Search Results

Search found 784 results on 32 pages for 'cody gray'.

Page 15/32 | < Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >

  • plot matrix missing points in different color using gnuplot

    - by kitt
    I have a file 'matrix.dat': 1 2 3 4 5 5 - 3 4 5 - 4 5 B - 1 B 2 B 3 - 3 2 - 3 I want to plot numbers using palette, '-' using white color and 'B' using black color. In gnuplot, I use this palette (blue - cyan - green - orange - red): set palette model HSV functions 0.666*(1-gray), 1, 1 And set '-' as missing data: set datafile missing "-" plot 'matrix.dat' matrix with image Now I can only plot numbers and '-' in correct colors.

    Read the article

  • Simple 2 column CSS layout with nested divs

    - by Dan
    Hello, I have good familiarity with CSS but for some reason I am unable to achieve the result I want in this case. Here is the link to my test site http://danberinger.com/test.html Keep in mind that I want a 2 column layout and that the background wrapper color (gray) is not showing. Instead the body background color image is being put in place of where the wrapper background should be. Any suggestions would be greatly appreciated.

    Read the article

  • How to recreate the UITabBarItem image filter?

    - by boliva
    Hi, I'm writing a custom UITabBar replacement, and I would like to know how to recreate the filter that the built-in implementation does with the UITabBarItem image - that blue shining on selected tabs and gray gradient on unselected ones. I guess it's a matter of using the source image alpha value as a mask and overlay it with a pre-made blue (or whatever color) shining image and another one grayed out, but I would like to know what is the best approach from a code point of view. Best,

    Read the article

  • How to adjust padding in xaml label

    - by Bjarne
    How can I make the top and bottom padding smaller in the following label? As I see it, the bounding box in much bigger than it needs to be, but the padding is set to 0, so it cannot be any smaller. <Label Background="AliceBlue" Content="1800" FontSize="170" FontWeight="Bold" Foreground="Gray" Padding="0" />

    Read the article

  • Fetching gtk theme background color

    - by Nicola Leoni
    Hi there, I'm almost a gtk newbie, and I'm looking for a way to get the background color for the current theme in gtk. So this code: GdkColor color = gtk_widget_get_style(mainWindowHandle)->bg[GTK_STATE_NORMAL]; works only after the main window is shown, before returns an strange ugly gray.

    Read the article

  • Changing background color on UIScrollView?

    - by Andreas Johannessen
    Hi How do I change the black/gray color to white? This is just a simple view with a UIView attached to the UIViewControllers property together a with a webview that fills the UIView. UPDATE Here's the code that works: - (void)loadView { UIWebView *webview = [[UIWebView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 416.0f)]; [webView setBackgroundColor:[UIColor whiteColor]]; self.view = webView; [webview release]; } Thanks in advance.

    Read the article

  • Progress bar while applet loads

    - by Dan
    OK so, let's say I have a Java applet that takes a while to load (~5 secs). It's getting the mysql-connector.jar and it's loading. Well.. instead of the gray box with the coffee logo... can I make it have a simple progress bar with the percent? Thanks.

    Read the article

  • What is the wrong of this converted code?

    - by Gum Slashy
    I'm developing shape identification project using javacv and I have found some opencv code to identify U shapes in particular image and I have try to convert it in to javacv but it doesn't provide same out put. Can you please help me to convert this opencv code into javacv? This is Opencv code import cv2 import numpy as np img = cv2.imread('sofud.jpg') gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) ret,thresh = cv2.threshold(gray,127,255,1) contours,hierarchy = cv2.findContours(thresh,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE) for cnt in contours: x,y,w,h = cv2.boundingRect(cnt) if 10 < w/float(h) or w/float(h) < 0.1: cv2.rectangle(img,(x,y),(x+w,y+h),(0,0,255),2) cv2.imshow('res',img) cv2.waitKey(0) cv2.destroyAllWindows() This is the expected output This is the code that I have converted import com.googlecode.javacpp.Loader; import com.googlecode.javacv.CanvasFrame; import static com.googlecode.javacpp.Loader.*; import static com.googlecode.javacv.cpp.opencv_core.*; import static com.googlecode.javacv.cpp.opencv_imgproc.*; import static com.googlecode.javacv.cpp.opencv_highgui.*; import java.io.File; import javax.swing.JFileChooser; public class TestBeam { public static void main(String[] args) { CvMemStorage storage=CvMemStorage.create(); CvSeq squares = new CvContour(); squares = cvCreateSeq(0, sizeof(CvContour.class), sizeof(CvSeq.class), storage); JFileChooser f=new JFileChooser(); int result=f.showOpenDialog(f);//show dialog box to choose files File myfile=null; String path=""; if(result==0){ myfile=f.getSelectedFile();//selected file taken to myfile path=myfile.getAbsolutePath();//get the path of the file } IplImage src = cvLoadImage(path);//hear path is actual path to image IplImage grayImage = IplImage.create(src.width(), src.height(), IPL_DEPTH_8U, 1); cvCvtColor(src, grayImage, CV_RGB2GRAY); cvThreshold(grayImage, grayImage, 127, 255, CV_THRESH_BINARY); CvSeq cvSeq=new CvSeq(); CvMemStorage memory=CvMemStorage.create(); cvFindContours(grayImage, memory, cvSeq, Loader.sizeof(CvContour.class), CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE); System.out.println(cvSeq.total()); for (int i = 0; i < cvSeq.total(); i++) { CvRect rect=cvBoundingRect(cvSeq, i); int x=rect.x(),y=rect.y(),h=rect.height(),w=rect.width(); if (10 < (w/h) || (w/h) < 0.1){ cvRectangle(src, cvPoint(x, y), cvPoint(x+w, y+h), CvScalar.RED, 1, CV_AA, 0); //cvSeqPush(squares, rect); } } CanvasFrame cnvs=new CanvasFrame("Beam"); cnvs.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE); cnvs.showImage(src); //cvShowImage("Final ", src); } } This is the out put that I got please can some one help me to solve this problem ?

    Read the article

  • jQuery multiple class selection

    - by morpheous
    I am a bit confused with this: I have a page with a set of buttons (i.e. elements with class attribute 'button'. The buttons belong to one of two classes (grp1 and grp2). These are my requirements For buttons with class enabled, when the mouse hovers over them, a 'button-hover' class is added to them (i.e. the element the mouse is hovering over). Otherwise, the hover event is ignored When one of the buttons with class grp2 is clicked on (it has to be 'enabled' first), then I disable (i.e. remove the 'enabled' class for all elements with class 'enabled' (should probably selecting for elements with class 'button' AND 'enabled' - but I am having enough problems as it is, so I need to keep things simple for now). This is what my page looks like: <html> <head> <title>Demo</title> <style type="text/css" .button {border: 1px solid gray; color: gray} .enabled {border: 1px solid red; color: red} .button-hover {background-color: blue; } </style> <script type="text/javascript" src="jquery.js"></script> </head> <body> <div class="btn-cntnr"> <span class="grp1 button enabled">button 1</span> <span class="grp2 button enabled">button 2</span> <span class="grp2 button enabled">button 3</span> <span class="grp2 button enabled">button 4</span> </div> <script type="text/javascript"> /* <![CDATA[ */ $(document).ready(function(){ $(".button.enabled").hover(function(){ $(this).toggleClass('button-hover'); }, function() { $(this).toggleClass('button-hover'); }); $('.grp2.enabled').click(function(){ $(".grp2").removeClass('enabled');} }); /* ]]> */ </script> </body> </html> Currently, when a button with class 'grp2' is clicked on, the other elements with class 'grp2' have the 'enabled' class removed (works correctly). HOWEVER, I notice that even though the class no longer have a 'enabled' class, SOMEHOW, the hover behaviour is still applied to these elemets (WRONG). Once an element has been 'disabled', I no longer want it to respond to the hover() event. How may I implement this behavior, and what is wrong with the code above (i.e. why is it not working? (I am still learning jQuery)

    Read the article

  • How to convert a one column integer data file into a mask for image

    - by gavishna
    I have a data file which contains integers say in range 0-255 containing about 1000 integers which are random in nature.I want to use that as a mask or to multiply an image which is in RGb and another image which is in gray format. HOw do i go about this, how do i convert/represent this data file in matrix format of image dimension ?Kindly suggest. also is it possible to obtain a 3D histogram?

    Read the article

  • how to change color of table view title

    - by madhavi
    hello, Can we change the color of the table view title the string which i am showing appears in gray color can we choose color for it .Is there any property of table view title i am not asking for table view header or footer i mean the title - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { // Keep space in the following line ........ DONT REMOVE return [NSString stringWithFormat:@"Select your service:"]; }

    Read the article

  • Not able to select a row in my ListView

    - by Krishna Thota
    I'm not able to select a row in my list Item Here is my code <Grid DockPanel.Dock="Left" MinWidth="250"> <ListView x:Name="ListVendors" ItemsSource="{Binding SourceCollection}"> <ListView.View> <GridView> <GridView.ColumnHeaderContainerStyle> <Style><Setter Property="FrameworkElement.Visibility" Value="Collapsed"/></Style> </GridView.ColumnHeaderContainerStyle> <GridViewColumn> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions> <TextBlock Grid.Row="0" Text="{Binding Name}" FontSize="20"/> <TextBlock Grid.Row="1" Text="{Binding Code}" Foreground="Gray" /> <TextBlock Grid.Row="2" Text="{Binding ContactNo}" Foreground="Gray" /> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <Grid.RowDefinitions> <RowDefinition /> </Grid.RowDefinitions> <TextBlock Grid.Row="0" Text="{Binding Path=Address, Converter={StaticResource addNewLineConv}}" Grid.RowSpan="3" /> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <Grid.RowDefinitions> <RowDefinition /> </Grid.RowDefinitions> <TextBlock Grid.Row="2" Text="{Binding Email}"/> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn DisplayMemberBinding="{Binding Email}" Header="Email"/> </GridView> </ListView.View> </ListView> How can I select a row in this ListView?

    Read the article

  • Books and shellcode examples

    - by Xor
    i read "art of exploitation" and "gray hat hackers".Both these books examples written for x86 systems.i have a centrino laptop and an amd64 pc.I can't make work examples for stack based overflow.

    Read the article

  • Table sorting & pagination with jQuery and Razor in ASP.NET MVC

    - by hajan
    Introduction jQuery enjoys living inside pages which are built on top of ASP.NET MVC Framework. The ASP.NET MVC is a place where things are organized very well and it is quite hard to make them dirty, especially because the pattern enforces you on purity (you can still make it dirty if you want so ;) ). We all know how easy is to build a HTML table with a header row, footer row and table rows showing some data. With ASP.NET MVC we can do this pretty easy, but, the result will be pure HTML table which only shows data, but does not includes sorting, pagination or some other advanced features that we were used to have in the ASP.NET WebForms GridView. Ok, there is the WebGrid MVC Helper, but what if we want to make something from pure table in our own clean style? In one of my recent projects, I’ve been using the jQuery tablesorter and tablesorter.pager plugins that go along. You don’t need to know jQuery to make this work… You need to know little CSS to create nice design for your table, but of course you can use mine from the demo… So, what you will see in this blog is how to attach this plugin to your pure html table and a div for pagination and make your table with advanced sorting and pagination features.   Demo Project Resources The resources I’m using for this demo project are shown in the following solution explorer window print screen: Content/images – folder that contains all the up/down arrow images, pagination buttons etc. You can freely replace them with your own, but keep the names the same if you don’t want to change anything in the CSS we will built later. Content/Site.css – The main css theme, where we will add the theme for our table too Controllers/HomeController.cs – The controller I’m using for this project Models/Person.cs – For this demo, I’m using Person.cs class Scripts – jquery-1.4.4.min.js, jquery.tablesorter.js, jquery.tablesorter.pager.js – required script to make the magic happens Views/Home/Index.cshtml – Index view (razor view engine) the other items are not important for the demo. ASP.NET MVC 1. Model In this demo I use only one Person class which defines Person entity with several properties. You can use your own model, maybe one which will access data from database or any other resource. Person.cs public class Person {     public string Name { get; set; }     public string Surname { get; set; }     public string Email { get; set; }     public int? Phone { get; set; }     public DateTime? DateAdded { get; set; }     public int? Age { get; set; }     public Person(string name, string surname, string email,         int? phone, DateTime? dateadded, int? age)     {         Name = name;         Surname = surname;         Email = email;         Phone = phone;         DateAdded = dateadded;         Age = age;     } } 2. View In our example, we have only one Index.chtml page where Razor View engine is used. Razor view engine is my favorite for ASP.NET MVC because it’s very intuitive, fluid and keeps your code clean. 3. Controller Since this is simple example with one page, we use one HomeController.cs where we have two methods, one of ActionResult type (Index) and another GetPeople() used to create and return list of people. HomeController.cs public class HomeController : Controller {     //     // GET: /Home/     public ActionResult Index()     {         ViewBag.People = GetPeople();         return View();     }     public List<Person> GetPeople()     {         List<Person> listPeople = new List<Person>();                  listPeople.Add(new Person("Hajan", "Selmani", "[email protected]", 070070070,DateTime.Now, 25));                     listPeople.Add(new Person("Straight", "Dean", "[email protected]", 123456789, DateTime.Now.AddDays(-5), 35));         listPeople.Add(new Person("Karsen", "Livia", "[email protected]", 46874651, DateTime.Now.AddDays(-2), 31));         listPeople.Add(new Person("Ringer", "Anne", "[email protected]", null, DateTime.Now, null));         listPeople.Add(new Person("O'Leary", "Michael", "[email protected]", 32424344, DateTime.Now, 44));         listPeople.Add(new Person("Gringlesby", "Anne", "[email protected]", null, DateTime.Now.AddDays(-9), 18));         listPeople.Add(new Person("Locksley", "Stearns", "[email protected]", 2135345, DateTime.Now, null));         listPeople.Add(new Person("DeFrance", "Michel", "[email protected]", 235325352, DateTime.Now.AddDays(-18), null));         listPeople.Add(new Person("White", "Johnson", null, null, DateTime.Now.AddDays(-22), 55));         listPeople.Add(new Person("Panteley", "Sylvia", null, 23233223, DateTime.Now.AddDays(-1), 32));         listPeople.Add(new Person("Blotchet-Halls", "Reginald", null, 323243423, DateTime.Now, 26));         listPeople.Add(new Person("Merr", "South", "[email protected]", 3232442, DateTime.Now.AddDays(-5), 85));         listPeople.Add(new Person("MacFeather", "Stearns", "[email protected]", null, DateTime.Now, null));         return listPeople;     } }   TABLE CSS/HTML DESIGN Now, lets start with the implementation. First of all, lets create the table structure and the main CSS. 1. HTML Structure @{     Layout = null;     } <!DOCTYPE html> <html> <head>     <title>ASP.NET & jQuery</title>     <!-- referencing styles, scripts and writing custom js scripts will go here --> </head> <body>     <div>         <table class="tablesorter">             <thead>                 <tr>                     <th> value </th>                 </tr>             </thead>             <tbody>                 <tr>                     <td>value</td>                 </tr>             </tbody>             <tfoot>                 <tr>                     <th> value </th>                 </tr>             </tfoot>         </table>         <div id="pager">                      </div>     </div> </body> </html> So, this is the main structure you need to create for each of your tables where you want to apply the functionality we will create. Of course the scripts are referenced once ;). As you see, our table has class tablesorter and also we have a div with id pager. In the next steps we will use both these to create the needed functionalities. The complete Index.cshtml coded to get the data from controller and display in the page is: <body>     <div>         <table class="tablesorter">             <thead>                 <tr>                     <th>Name</th>                     <th>Surname</th>                     <th>Email</th>                     <th>Phone</th>                     <th>Date Added</th>                 </tr>             </thead>             <tbody>                 @{                     foreach (var p in ViewBag.People)                     {                                 <tr>                         <td>@p.Name</td>                         <td>@p.Surname</td>                         <td>@p.Email</td>                         <td>@p.Phone</td>                         <td>@p.DateAdded</td>                     </tr>                     }                 }             </tbody>             <tfoot>                 <tr>                     <th>Name</th>                     <th>Surname</th>                     <th>Email</th>                     <th>Phone</th>                     <th>Date Added</th>                 </tr>             </tfoot>         </table>         <div id="pager" style="position: none;">             <form>             <img src="@Url.Content("~/Content/images/first.png")" class="first" />             <img src="@Url.Content("~/Content/images/prev.png")" class="prev" />             <input type="text" class="pagedisplay" />             <img src="@Url.Content("~/Content/images/next.png")" class="next" />             <img src="@Url.Content("~/Content/images/last.png")" class="last" />             <select class="pagesize">                 <option selected="selected" value="5">5</option>                 <option value="10">10</option>                 <option value="20">20</option>                 <option value="30">30</option>                 <option value="40">40</option>             </select>             </form>         </div>     </div> </body> So, mainly the structure is the same. I have added @Razor code to create table with data retrieved from the ViewBag.People which has been filled with data in the home controller. 2. CSS Design The CSS code I’ve created is: /* DEMO TABLE */ body {     font-size: 75%;     font-family: Verdana, Tahoma, Arial, "Helvetica Neue", Helvetica, Sans-Serif;     color: #232323;     background-color: #fff; } table { border-spacing:0; border:1px solid gray;} table.tablesorter thead tr .header {     background-image: url(images/bg.png);     background-repeat: no-repeat;     background-position: center right;     cursor: pointer; } table.tablesorter tbody td {     color: #3D3D3D;     padding: 4px;     background-color: #FFF;     vertical-align: top; } table.tablesorter tbody tr.odd td {     background-color:#F0F0F6; } table.tablesorter thead tr .headerSortUp {     background-image: url(images/asc.png); } table.tablesorter thead tr .headerSortDown {     background-image: url(images/desc.png); } table th { width:150px;            border:1px outset gray;            background-color:#3C78B5;            color:White;            cursor:pointer; } table thead th:hover { background-color:Yellow; color:Black;} table td { width:150px; border:1px solid gray;} PAGINATION AND SORTING Now, when everything is ready and we have the data, lets make pagination and sorting functionalities 1. jQuery Scripts referencing <link href="@Url.Content("~/Content/Site.css")" rel="stylesheet" type="text/css" /> <script src="@Url.Content("~/Scripts/jquery-1.4.4.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.tablesorter.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.tablesorter.pager.js")" type="text/javascript"></script> 2. jQuery Sorting and Pagination script   <script type="text/javascript">     $(function () {         $("table.tablesorter").tablesorter({ widthFixed: true, sortList: [[0, 0]] })         .tablesorterPager({ container: $("#pager"), size: $(".pagesize option:selected").val() });     }); </script> So, with only two lines of code, I’m using both tablesorter and tablesorterPager plugins, giving some options to both these. Options added: tablesorter - widthFixed: true – gives fixed width of the columns tablesorter - sortList[[0,0]] – An array of instructions for per-column sorting and direction in the format: [[columnIndex, sortDirection], ... ] where columnIndex is a zero-based index for your columns left-to-right and sortDirection is 0 for Ascending and 1 for Descending. A valid argument that sorts ascending first by column 1 and then column 2 looks like: [[0,0],[1,0]] (source: http://tablesorter.com/docs/) tablesorterPager – container: $(“#pager”) – tells the pager container, the div with id pager in our case. tablesorterPager – size: the default size of each page, where I get the default value selected, so if you put selected to any other of the options in your select list, you will have this number of rows as default per page for the table too. END RESULTS 1. Table once the page is loaded (default results per page is 5 and is automatically sorted by 1st column as sortList is specified) 2. Sorted by Phone Descending 3. Changed pagination to 10 items per page 4. Sorted by Phone and Name (use SHIFT to sort on multiple columns) 5. Sorted by Date Added 6. Page 3, 5 items per page   ADDITIONAL ENHANCEMENTS We can do additional enhancements to the table. We can make search for each column. I will cover this in one of my next blogs. Stay tuned. DEMO PROJECT You can download demo project source code from HERE.CONCLUSION Once you finish with the demo, run your page and open the source code. You will be amazed of the purity of your code.Working with pagination in client side can be very useful. One of the benefits is performance, but if you have thousands of rows in your tables, you will get opposite result when talking about performance. Hence, sometimes it is nice idea to make pagination on back-end. So, the compromise between both approaches would be best to combine both of them. I use at most up to 500 rows on client-side and once the user reach the last page, we can trigger ajax postback which can get the next 500 rows using server-side pagination of the same data. I would like to recommend the following blog post http://weblogs.asp.net/gunnarpeipman/archive/2010/09/14/returning-paged-results-from-repositories-using-pagedresult-lt-t-gt.aspx, which will help you understand how to return page results from repository. I hope this was helpful post for you. Wait for my next posts ;). Please do let me know your feedback. Best Regards, Hajan

    Read the article

  • MySQL FULLTEXT not working

    - by Ross
    I'm attempting to add searching support for my PHP web app using MySQL's FULLTEXT indexes. I created a test table (using the MyISAM type, with a single text field a) and entered some sample data. Now if I'm right the following query should return both those rows: SELECT * FROM test WHERE MATCH(a) AGAINST('databases') However it returns none. I've done a bit of research and I'm doing everything right as far as I can tell - the table is a MyISAM table, the FULLTEXT indexes are set. I've tried running the query from the prompt and from phpMyAdmin, with no luck. Am I missing something crucial? UPDATE: Ok, while Cody's solution worked in my test case it doesn't seem to work on my actual table: CREATE TABLE IF NOT EXISTS `uploads` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` text NOT NULL, `size` int(11) NOT NULL, `type` text NOT NULL, `alias` text NOT NULL, `md5sum` text NOT NULL, `uploaded` datetime NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=6 ; And the data I'm using: INSERT INTO `uploads` (`id`, `name`, `size`, `type`, `alias`, `md5sum`, `uploaded`) VALUES (1, '04 Sickman.mp3', 5261182, 'audio/mp3', '1', 'df2eb6a360fbfa8e0c9893aadc2289de', '2009-07-14 16:08:02'), (2, '07 Dirt.mp3', 5056435, 'audio/mp3', '2', 'edcb873a75c94b5d0368681e4bd9ca41', '2009-07-14 16:08:08'), (3, 'header_bg2.png', 16765, 'image/png', '3', '5bc5cb5c45c7fa329dc881a8476a2af6', '2009-07-14 16:08:30'), (4, 'page_top_right2.png', 5299, 'image/png', '4', '53ea39f826b7c7aeba11060c0d8f4e81', '2009-07-14 16:08:37'), (5, 'todo.txt', 392, 'text/plain', '5', '7ee46db77d1b98b145c9a95444d8dc67', '2009-07-14 16:08:46'); The query I'm now running is: SELECT * FROM `uploads` WHERE MATCH(name) AGAINST ('header' IN BOOLEAN MODE) Which should return row 3, header_bg2.png. Instead I get another empty result set. My options for boolean searching are below: mysql> show variables like 'ft_%'; +--------------------------+----------------+ | Variable_name | Value | +--------------------------+----------------+ | ft_boolean_syntax | + -><()~*:""&| | | ft_max_word_len | 84 | | ft_min_word_len | 4 | | ft_query_expansion_limit | 20 | | ft_stopword_file | (built-in) | +--------------------------+----------------+ 5 rows in set (0.02 sec) "header" is within the word length restrictions and I doubt it's a stop word (I'm not sure how to get the list). Any ideas?

    Read the article

  • Silverlight MEF – Download On Demand

    - by PeterTweed
    Take the Slalom Challenge at www.slalomchallenge.com! A common challenge with building complex applications in Silverlight is the initial download size of the xap file.  MEF enables us to build composable applications that allows us to build complex composite applications.  Wouldn’t it be great if we had a mechanism to spilt out components into different Silverlight applications in separate xap files and download the separate xap file only if needed?   MEF gives us the ability to do this.  This post will cover the basics needed to build such a composite application split between different silerlight applications and download the referenced silverlight application only when needed. Steps: 1.     Create a Silverlight 4 application 2.     Add references to the following assemblies: System.ComponentModel.Composition.dll System.ComponentModel.Composition.Initialization.dll 3.     Add a new Silverlight 4 application called ExternalSilverlightApplication to the solution that was created in step 1.  Ensure the new application is hosted in the web application for the solution and choose to not create a test page for the new application. 4.     Delete the App.xaml and MainPage.xaml files – they aren’t needed. 5.     Add references to the following assemblies in the ExternalSilverlightApplication project: System.ComponentModel.Composition.dll System.ComponentModel.Composition.Initialization.dll 6.     Ensure the two references above have their Copy Local values set to false.  As we will have these two assmblies in the original Silverlight application, we will have no need to include them in the built ExternalSilverlightApplication build. 7.     Add a new user control called LeftControl to the ExternalSilverlightApplication project. 8.     Replace the LayoutRoot Grid with the following xaml:     <Grid x:Name="LayoutRoot" Background="Beige" Margin="40" >         <Button Content="Left Content" Margin="30"></Button>     </Grid> 9.     Add the following statement to the top of the LeftControl.xaml.cs file using System.ComponentModel.Composition; 10.   Add the following attribute to the LeftControl class     [Export(typeof(LeftControl))]   This attribute tells MEF that the type LeftControl will be exported – i.e. made available for other applications to import and compose into the application. 11.   Add a new user control called RightControl to the ExternalSilverlightApplication project. 12.   Replace the LayoutRoot Grid with the following xaml:     <Grid x:Name="LayoutRoot" Background="Green" Margin="40"  >         <TextBlock Margin="40" Foreground="White" Text="Right Control" FontSize="16" VerticalAlignment="Center" HorizontalAlignment="Center" ></TextBlock>     </Grid> 13.   Add the following statement to the top of the RightControl.xaml.cs file using System.ComponentModel.Composition; 14.   Add the following attribute to the RightControl class     [Export(typeof(RightControl))] 15.   In your original Silverlight project add a reference to the ExternalSilverlightApplication project. 16.   Change the reference to the ExternalSilverlightApplication project to have it’s Copy Local value = false.  This will ensure that the referenced ExternalSilverlightApplication Silverlight application is not included in the original Silverlight application package when it it built.  The ExternalSilverlightApplication Silverlight application therefore has to be downloaded on demand by the original Silverlight application for it’s controls to be used. 1.     In your original Silverlight project add the following xaml to the LayoutRoot Grid in MainPage.xaml:         <Grid.RowDefinitions>             <RowDefinition Height="65*" />             <RowDefinition Height="235*" />         </Grid.RowDefinitions>         <Button Name="LoaderButton" Content="Download External Controls" Click="Button_Click"></Button>         <StackPanel Grid.Row="1" Orientation="Horizontal" HorizontalAlignment="Center" >             <Border Name="LeftContent" Background="Red" BorderBrush="Gray" CornerRadius="20"></Border>             <Border Name="RightContent" Background="Red" BorderBrush="Gray" CornerRadius="20"></Border>         </StackPanel>       The borders will hold the controls that will be downlaoded, imported and composed via MEF when the button is clicked. 2.     Add the following statement to the top of the MainPage.xaml.cs file using System.ComponentModel.Composition; 3.     Add the following properties to the MainPage class:         [Import(typeof(LeftControl))]         public LeftControl LeftUserControl { get; set; }         [Import(typeof(RightControl))]         public RightControl RightUserControl { get; set; }   This defines properties accepting LeftControl and RightControl types.  The attrributes are used to tell MEF the discovered type that should be applied to the property when composition occurs. 17.   Add the following event handler for the button click to the MainPage.xaml.cs file:         private void Button_Click(object sender, RoutedEventArgs e)         {                   DeploymentCatalog deploymentCatalog =     new DeploymentCatalog("ExternalSilverlightApplication.xap");                   CompositionHost.Initialize(deploymentCatalog);                   deploymentCatalog.DownloadCompleted += (s, i) =>                 {                     if (i.Error == null)                     {                         CompositionInitializer.SatisfyImports(this);                           LeftContent.Child = LeftUserControl;                         RightContent.Child = RightUserControl;                         LoaderButton.IsEnabled = false;                     }                 };                   deploymentCatalog.DownloadAsync();         } This is where the magic happens!  The deploymentCatalog object is pointed to the ExternalSilverlightApplication.xap file.  It is then associated with the CompositionHost initialization.  As the download will be asynchronous, an eventhandler is created for the DownloadCompleted event.  The deploymentCatalog object is then told to start the asynchronous download. The event handler that executes when the download is completed uses the CompositionInitializer.SatisfyImports() function to tell MEF to satisfy the Imports for the current class.  It is at this point that the LeftUserControl and RightUserControl properties are initialized with composed objects from the downloaded ExternalSilverlightApplication.xap package. 18.   Run the application click the Download External Controls button and see the controls defined in the ExternalSilverlightApplication application loaded into the original Silverlight application. Congratulations!  You have implemented download on demand capabilities for composite applications using the MEF DeploymentCatalog class.  You are now able to segment your applications into separate xap file for deployment.

    Read the article

< Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >