Search Results

Search found 14080 results on 564 pages for 'known types'.

Page 523/564 | < Previous Page | 519 520 521 522 523 524 525 526 527 528 529 530  | Next Page >

  • Change Label Control Property Based on Data from SqlDataSource Inside a Repeater

    - by Furqan Muhammad Khan
    I am using a repeater control to populate data from SqlDataSource into my custom designed display-box. <asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1" OnDataBinding="Repeater_ItemDataBound"> <HeaderTemplate> </HeaderTemplate> <ItemTemplate> <div class="bubble-content"> <div style="float: left;"> <h2 class="bubble-content-title"><%# Eval("CommentTitle") %></h2> </div> <div style="text-align: right;"> <asp:Label ID="lbl_category" runat="server" Text=""><%# Eval("CommentType") %> </asp:Label> </div> <div style="float: left;"> <p><%# Eval("CommentContent") %></p> </div> </div> </ItemTemplate> <FooterTemplate> </FooterTemplate> </asp:Repeater> <asp:SqlDataSource ID="mySqlDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:myConnectionString %>" SelectCommand="SELECT [CommentTitle],[CommentType],[CommentContent] FROM [Comments] WHERE ([PostId] = @PostId)"> <SelectParameters> <asp:QueryStringParameter Name="PostId" QueryStringField="id" Type="String" /> </SelectParameters> </asp:SqlDataSource> Now, there can be three types of "CommentTypes" in the database. I want to change the CssClass property of "lbl_category" based on the value of [CommentType]. I tried doing this: <asp:Label ID="lbl_category" runat="server" CssClass="<%# Eval("CommentType") %>" Text=""><%# Eval("CommentType") %></asp:Label> But this gives an error: "The server control is not well formed" and haven't been able to find a way to achieve this in the code behind. Can someone please help?

    Read the article

  • C++ copy-construct construct-and-assign question

    - by Andy
    Blockquote Here is an extract from item 56 of the book "C++ Gotchas": It's not uncommon to see a simple initialization of a Y object written any of three different ways, as if they were equivalent. Y a( 1066 ); Y b = Y(1066); Y c = 1066; In point of fact, all three of these initializations will probably result in the same object code being generated, but they're not equivalent. The initialization of a is known as a direct initialization, and it does precisely what one might expect. The initialization is accomplished through a direct invocation of Y::Y(int). The initializations of b and c are more complex. In fact, they're too complex. These are both copy initializations. In the case of the initialization of b, we're requesting the creation of an anonymous temporary of type Y, initialized with the value 1066. We then use this anonymous temporary as a parameter to the copy constructor for class Y to initialize b. Finally, we call the destructor for the anonymous temporary. To test this, I did a simple class with a data member (program attached at the end) and the results were surprising. It seems that for the case of b, the object was constructed by the copy constructor rather than as suggested in the book. Does anybody know if the language standard has changed or is this simply an optimisation feature of the compiler? I was using Visual Studio 2008. Code sample: #include <iostream> class Widget { std::string name; public: // Constructor Widget(std::string n) { name=n; std::cout << "Constructing Widget " << this->name << std::endl; } // Copy constructor Widget (const Widget& rhs) { std::cout << "Copy constructing Widget from " << rhs.name << std::endl; } // Assignment operator Widget& operator=(const Widget& rhs) { std::cout << "Assigning Widget from " << rhs.name << " to " << this->name << std::endl; return *this; } }; int main(void) { // construct Widget a("a"); // copy construct Widget b(a); // construct and assign Widget c("c"); c = a; // copy construct! Widget d = a; // construct! Widget e = "e"; // construct and assign Widget f = Widget("f"); return 0; } Output: Constructing Widget a Copy constructing Widget from a Constructing Widget c Assigning Widget from a to c Copy constructing Widget from a Constructing Widget e Constructing Widget f Copy constructing Widget from f I was most surprised by the results of constructing d and e.

    Read the article

  • Is it any loose coupling mechanism in Objective-C + Cocoa like C# delegates or C++Qt signals+slots?

    - by Eye of Hell
    Hello. For a large programs, the standard way to chalenge a complexity is to divide a program code into small objects. Most of the actual programming languages offer this functionality via classes, so is Objective-C. But after source code is separated into small object, the second challenge is to somehow connect them with each over. Standard approaches, supported by most languages are compositon (one object is a member field of another), inheritance, templates (generics) and callbacks. More cryptic techniques include method-level delagates (C#) and signals+slots (C++Qt). I like the delegates / signals idea, since while connecting two objects i can connect individual methods with each over, without objects knowing anything of each over. For C#, it will look like this: var object1 = new CObject1(); var object2 = new CObject2(); object1.SomethingHappened += object2.HandleSomething; In this code, is object1 calls it's SomethingHappened delegate (like a normal method call) the HandleSomething method of object2 will be called. For C++Qt, it will look like this: var object1 = new CObject1(); var object2 = new CObject2(); connect( object1, SIGNAL(SomethingHappened()), object2, SLOT(HandleSomething()) ); The result will be exactly the same. This technique has some advantages and disadvantages, but generally i like it more than interfaces since if program code base grows i can change connections and add new ones without creating tons of interfaces. After examination of Objective-C i havn't found any way to use this technique i like :(. It seems that Objective-C supports message passing perfectly well, but it requres for object1 to have a pointer to object2 in order to pass it a message. If some object needs to be connected to lots of other objects, in Objective-C i will be forced to give him pointers to each of the objects it must be connected. So, the question :). Is it any approach in Objective-C programming that will closely resemble delegate / signal+slot types of connection, not a 'give first object an entire pointer to second object so it can pass a message to it'. Method-level connections are a bit more preferable to me than object-level connection ^_^.

    Read the article

  • I have to do two seemingly mutually exclusive things on leaving an asp:textbox. Please help me get

    - by aape
    This project has gone from being a simple '99 Ford F-150 to the Homer. I've got controls with a gridview with textboxes for data entry. All the user controls on the pages are in AJAX updatepanels. User types in a database column or budget entity or some other financial thing they want to include in the report. The textboxes in the gridview have autopostback = true set. overly long background info When the user leaves the textbox, during the postback (triggered by onTextChanged) I do some validation back on the server on their entry - regexs, do they have rights to that column, is that column locked, etc. If it fails, I put a error message next to the textbox. If it passes, I wipe out any title or error that used to be next to the code. Focus is getting lost from the postback if they're tabbing out of the box, rather than going to the next textbox in the gridview. So to fix that I need, if their leaving the tb via the tab key, to also figure out what textbox or gridviewrow they're on, if they're not on the last row, and after the validation and labeling, put the focus on the textbox in the next row. I can't figure out how, in ontextchanged, to find what caused me to leave the textbox, so I'm thinking use javascript onkeyup to test the key pressed and then find the next box etc, but the ontextchanged fires first and then the js never does, and also, since the control is all AJAXed, the javascript can't find the textboxes because when you enter the page everything is collapsed (the requirements people loooove to collapse and expand things), and so when it's expanded, all the 'new' textboxes are up in the viewstate stuff in the page source, and not down where javascript can see them. The questions So I'm wondering if I can have an onblur in the javascript that can trigger a postback where I can do my validation and such, and either 1) include the keypressed or pick it out of sender in the event or 2) followup the onblur with onkeyup and somehow figure out what textbox is next on the grid and throw focus there. Or, is there another .NET based approach that could work for this? In terms of tearing the whole thing down and starting from scratch, I couldn't sell that to the bosses, I'm past the point of no return as far as that goes.

    Read the article

  • Merge XML files with configurable rules (context: Maven POMs, Java)

    - by Patrick Bergner
    Hi, I'm currently writing some kind of a Maven POM preprocessor that assembles a POM for a project from multiple input files (basically a template and a module specific file). The files are hierarchically ordered (template = most general, module specific = least general). The problem is now to merge these files into a single POM file. Long story short or if you're not familiar with Maven: a POM looks like this (shortened): <project> <modelVersion>4.0.0</modelVersion> <dependencies> <dependency> <groupId>org.apache.maven</groupId> <artifactId>maven-core</artifactId> </dependency> </dependencies> </project> Basically the merger shall replace all values of the more general file with the values of the more specific file (i.e. singletons, e.g. the <modelVersion> above) but there are certain elements where the merger shall add the more certain element to a parent (i.e. collections, e.g. <dependency> elements shall always be added to the <dependencies> element and no <dependency> element shall be replaced by another). A more detailed example with definition of desired output: File A: <project> <modelVersion>A</modelVersion> <dependencies> <dependency> <groupId>groupIdA</groupId> <artifactId>artifactIdA</artifactId> </dependency> </dependencies> </project> File B: <project> <modelVersion>B</modelVersion> <dependencies> <dependency> <groupId>groupIdB</groupId> <artifactId>artifactIdB</artifactId> </dependency> </dependencies> </project> Desired output: <project> <modelVersion>B</modelVersion> <dependencies> <dependency> <groupId>groupIdA</groupId> <artifactId>artifactIdA</artifactId> </dependency> <dependency> <groupId>groupIdB</groupId> <artifactId>artifactIdB</artifactId> </dependency> </dependencies> </project> The set of collection type elements are known and should be configurable (preferably via a set of XPath expressions). A Java based solution is appreciated. What looked most promising so far was the tool mentioned here but the MERGE action produces something like <dependency> <groupId>groupIdAgroupIdB</groupId> <artifactId>artifactIdAartifactIdB</artifactId> </dependency> when merging, which is not what I need. Any ideas? Thanks for your help!

    Read the article

  • Visual Studio 2010 and Test Driven Development

    - by devoured elysium
    I'm making my first steps in Test Driven Development with Visual Studio. I have some questions regarding how to implement generic classes with VS 2010. First, let's say I want to implement my own version of an ArrayList. I start by creating the following test (I'm using in this case MSTest): [TestMethod] public void Add_10_Items_Remove_10_Items_Check_Size_Is_Zero() { var myArrayList = new MyArrayList<int>(); for (int i = 0; i < 10; ++i) { myArrayList.Add(i); } for (int i = 0; i < 10; ++i) { myArrayList.RemoveAt(0); } int expected = 0; int actual = myArrayList.Size; Assert.AreEqual(expected, actual); } I'm using VS 2010 ability to hit ctrl + . and have it implement classes/methods on the go. I have been getting some trouble when implementing generic classes. For example, when I define an .Add(10) method, VS doesn't know if I intend a generic method(as the class is generic) or an Add(int number) method. Is there any way to differentiate this? The same can happen with return types. Let's assume I'm implementing a MyStack stack and I want to test if after I push and element and pop it, the stack is still empty. We all know pop should return something, but usually, the code of this test shouldn't care for it. Visual Studio would then think that pop is a void method, which in fact is not what one would want. How to deal with this? For each method, should I start by making tests that are "very specific" such as is obvious the method should return something so I don't get this kind of ambiguity? Even if not using the result, should I have something like int popValue = myStack.Pop() ? How should I do tests to generic classes? Only test with one generic kind of type? I have been using ints, as they are easy to use, but should I also test with different kinds of objects? How do you usually approach this? I see there is a popular tool called TestDriven for .NET. With VS 2010 release, is it still useful, or a lot of its features are now part of VS 2010, rendering it kinda useless? Thanks

    Read the article

  • C# Type Casting at Runtimefor Array.SetValue

    - by sprocketonline
    I'm trying to create an array using reflection, and insert values into it. I'm trying to do this for many different types so would like a createAndFillArray function capable of this : Type t1 = typeof(A); Type t2 = typeof(B); double exampleA = 22.5; int exampleB = 43; Array arrA = createAndFillArray(t1, exampleA); Array arrB = createAndFillArray(t2, exampleB); private Array createAndFillArray(Type t, object val){ Array arr = Array.CreateInstance( t, 1); //length 1 in this example only, real-world is of variable length. arr.SetValue( val, 0 ); //this causes the following error: "System.InvalidCastException : Object cannot be stored in an array of this type." return arr; } with the class A being as follows: public class A{ public A(){} private double val; public double Value{ get{ return val; } set{ this.val = value; } } public static implicit operator A(double d){ A a = new A(); a.Value = d; return a; } } and class B being very similar, but with int: public class B{ public B(){} private double val; public double Value{ get{ return val; } set{ this.val = value; } } public static implicit operator B(double d){ B b = new B(); b.Value = d; return b; } } I hoped that the implicit operator would have ensured that the double be converted to class A, or the int to class B, and the error avoided; but this is obviously not so. The above is used in a custom deserialization class, which takes data from a custom data format and fills in the corresponding .Net object properties. I'm doing this via reflection and at runtime, so I think both are unavoidable. I'm targeting the C# 2.0 framework. I've dozens, if not hundreds, of classes similar to A and B, so would prefer to find a solution which improved on the createAndFillArray method rather than a solution which altered these classes.

    Read the article

  • Can I use the same machine as a client and server for SSH?

    - by achraf
    For development tests, I need to setup an SFTP server. So I want to know if it's possible to use the same machine as the client and the server. I tried and I keep getting this error: > Permission denied (publickey). > Connection closed and by running ssh -v agharroud@localhost i get : > OpenSSH_3.8.1p1,OpenSSL 0.9.7d 17 Mar > debug1: Reading configuration data /etc/ssh_config > debug1: Connecting to localhost [127.0.0.1] port 22. > debug1: Connection established. > debug1: identity file /home/agharroud/.ssh/identity type -1 > debug1: identity file /home/agharroud/.ssh/id_rsa type 1 > debug1: identity file /home/agharroud/.ssh/id_dsa type -1 > debug1: Remote protocol version 2.0, remote software version OpenSSH_3.8.1p1 > debug1: match: OpenSSH_3.8.1p1 pat OpenSSH* > debug1: Enabling compatibility mode for protocol 2.0 > debug1: Local version string SSH-2.0-OpenSSH_3.8.1p1 > debug1: SSH2_MSG_KEXINIT sent > debug1: SSH2_MSG_KEXINIT received > debug1: kex:server->client aes128-cbc hmac-md5 none > debug1: kex: client->server aes128-cbc hmac-md5 none > debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent > debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP > debug1: SSH2_MSG_KEX_DH_GEX_INIT sent > debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY > debug1: Host 'localhost' is known and matches the RSA host key. > debug1: Found key in /home/agharroud/.ssh/known_hosts:1 > debug1: ssh_rsa_verify: signature correct > debug1: SSH2_MSG_NEWKEYS sent > debug1: expecting SSH2_MSG_NEWKEYS > debug1: SSH2_MSG_NEWKEYS received > debug1: SSH2_MSG_SERVICE_REQUEST sent > debug1: SSH2_MSG_SERVICE_ACCEPT > received > > ****USAGE WARNING**** > > This is a private computer system. This computer system, including all > related equipment, networks, and network devices (specifically > including Internet access) are provided only for authorized use. This > computer system may be monitored for all lawful purposes, including to > ensure that its use is authorized, for management of the system, to > facilitate protection against unauthorized access, and to verify > security procedures, survivability, and operational security. Monitoring > includes active attacks by authorized entities to test or verify the > security of this system. During monitoring, information may be > examined, recorded, copied and used for authorized purposes. All > information, including personal information, placed or sent over this > system may be monitored. > > Use of this computer system, authorized or unauthorized, > constitutes consent to monitoring of this system. Unauthorized use may > subject you to criminal prosecution. Evidence of unauthorized use collected > during monitoring may be used for administrative, criminal, or other > adverse action. Use of this system constitutes consent to monitoring for > these purposes. > > debug1: Authentications that can continue: publickey > debug1: Next authentication method: publickey > debug1: Trying private key:/home/agharroud/.ssh/identity > debug1: Offering public key:/home/agharroud/.ssh/id_rsa > debug1:Authentications that can continue:publickey > debug1: Trying private key:/home/agharroud/.ssh/id_dsa > debug1: No more authentication methods to try. > Permission denied (publickey). Any ideas about the problem ? thanks !

    Read the article

  • How to send a Java integer in four bytes to another application?

    - by user1468729
    public void routeMessage(byte[] data, int mode) { logger.debug(mode); logger.debug(Integer.toBinaryString(mode)); byte[] message = new byte[8]; ByteBuffer byteBuffer = ByteBuffer.allocate(4); ByteArrayOutputStream baoStream = new ByteArrayOutputStream(); DataOutputStream doStream = new DataOutputStream(baoStream); try { doStream.writeInt(mode); } catch (IOException e) { logger.debug("Error converting mode from integer to bytes.", e); return; } byte [] bytes = baoStream.toByteArray(); bytes[0] = (byte)((mode >>> 24) & 0x000000ff); bytes[1] = (byte)((mode >>> 16) & 0x000000ff); bytes[2] = (byte)((mode >>> 8) & 0x00000ff); bytes[3] = (byte)(mode & 0x000000ff); //bytes = byteBuffer.array(); for (byte b : bytes) { logger.debug(b); } for (int i = 0; i < 4; i++) { //byte tmp = (byte)(mode >> (32 - ((i + 1) * 8))); message[i] = bytes[i]; logger.debug("mode, " + i + ": " + Integer.toBinaryString(message[i])); message[i + 4] = data[i]; } broker.routeMessage(message); } I've tried different ways (as you can see from the commented code) to convert the mode to four bytes to send it via a socket to another application. It works well with integers up to 127 and then again with integers over 256. I believe it has something to do with Java types being signed but don't seem to get it to work. Here are some examples of what the program prints. 127 1111111 0 0 0 127 mode, 0: 0 mode, 1: 0 mode, 2: 0 mode, 3: 1111111 128 10000000 0 0 0 -128 mode, 0: 0 mode, 1: 0 mode, 2: 0 mode, 3: 11111111111111111111111110000000 211 11010011 0 0 0 -45 mode, 0: 0 mode, 1: 0 mode, 2: 0 mode, 3: 11111111111111111111111111010011 306 100110010 0 0 1 50 mode, 0: 0 mode, 1: 0 mode, 2: 1 mode, 3: 110010 How is it suddenly possible for a byte to store 32 bits? How could I fix this?

    Read the article

  • Is typeid of type name always evaluated at compile time in c++ ?

    - by cyril42e
    I wanted to check that typeid is evaluated at compile time when used with a type name (ie typeid(int), typeid(std::string)...). To do so, I repeated in a loop the comparison of two typeid calls, and compiled it with optimizations enabled, in order to see if the compiler simplified the loop (by looking at the execution time which is 1us when it simplifies instead of 160ms when it does not). And I get strange results, because sometimes the compiler simplifies the code, and sometimes it does not. I use g++ (I tried different 4.x versions), and here is the program: #include <iostream> #include <typeinfo> #include <time.h> class DisplayData {}; class RobotDisplay: public DisplayData {}; class SensorDisplay: public DisplayData {}; class RobotQt {}; class SensorQt {}; timespec tp1, tp2; const int n = 1000000000; int main() { int avg = 0; clock_gettime(CLOCK_REALTIME, &tp1); for(int i = 0; i < n; ++i) { // if (typeid(RobotQt) == typeid(RobotDisplay)) // (1) compile time // if (typeid(SensorQt) == typeid(SensorDisplay)) // (2) compile time if (typeid(RobotQt) == typeid(RobotDisplay) || typeid(SensorQt) == typeid(SensorDisplay)) // (3) not compile time ???!!! avg++; else avg--; } clock_gettime(CLOCK_REALTIME, &tp2); std::cout << "time (" << avg << "): " << (tp2.tv_sec-tp1.tv_sec)*1000000000+(tp2.tv_nsec-tp1.tv_nsec) << " ns" << std::endl; } The conditions in which this problem appear are not clear, but: - if there is no inheritance involved, no problem (always compile time) - if I do only one comparison, no problem - the problem only appears only with a disjunction of comparisons if all the terms are false So is there something I didn't get with how typeid works (is it always supposed to be evaluated at compilation time when used with type names?) or may this be a gcc bug in evaluation or optimization? About the context, I tracked down the problem to this very simplified example, but my goal is to use typeid with template types (as partial function template specialization is not possible). Thanks for your help!

    Read the article

  • How to infer the type of a derived class in base class?

    - by enzi
    I want to create a method that allows me to change arbitrary properties of classes that derive from my base class, the result should look like this: SetPropertyValue("size.height", 50); – where size is a property of my derived class and height is a property of size. I'm almost done with my implementation but there's one final obstacle that I want to solve before moving on, to describe this I will first have to explain my implementation a bit: Properties that can be modified are decorated with an attribute There's a method in my base class that searches for all derived classes and their decorated properties For each property I generate a "property modifier", a class that contains 2 delegates: one to set and one to get the value of the property. Property Modifiers are stored in a dictionary, with the name of the property as key In my base class, there is another dictionary that contains all property-modifier-dictionaries, with the Type of the respective class as key. What the SetPropertyValue method does is this: Get the correct property-modifier-dictionary, using the concrete type of the derived class (<- yet to solve) Get the property modifier of the property to change (e.g. of the property size) Use the get or set delegate to modify the property's value Some example code to clarify further: private static Dictionary<RuntimeTypeHandle, object> EditableTypes; //property-modifier-dictionary protected void SetPropertyValue<T>(EditablePropertyMap<T> map, string property, object value) { var property = map[property]; // get the property modifier property.Set((T)this, value); // use the set delegate (encapsulated in a method) } In the above code, T is the Type of the actual (derived) class. I need this type for the get/set delegates. The problem is how to get the EditablePropertyMap<T> when I don't know what T is. My current (ugly) solution is to pass the map in an overriden virtual method in the derived class: public override void SetPropertyValue(string property, object value) { base.SetPropertyValue((EditablePropertyMap<ExampleType>)EditableTypes[typeof(ExampleType)], property, value); } What this does is: get the correct dictionary containing the property modifiers of this class using the class's type, cast it to the appropiate type and pass it to the SetPropertyValue method. I want to get rid of the SetPropertyValue method in my derived class (since there are a lot of derived classes), but don't know yet how to accomplish that. I cannot just make a virtual GetEditablePropertyMap<T> method because I cannot infer a concrete type for T then. I also cannot acces my dictionary directly with a type and retrieve an EditablePropertyMap<T> from it because I cannot cast to it from object in the base class, since again I do not know T. I found some neat tricks to infere types (e.g. by adding a dummy T parameter), but cannot apply them to my specific problem. I'd highly appreciate any suggestions you may have for me.

    Read the article

  • JNA array structure

    - by Burny
    I want to use a dll (IEC driver) in Java, for that I am using JNA. The problem in pseudo code: start the server allocate new memory for an array (JNA) client connect writing values from an array to the memory sending this array to the client client disconnect new client connect allocate new memory for an array (JNA) - JVM crash (EXCEPTION_ACCESS_VIOLATION) The JVM crash not by primitve data types and if the values will not writing from the array to the memory. the code in c: struct DataAttributeData CrvPtsArrayDAData = {0}; CrvPtsArrayDAData.ucType = DATATYPE_ARRAY; CrvPtsArrayDAData.pvData = XYValDAData; XYValDAData[0].ucType = FLOAT; XYValDAData[0].uiBitLength = sizeof(Float32)*8; XYValDAData[0].pvData = &(inUpdateValue.xVal); XYValDAData[1].ucType = FLOAT; XYValDAData[1].uiBitLength = sizeof(Float32)*8; XYValDAData[1].pvData = &(inUpdateValue.yVal); Send(&CrvPtsArrayDAData, 1); the code in Java: DataAttributeData[] data_array = (DataAttributeData[]) new DataAttributeData() .toArray(d.bitLength); for (DataAttributeData d_temp : data_array) { d_temp.data = new Memory(size / 8); d_temp.type = type_iec; d_temp.bitLength = size; d_temp.write(); } d.data = data_array[0].getPointer(); And then writing values whith this code: for (int i = 0; i < arraySize; i++) { DataAttributeData dataAttr = new DataAttributeData(d.data.share(i * d.size())); dataAttr.read(); dataAttr.data.setFloat(0, f[i]); dataAttr.write(); } the struct in c: struct DataAttributeData{ unsigned char ucType; int iArrayIndex; unsigned int uiBitLength; void * pvData;}; the struct in java: public static class DataAttributeData extends Structure { public DataAttributeData(Pointer p) { // TODO Auto-generated constructor stub super(p); } public DataAttributeData() { // TODO Auto-generated constructor stub super(); } public byte type; public int iArrayIndex; public int bitLength; public Pointer data; @Override protected List<String> getFieldOrder() { // TODO Auto-generated method stub return Arrays.asList(new String[] { "type", "iArrayIndex", "bitLength", "data" }); } } Can anybody help me?

    Read the article

  • How come Java doesn't accept my LinkedList in a Generic, but accepts its own?

    - by master chief
    For a class assignment, we can't use any of the languages bultin types, so I'm stuck with my own list. Anyway, here's the situation: public class CrazyStructure <T extends Comparable<? super T>> { MyLinkedList<MyTree<T>> trees; //error: type parameter MyTree is not within its bound } However: public class CrazyStructure <T extends Comparable<? super T>> { LinkedList<MyTree<T>> trees; } Works. MyTree impleements the Comparable interface, but MyLinkedList doesn't. However, Java's LinkedList doesn't implement it either, according to this. So what's the problem and how do I fix it? MyLinkedList: public class MyLinkedList<T extends Comparable<? super T>> { private class Node<T> { private Node<T> next; private T data; protected Node(); protected Node(final T value); } Node<T> firstNode; public MyLinkedList(); public MyLinkedList(T value); //calls node1.value.compareTo(node2.value) private int compareElements(final Node<T> node1, final Node<T> node2); public void insert(T value); public void remove(T value); } MyTree: public class LeftistTree<T extends Comparable<? super T>> implements Comparable { private class Node<T> { private Node<T> left, right; private T data; private int dist; protected Node(); protected Node(final T value); } private Node<T> root; public LeftistTree(); public LeftistTree(final T value); public Node getRoot(); //calls node1.value.compareTo(node2.value) private int compareElements(final Node node1, final Node node2); private Node<T> merge(Node node1, Node node2); public void insert(final T value); public T extractMin(); public int compareTo(final Object param); }

    Read the article

  • c# video equivalent to image.fromstream? Or changing the scope of the following script to allow vide

    - by Daniel
    The following is a part of an upload class in a c# script. I'm a php programmer, I've never messed with c# much but I'm trying to learn. This upload script will not handle anything except images, I need to adapt this class to handle other types of media also, or rewrite it all together. If I'm correct, I realize that using (Image image = Image.FromStream(file.InputStream)) basically says that the scope of the following is Image, only an image can be used or the object is discarded? And also that the variable image is being created from an Image from the file stream, which I understand to be, like... the $_FILES array in php? I dunno, I don't really care about making thumbnails right now either way, so if this can be taken out and still process the upload I'm totally cool with that, I just haven't had any luck getting this thing to take anything but images, even when commenting out that whole part of the class... protected void Page_Load(object sender, EventArgs e) { string dir = Path.Combine(Request.PhysicalApplicationPath, "files"); if (Request.Files.Count == 0) { // No files were posted Response.StatusCode = 500; } else { try { // Only one file at a time is posted HttpPostedFile file = Request.Files[0]; // Size limit 100MB if (file.ContentLength > 102400000) { // File too large Response.StatusCode = 500; } else { string id = Request.QueryString["userId"]; string[] folders = userDir(id); foreach (string folder in folders) { dir = Path.Combine(dir, folder); if (!Directory.Exists(dir)) Directory.CreateDirectory(dir); } string path = Path.Combine(dir, String.Concat(Request.QueryString["batchId"], "_", file.FileName)); file.SaveAs(path); // Create thumbnail int dot = path.LastIndexOf('.'); string thumbpath = String.Concat(path.Substring(0, dot), "_thumb", path.Substring(dot)); using (Image image = Image.FromStream(file.InputStream)) { // Find the ratio that will create maximum height or width of 100px. double ratio = Math.Max(image.Width / 100.0, image.Height / 100.0); using (Image thumb = new Bitmap(image, new Size((int)Math.Round(image.Width / ratio), (int)Math.Round(image.Height / ratio)))) { using (Graphics graphic = Graphics.FromImage(thumb)) { // Make sure thumbnail is not crappy graphic.SmoothingMode = SmoothingMode.HighQuality; graphic.InterpolationMode = InterpolationMode.High; graphic.CompositingQuality = CompositingQuality.HighQuality; // JPEG ImageCodecInfo codec = ImageCodecInfo.GetImageEncoders()[1]; // 90% quality EncoderParameters encode = new EncoderParameters(1); encode.Param[0] = new EncoderParameter(Encoder.Quality, 90L); // Resize graphic.DrawImage(image, new Rectangle(0, 0, thumb.Width, thumb.Height)); // Save thumb.Save(thumbpath, codec, encode); } } } // Success Response.StatusCode = 200; } } catch { // Something went wrong Response.StatusCode = 500; } } }

    Read the article

  • This code appears to achieve the return of a null reference in C++

    - by Chuck
    Hi folks, My C++ knowledge is somewhat piecemeal. I was reworking some code at work. I changed a function to return a reference to a type. Inside, I look up an object based on an identifier passed in, then return a reference to the object if found. Of course I ran into the issue of what to return if I don't find the object, and in looking around the web, many people claim that returning a "null reference" in C++ is impossible. Based on this advice, I tried the trick of returning a success/fail boolean, and making the object reference an out parameter. However, I ran into the roadblock of needing to initialize the references I would pass as actual parameters, and of course there is no way to do this. I retreated to the usual approach of just returning a pointer. I asked a colleague about it. He uses the following trick quite often, which is accepted by both a recent version of the Sun compiler and by gcc: MyType& someFunc(int id) { // successful case here: // ... // fail case: return *static_cast<MyType*>(0); } // Use: ... MyType& mt = somefunc(myIdNum); if (&mt) // test for "null reference" { // whatever } ... I have been maintaining this code base for a while, but I find that I don't have as much time to look up the small details about the language as I would like. I've been digging through my reference book but the answer to this one eludes me. Now, I had a C++ course a few years ago, and therein we emphasized that in C++ everything is types, so I try to keep that in mind when thinking things through. Deconstructing the expression: "*static_cast(0);", it indeed seems to me that we take a literal zero, cast it to a pointer to MyType (which makes it a null pointer), and then apply the dereferencing operator in the context of assigning to a reference type (the return type), which should give me a reference to the same object pointed to by the pointer. This sure looks like returning a null reference to me. Any advice in explaining why this works (or why it shouldn't) would be greatly appreciated. Thanks, Chuck

    Read the article

  • C Named pipe (fifo). Parent process gets stuck

    - by Blitzkr1eg
    I want to make a simple program, that fork, and the child writes into the named pipe and the parent reads and displays from the named pipe. The problem is that it enters the parent, does the first printf and then it gets weird, it doesn't do anything else, does not get to the second printf, it just ways for input in the console. #include <string.h> #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> void main() { char t[100]; mkfifo("myfifo",777); pid_t pid; pid = fork(); if (pid==0) { //execl("fifo2","fifo2",(char*)0); char r[100]; printf("scrie2->"); scanf("%s",r); int fp; fp = open("myfifo",O_WRONLY); write(fp,r,99); close(fp); printf("exit kid \n"); exit(0); } else { wait(0); printf("entered parent \n"); // <- this it prints // whats below this line apparently its not being executed int fz; printf("1"); fz = open("myfifo",O_RDONLY); printf("2"); printf("fd: %d",fz); char p[100]; int size; printf("------"); //struct stat *info; //stat("myfifo",info); printf("%d",(*info).st_size); read(fz,p,99); close(fz); printf("%s",p); printf("exit"); exit(0); } }

    Read the article

  • Effective optimization strategies on modern C++ compilers

    - by user168715
    I'm working on scientific code that is very performance-critical. An initial version of the code has been written and tested, and now, with profiler in hand, it's time to start shaving cycles from the hot spots. It's well-known that some optimizations, e.g. loop unrolling, are handled these days much more effectively by the compiler than by a programmer meddling by hand. Which techniques are still worthwhile? Obviously, I'll run everything I try through a profiler, but if there's conventional wisdom as to what tends to work and what doesn't, it would save me significant time. I know that optimization is very compiler- and architecture- dependent. I'm using Intel's C++ compiler targeting the Core 2 Duo, but I'm also interested in what works well for gcc, or for "any modern compiler." Here are some concrete ideas I'm considering: Is there any benefit to replacing STL containers/algorithms with hand-rolled ones? In particular, my program includes a very large priority queue (currently a std::priority_queue) whose manipulation is taking a lot of total time. Is this something worth looking into, or is the STL implementation already likely the fastest possible? Along similar lines, for std::vectors whose needed sizes are unknown but have a reasonably small upper bound, is it profitable to replace them with statically-allocated arrays? I've found that dynamic memory allocation is often a severe bottleneck, and that eliminating it can lead to significant speedups. As a consequence I'm interesting in the performance tradeoffs of returning large temporary data structures by value vs. returning by pointer vs. passing the result in by reference. Is there a way to reliably determine whether or not the compiler will use RVO for a given method (assuming the caller doesn't need to modify the result, of course)? How cache-aware do compilers tend to be? For example, is it worth looking into reordering nested loops? Given the scientific nature of the program, floating-point numbers are used everywhere. A significant bottleneck in my code used to be conversions from floating point to integers: the compiler would emit code to save the current rounding mode, change it, perform the conversion, then restore the old rounding mode --- even though nothing in the program ever changed the rounding mode! Disabling this behavior significantly sped up my code. Are there any similar floating-point-related gotchas I should be aware of? One consequence of C++ being compiled and linked separately is that the compiler is unable to do what would seem to be very simple optimizations, such as move method calls like strlen() out of the termination conditions of loop. Are there any optimization like this one that I should look out for because they can't be done by the compiler and must be done by hand? On the flip side, are there any techniques I should avoid because they are likely to interfere with the compiler's ability to automatically optimize code? Lastly, to nip certain kinds of answers in the bud: I understand that optimization has a cost in terms of complexity, reliability, and maintainability. For this particular application, increased performance is worth these costs. I understand that the best optimizations are often to improve the high-level algorithms, and this has already been done.

    Read the article

  • Contact form with php-script does not work

    - by elajjas
    I'm new to the forum and I have been trying to find a thread that could be helpful but nothing have been working out so far. I recently uploaded my site via FTP, and it works fine. Except for one thing, my contact form. The contact form is crucial and it is almost the whole point of the website. I don't get any emails "from the form", either in my spam-folder or inbox. Please have a look at the website which is: http://www.adspot.se The contact form is situated on: http://www.adspot.se/contact.html The php script looks like this: <?php if (isset($_REQUEST['email'])) //if "email" is filled out, send email { //send email $name = $_REQUEST['name'] ; $email = $_REQUEST['email'] ; $message = $_REQUEST['message'] ; mail("[email protected]", $name, $message, "From:" . $email); } ?> I've already tried different types of php-scripts, but it still doesn't seem to work. UPDATE: Changed the form code to: <form method="POST" action="email.php"> <div class="row half"> <div class="6u"> <input name="name" placeholder="Name" type="text" class="text" /> </div> <div class="6u"> <input name="email" placeholder="Email" type="text" class="text" /> </div> </div> <div class="row half"> <div class="12u"> <textarea name="message" placeholder="Message"></textarea> </div> </div> <div class="row half"> <div class="12u"> <ul class="action"> <input type="submit" class="action"> </ul> </div> </div> </form> Now it redirects me to www.adspot.se/email.php but still no emails received...

    Read the article

  • [c++] upload image to imageshack

    - by cinek1lol
    Hi. I would like to send pictures via a program written in C + + I wrote such a thing using curl.exe WinExec("C:\\curl\\curl.exe -H Expect: -F \"fileupload=@C:\\curl\\ok.jpg\" -F \"xml=yes\" -# \"http://www.imageshack.us/index.php\" -o data.txt -A \"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1\" -e \"http://www.imageshack.us\"", NULL); This only works that I would like to send pictures to a variable pre-loaded char (you know what I mean? first reads the pictures into a variable and then send that variable), because now I have to specify the path to the images on disk I wanted to make this program was written in C + + using the curl library, and not the exe. I found it such a program (which some have modified) #include <stdio.h> #include <string.h> #include <iostream> #include <curl/curl.h> #include <curl/types.h> #include <curl/easy.h> int main(int argc, char *argv[]) { CURL *curl; CURLcode res; struct curl_httppost *formpost=NULL; struct curl_httppost *lastptr=NULL; struct curl_slist *headerlist=NULL; static const char buf[] = "Expect:"; curl_global_init(CURL_GLOBAL_ALL); /* Fill in the file upload field */ curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "send", CURLFORM_FILE, "nowy.jpg", CURLFORM_END); curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "nowy.jpg", CURLFORM_COPYCONTENTS, "nowy.jpg", CURLFORM_END); curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "submit", CURLFORM_COPYCONTENTS, "send", CURLFORM_END); curl = curl_easy_init(); headerlist = curl_slist_append(headerlist, buf); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "http://www.imageshack.us/index.php"); if ( (argc == 2) && (!strcmp(argv[1], "xml=yes")) ) curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist); curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost); res = curl_easy_perform(curl); curl_easy_cleanup(curl); curl_formfree(formpost); curl_slist_free_all (headerlist); } system("pause"); return 0; } I will be grateful for any help

    Read the article

  • Template class + virtual function = must implement?

    - by sold
    This code: template <typename T> struct A { T t; void DoSomething() { t.SomeFunction(); } }; struct B { }; A<B> a; is easily compiled without any complaints, as long as I never call a.DoSomething(). However, if I define DoSomething as a virtual function, I will get a compile error saying that B doesn't declare SomeFunction. I can somewhat see why it happens (DoSomething should now have an entry in the vtable), but I can't help feeling that it's not really obligated. Plus it sucks. Is there any way to overcome this? EDIT 2: Okay. I hope this time it makes sence: Let's say I am doing intrusive ref count, so all entities must inherit from base class Object. How can I suuport primitive types too? I can define: template <typename T> class Primitive : public Object { T value; public: Primitive(const T &value=T()); operator T() const; Primitive<T> &operator =(const T &value); Primitive<T> &operator +=(const T &value); Primitive<T> &operator %=(const T &value); // And so on... }; so I can use Primitive<int>, Primitive<char>... But how about Primitive<float>? It seems like a problem, because floats don't have a %= operator. But actually, it isn't, since I'll never call operator %= on Primitive<float>. That's one of the deliberate features of templates. If, for some reason, I would define operator %= as virtual. Or, if i'll pre-export Primitive<float> from a dll to avoid link errors, the compiler will complain even if I never call operator %= on a Primitive<float>. If it would just have fill in a dummy value for operator %= in Primitive<float>'s vtable (that raises an exception?), everything would have been fine.

    Read the article

  • execl doesn't work in a while(1) cicle, server side; C script

    - by Possa
    Hi guys, I have a problem with a little C script who should run as a server and launch a popup for every message arriving. The execl syntax is correct because if I try a little script with main() { execl(...); } it works. When I put it in a while(1) cicle it doesn't work. Everything else is working, like printf or string operation, but not the execl. Even if I fork it doesn't work. I really don't know what I can do ... can anyone help me? Thanks in advice for your help and sorry for my bad english. Here's the complete server C code. #include <arpa/inet.h> #include <netinet/in.h> #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <unistd.h> #include <string.h> #define BUFLEN 512 #define PORT 9930 void diep(char *s) { perror(s); exit(1); } int main() { struct sockaddr_in si_me, si_other; int s, i, slen=sizeof(si_other), broadcastPermission; char buf[100], zeni[BUFLEN]; if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1) diep("socket"); broadcastPermission = 1; if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (void *) &broadcastPermission, sizeof(broadcastPermission)) < 0) diep("setsockopt() failed"); memset((char *) &si_me, 0, sizeof(si_me)); si_me.sin_family = AF_INET; si_me.sin_port = htons(PORT); si_me.sin_addr.s_addr = htonl(INADDR_ANY); if (bind(s, &si_me, sizeof(si_me))==-1) diep("bind"); while (1) { if (recvfrom(s, buf, BUFLEN, 0, &si_other, &slen)==-1) diep("recvfrom()"); //printf("Received packet from %s:%d\nData: %s\n", inet_ntoa(si_other.sin_addr), ntohs(si_other.sin_port), buf); strcpy(zeni, ""); strcat(zeni, "zenity --warning --title Hack!! --text "); strcat(zeni, buf); printf("cmd: %s\n", zeni); //system (zeni); execl("/usr/bin/zenity", "/usr/bin/zenity", "--warning", "--title", "Warn!", "--text", buf, (char *) NULL); } close(s); return 0; }

    Read the article

  • Java template classes using generator or similar?

    - by Hugh Perkins
    Is there some library or generator that I can use to generate multiple templated java classes from a single template? Obviously Java does have a generics implementation itself, but since it uses type-erasure, there are lots of situations where it is less than adequate. For example, if I want to make a self-growing array like this: class EasyArray { T[] backingarray; } (where T is a primitive type), then this isn't possible. This is true for anything which needs an array, for example high-performance templated matrix and vector classes. It should probably be possible to write a code generator which takes a templated class and generates multiple instantiations, for different types, eg for 'double' and 'float' and 'int' and 'String'. Is there something that already exists that does this? Edit: note that using an array of Object is not what I'm looking for, since it's no longer an array of primitives. An array of primitives is very fast, and uses only as much space a sizeof(primitive) * length-of-array. An array of object is an array of pointers/references, that points to Double objects, or similar, which could be scattered all over the place in memory, require garbage collection, allocation, and imply a double-indirection for access. Edit2: good god, voted down for asking for something that probably doesn't currently exist, but is technically possible and feasible? Does that mean that people looking for ways to improve things have already left the java community? Edit3: Here is code to show the difference in performance between primitive and boxed arrays: int N = 10*1000*1000; double[]primArray = new double[N]; for( int i = 0; i < N; i++ ) { primArray[i] = 123.0; } Object[] objArray = new Double[N]; for( int i = 0; i < N; i++ ) { objArray[i] = 123.0; } tic(); primArray = new double[N]; for( int i = 0; i < N; i++ ) { primArray[i] = 123.0; } toc(); tic(); objArray = new Double[N]; for( int i = 0; i < N; i++ ) { objArray[i] = 123.0; } toc(); Results: double[] array: 148 ms Double[] array: 4614 ms Not even close!

    Read the article

  • Javascript question

    - by Craig
    I am supposed to make this simple program. It produces a multiplication problem, and when the user types the correct answer, it is supposed to produce another question. Instead it goes into an infinite loop and never stops, the answer field and the button go away. Also, I am supposed to make the comment about the users answer, one of 4 different sayings. Without using Arrays how would I do that? My professor is no help, really getting aggravated as I have no where else to turn. <html> <title>HW 9.27 and 9.28</title> <head> <script type="text/javascript"> var number1; var number2; var answer3; var answer2; function problem() { number1 = Math.floor(1 + Math.random() * 9); number2 = Math.floor(1 + Math.random() * 9); document.writeln("How much is " + number1 + " times " + number2 + " ?"); answer2 = (number1 * number2); } function answer1() { var statusDiv = document.getElementById("status"); answer3 = document.getElementById("answer").value; if (answer3 != answer2) statusDiv.innerHTML = "No. Please try again"; else if (answer3 == answer2) { statusDiv.innerHTML = "Very good!"; problem(); } } problem(); </script> </head> <body> <form> <input id="answer" type="text" /> <input type="button" value="Solve!" onclick="answer1()" /> <div id ="status">Click the Solve button to Solve the problem</div> </form> </body> </html>

    Read the article

  • Not seeing Sync Block in Object Layout

    - by bob-bedell
    It's my understanding the all .NET object instances begin with an 8 byte 'object header': a synch block (4 byte pointer into a SynchTableEntry table), and a type handle (4 byte pointer into the types method table). I'm not seeing this in VS 2010 RC's (CLR 4.0) debugger memory windows. Here's a simple class that will generate a 16 byte instance, less the object header. class Program { short myInt = 2; // 4 bytes long myLong = 3; // 8 bytes string myString = "aString"; // 4 byte object reference // 16 byte instance static void Main(string[] args) { new Program(); return; } } An SOS object dump tells me that the total object size is 24 bytes. That makes sense. My 16 byte instance plus an 8 byte object header. !DumpObj 0205b660 Name: Offset_Test.Program MethodTable: 000d383c EEClass: 000d13f8 Size: 24(0x18) bytes File: C:\Users\Bob\Desktop\Offset_Test\Offset_Test\bin\Debug\Offset_Test.exe Fields: MT Field Offset Type VT Attr Value Name 632020fc 4000001 10 System.Int16 1 instance 2 myInt 632050d8 4000002 4 System.Int64 1 instance 3 myLong 631fd2b8 4000003 c System.String 0 instance 0205b678 myString Here's the raw memory: 0x0205B660 000d383c 00000003 00000000 0205b678 00000002 ... And here are some annotations: offset 0 000d383c ;TypeHandle (pointer to MethodTable), 4 bytes offset 4 00000003 00000000 ;myLong, 8 bytes offset 12 0205b678 ;myString, 4 byte reference to address of "myString" on GC Heap offset 16 00000002 ;myInt, 4 bytes My object begins a address 0x0205B660. But I can only account for 20 bytes of it, the type handle and the instance fields. There is no sign of a synch block pointer. The object size is reported as 24 bytes, but the debugger is showing that it only occupies 20 bytes of memory. I'm reading Drill Into .NET Framework Internals to See How the CLR Creates Runtime Objects, and expected the first 4 bytes of my object to be a zeroed synch block pointer, as shown in Figure 8 of that article. Granted, this is an article about CLR 1.1. I'm just wondering if the difference between what I'm seeing and what this early article reports is a change in either the debugger's display of object layout, or in the way the CLR lays out objects in versions later than 1.1. Anyway, can anyone account for my 4 missing bytes?

    Read the article

  • Can a process have two pid's?

    - by limp_chimp
    I'm studying computer systems and I've made this very simple function which uses fork() to create a child process. fork() returns a pid_t that is 0 if it's a child process. But calling the getpid() function within this child process returns a different, nonzero pid. In the code I have below, is newPid only meaningful in the context of the program, and not to the operating system? Is it possibly only a relative value, measured against the pid of the parent? #include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <string.h> #include <errno.h> #include <stdlib.h> void unixError(char* msg) { printf("%s: %s\n", msg, strerror(errno)); exit(0); } pid_t Fork() { pid_t pid; if ((pid = fork()) < 0) unixError("Fork error"); return pid; } int main(int argc, const char * argv[]) { pid_t thisPid, parentPid, newPid; int count = 0; thisPid = getpid(); parentPid = getppid(); printf("thisPid = %d, parent pid = %d\n", thisPid, parentPid); if ((newPid = Fork()) == 0) { count++; printf("I am teh child. My pid is %d, my other pid is %d\n", getpid(), newPid); exit(0); } printf("I am the parent. My pid is %d\n", thisPid); return 0; } Output: thisPid = 30050, parent pid = 30049 I am the parent. My pid is 30050 I am teh child. My pid is 30052, my other pid is 0 Lastly, why is the child's pid 2 higher than the parent's, and not 1? The difference between the main function's pid and its parent is 1, but when we create a child it increments the pid by 2. Why is that?

    Read the article

< Previous Page | 519 520 521 522 523 524 525 526 527 528 529 530  | Next Page >