Browse questions answered by Jon Skeet

Converting a Predicate<T> to a Func<T, bool>

I have a class with a member Predicate which I would like to use in a Linq expression: using System.Linq; class MyClass { public bool DoAllHaveSomeProperty() { ...

The two types represent the same logical signature, but that doesn't mean they're just interchangable. A straight assignment won't work, for example - but you can create a new Func<T, bool> from the Predicate<T, bool>. Sample... more 8/27/2014 4:07:31 PM

Rounding bug in c#?

I'm having problems with a Rounding issue in c#. I would like to round the result of a calculation up to 4 decimals (awayfromzero). If I use Math.Round(variable,...) it rounds...

If you use my DoubleConverter, you can see the exact value of result: Console.WriteLine(DoubleConverter.ToExactString(result)); That prints: 591.2457499999999299689079634845256805419921875 ... which rounds to 591.2457 when rounded to... more 8/27/2014 3:56:04 PM

How to create public calculation function that returns calculated value?

I would like to create public function, that will be used to calculate some value. I would like the value to be the output of the function, for example: public void...

Currently, you're assigning a value to a variable, and declaring that your method doesn't return anything. Instead, you should just make it return the result: public int calculate(...) { int x = y+z/2 +i; if(x >= 10) { ... more 8/27/2014 2:28:32 PM

Exception in SqlConnection constructor causing exception in finalize

I have the following code: SqlConnection ret = new SqlConnection(connectionString); This throws a ConfigurationException which I catch, however, since the exception occurs in...

I think it's reasonable for an issue in the machine.config file to mean that an app simply can't run. If your system-wide configuration is broken, you (the owner of that broken configuration) should fix it. Not all failures can be... more 8/27/2014 8:12:35 AM

org.w3c.dom.Node.setNodeValue() not encoding certain special characters

Using Java, I set the value of a <value> attribute in an xml file to be String val = "~!@#$%^&*()_+-={}|[]\\:\";'<>?,./;" When I tried to use the api with input...

It's simply because it doesn't need to escape >, ' or ". The quotes would only need to be encoded in an attribute which was opened with the same kind of quote (so foo="single'quote" or bar='double"quote' is fine) and the closing angle... more 8/27/2014 5:53:51 AM

Confused accessing delegate from WPF ui thread

My apologies but I can't see what I am doing wrong / not understanding? I have declared a delegate such as: namespace ABC { public delegate void GenerateView(); public...

The reason your current code doesn't work is that handler is just a local variable within the constructor. While you could add a public property, if the point is just for external code to be able to get a delegate which calls... more 8/27/2014 5:46:16 AM

Instantiate a Generic class via Reflection

I want to instantiate a class via reflection as follows: public class TestConsume<T> : BaseExecutor<T> { public overide SomeMethod(T input) { } } Where the...

To get Assembly.GetType to work, you need to use the CLR name, which includes the generic arity - the number of type parameters it has: Type type = Assembly.GetExecutingAssembly().GetType("Test.TestConsume`1"); That's assuming you need... more 8/26/2014 8:47:15 PM

DateTime.Date get me Date and 12:00 AM

I have already seen this. I am going to get only Date from a DateTime variable and in this way I used this code: DateTime Start = GetaDateTime(); String Day =...

Actually I should not get 12:00AM any more???? Why not? A DateTime has no notion of whether it's meant to be a date or a date and time, or any sort of string formatting. It's just a point in time (and not even quite that, given the... more 8/26/2014 7:58:05 PM

Reading xml string with c#

I have the following soap response string: <EncryptionInfoResponse> <Status>0</Status> <Message></Message>...

The problem is that you're using XElement.Parse, so you're parsing the string as an element... so xdoc is already the EncryptionInfoResponse element, which doesn't have any more EncryptionInfoResponse descendants. Options: Use... more 8/26/2014 7:49:57 PM

Instance Method Reference and Lambda Parameters

I am having trouble understanding the syntax for a method reference, where there are two parameters a and b, and the reference is to a method of a on b. For example I understand...

I think you're looking for JLS section 15.13.3, which includes: If the form is ReferenceType :: [TypeArguments] Identifier, the body of the invocation method similarly has the effect of a method invocation expression for a compile-time... more 8/26/2014 6:20:57 PM