.net-4.0

问题 I'm experiencing some difficulties with a WCF RIA Services similar to the problem specified in this thread. The domainservice method I'm creating (a Query method) should take a complex object parameter. example domainservice method: public ComplexObjectResult GetComplexObject(ComplexObjectParameter test) { //do stuff } the parameter object: public class ComplexObjectParameter { [Key] public decimal ID { get; set; } ... other fields } I get this compilation error: Error 70 Parameter 'test' of

问题 .NET 4, console application. The project is set to 'Debug' mode. The breakpoint being set is in the primary/startup project. I have right-clicked -> Clean, and right-clicked -> rebuild, both on the Solution and project levels. Following the instructions in this SO question, I have confirmed that my "Build and Run" options are set to 'prompt' for both 'When projects are out of date' and 'when build or deployment errors occur', and I am NOT getting a prompt when I F5 to build/run. Also, the

问题 When working with files in C#, I am conditioned to think about freeing the associated resources. Usually this is a using statement, unless its a one liner convenience method like File.ReadAllLines, which will open and close the file for me. .Net 4.0 has introduced the convenience method File.ReadLines. This returns an IEnumerable and is billed as a more efficient way to process a file - it avoids storing the entire file in memory. To do this I'm assuming there is some deferred execution logic

问题 Hi I’m trying to use a DataGridView for the first time and with LINQ. Here’s what I’m trying to do: I want to use it (although it doesn’t have to the DataGridView ) to read and display the contents of an XML file (this bit is working code below) but I want to have an add row button on the form or in the DataGridView that takes the contents of three textboxes and and populates the contents of three columns of the new row. The new row is to be appended to the existing data. Next I would like to

问题 Hi I’m trying to use a DataGridView for the first time and with LINQ. Here’s what I’m trying to do: I want to use it (although it doesn’t have to the DataGridView ) to read and display the contents of an XML file (this bit is working code below) but I want to have an add row button on the form or in the DataGridView that takes the contents of three textboxes and and populates the contents of three columns of the new row. The new row is to be appended to the existing data. Next I would like to

问题 I got a REST WCF Service running in .net 4 and I've tested the web service it is working and accepting HttpRequest I make to it. But I ran into a problem trying to access the HttpRequest body within the web service. I've tried sending random sizes of data appended on the HttpRequest using both Fiddler and my WinForm app and I can't seem to find any objects in runtime where I can find my request body is located. My initial instinct was to look in the HttpContext.Current.Request.InputStream but

问题 This question already has answers here : Closed 9 years ago . Possible Duplicate: Are .NET 4.0 Runtime slower than .NET 2.0 Runtime? Hello All, We are planning to move to .NET framework 4.0 sometime soon... I don't remember the refernce or link, but recently, I read about the latest framework being a little slow in performance when compared to its predecessors. Is that true? has anybody done any tests or have some valid arguments to support this? 回答1: It is impossible to make a general

问题 Microsoft has updated the async/await targeting for .net 4.0 and now suggests using the Microsoft.Bcl.Async library available on nuget. In the release notes, it states that .net 4 with KB 2468871 is required. Is KB2468871 a build requirement or a deployment requirement? What aspect of KB2468871 makes it required? 回答1: Quoting from http://support.microsoft.com/kb/2468871/en-us Feature 5 Changes to the support portable libraries. These changes include API updates and binder modifications. This

问题 I have an application in which I am using XPathNavigator to iterate nodes. It is working fine. But I want to know that if I use LINQ to Xml.... What benefits(Performance, maintainability) I will get? With XPath, LINQ to Xml what is the performance hit? I am using C#.net, VS 2010 and my .xml is mid size. 回答1: Well, XPathNavigator will generally be faster than Linq to XML queries. But there's always 'but'. Linq to XML will definitely make your code more readable and maintainable. It's easier

问题 This question already has answers here : How do I create an expression tree to represent 'String.Contains(“term”)' in C#? (4 answers) Closed 5 years ago . I'm struggling to build an expression tree so I can dynamically do filtering on some data. I have come up with this, but it fails at the var lambda = line foreach (var rule in request.Where.Rules) { var parameterExpression = Expression.Parameter(typeof(string), rule.Field); var left = Expression.Call(parameterExpression, typeof(string)