shown in the above code; a property acts as a wrapper around a field. Silverlight dependency properties replace the _ScheduleBackground field shown in the previous code and act as the backing store for a standard CLR property. The following code shows an example of defining a dependency property named ScheduleBackgroundProperty: public static readonly DependencyProperty ScheduleBackgroundProperty = DependencyProperty.Register("ScheduleBackground", typeof(Brush), typeof(Scheduler), null);   Looking through the code the first thing that may stand out is that the definition for ScheduleBackgroundProperty is marked as static and readonly and that the property appears to be of type DependencyProperty. This is a standard pattern that you’ll use when working with dependency properties. You’ll also notice that the property explicitly adds the word “Property” to the name which is another standard you’ll see followed. In addition to defining the property, the code also makes a call to the static DependencyProperty.Register method and passes the name of the property to register (ScheduleBackground in this case) as a string. The type of the property, the type of the class that owns the property and a null value (more on the null value later) are also passed. In this example a class named Scheduler acts as the owner. The code handles registering the property as a dependency property with the call to Register(), but there’s a little more work that has to be done to allow a value to be assigned to and retrieved from the dependency property. The following code shows the complete code that you’ll typically use when creating a dependency property. You can find code snippets that greatly simplify the process of creating dependency properties out on the web. The MVVM Light download available from http://mvvmlight.codeplex.com comes with built-in dependency properties snippets as well. public static readonly DependencyProperty ScheduleBackgroundProperty = DependencyProperty.Register("ScheduleBackground", typeof(Brush), typeof(Scheduler), null); public Brush ScheduleBackground { get { return (Brush)GetValue(ScheduleBackgroundProperty); } set { SetValue(ScheduleBackgroundProperty, value); } } The standard CLR property code shown above should look familiar since it simply wraps the dependency property. However, you’ll notice that the get and set blocks call GetValue and SetValue methods respectively to perform the appropriate operation on the dependency property. GetValue and SetValue are members of the DependencyObject class which is another key component of the Silverlight framework. Silverlight controls and classes (TextBox, UserControl, CompositeTransform, DataGrid, etc.) ultimately derive from DependencyObject in their inheritance hierarchy so that they can support dependency properties. Dependency properties defined in Silverlight controls and other classes tend to follow the pattern of registering the property by calling Register() and then wrapping the dependency property in a standard CLR property (as shown above). They have a standard property that wraps a registered dependency property and allows a value to be assigned and retrieved. If you need to expose a new property on a custom control that supports data binding expressions in XAML then you’ll follow this same pattern. Dependency properties are extremely useful once you understand why they’re needed and how they’re defined. Detecting Changes and Setting Defaults When working with dependency properties there will be times when you want to assign a default value or detect when a property changes so that you can keep the user interface in-sync with the property value. Silverlight’s DependencyProperty.Register() method provides a fourth parameter that accepts a PropertyMetadata object instance. PropertyMetadata can be used to hook a callback method to a dependency property. The callback method is called when the property value changes. PropertyMetadata can also be used to assign a default value to the dependency property. By assigning a value of null for the final parameter passed to Register() you’re telling the property that you don’t care about any changes and don’t have a default value to apply. Here are the different constructor overloads available on the PropertyMetadata class: PropertyMetadata Constructor Overload Description PropertyMetadata(Object) Used to assign a default value to a dependency property. PropertyMetadata(PropertyChangedCallback) Used to assign a property changed callback method. PropertyMetadata(Object, PropertyChangedCalback) Used to assign a default property value and a property changed callback.   There are many situations where you need to know when a dependency property changes or where you want to apply a default. Performing either task is easily accomplished by creating a new instance of the PropertyMetadata class and passing the appropriate values to its constructor. The following code shows an enhanced version of the initial dependency property code shown earlier that demonstrates these concepts: public Brush ScheduleBackground { get { return (Brush)GetValue(ScheduleBackgroundProperty); } set { SetValue(ScheduleBackgroundProperty, value); } } public static readonly DependencyProperty ScheduleBackgroundProperty = DependencyProperty.Register("ScheduleBackground", typeof(Brush), typeof(Scheduler), new PropertyMetadata(new SolidColorBrush(Colors.LightGray), ScheduleBackgroundChanged)); private static void ScheduleBackgroundChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { var scheduler = d as Scheduler; scheduler.Background = e.NewValue as Brush; } The code wires ScheduleBackgroundProperty to a property change callback method named ScheduleBackgroundChanged. What’s interesting is that this callback method is static (as is the dependency property) so it gets passed the instance of the object that owns the property that has changed (otherwise we wouldn’t be able to get to the object instance). In this example the dependency object is cast to a Scheduler object and its Background property is assigned to the new value of the dependency property. The code also handles assigning a default value of LightGray to the dependency property by creating a new instance of a SolidColorBrush. To Sum Up In this post you’ve seen the role of dependency properties and how they can be defined in code. They play a big role in XAML and the overall Silverlight framework. You can think of dependency properties as being replacements for fields that you’d normally use with standard CLR properties. In addition to a discussion on how dependency properties are created, you also saw how to use the PropertyMetadata class to define default dependency property values and hook a dependency property to a callback method. The most important thing to understand with dependency properties (especially if you’re new to Silverlight) is that they’re needed if you want a property to support data binding, animations, transformations and styles properly. Any time you create a property on a custom control or user control that has these types of requirements you’ll want to pick a dependency property over of a standard CLR property with a backing field. There’s more that can be covered with dependency properties including a related property called an attached property….more to come.

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