Why must a lambda expression be cast when supplied as a plain Delegate parameter
Tag : chash , By : Waynew
Date : March 29 2020, 07:55 AM
should help you out A lambda expression can either be converted to a delegate type or an expression tree - but it has to know which delegate type. Just knowing the signature isn't enough. For instance, suppose I have: public delegate void Action1();
public delegate void Action2();
...
Delegate x = () => Console.WriteLine("hi");
public static void Invoke(this Control control, Action action)
{
control.Invoke((Delegate) action);
}
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Is it possible to cast a delegate instance into a Lambda expression?
Tag : chash , By : barefootChild
Date : March 29 2020, 07:55 AM
it fixes the issue Everywhere that you're using the term "lambda expression" you actually mean "expression tree". A lambda expression is the bit in source code which is parameters => code
x => x * 2
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cast delegate type to Delegate and call EndInvoke
Tag : chash , By : boonchew
Date : March 29 2020, 07:55 AM
should help you out You can use reflection to access the EndInvoke() method of the delegate: using System.Reflection;
private void MonitorTasks(Delegate theDelegate, List<IAsyncResult> returnTags)
{
MethodInfo endInvoke = theDelegate.GetType().GetMethod("EndInvoke",
new Type[] { typeof(IAsyncResult) });
foreach (IAsyncResult returnTag in returnTags) {
MessageType message = (MessageType) endInvoke.Invoke(theDelegate,
new object[] { returnTag });
messages.Add(message);
}
}
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Type Cast error from lambda to delegate
Tag : chash , By : Thaweesak Suksuwan
Date : March 29 2020, 07:55 AM
around this issue New answer with edited question The problem is that your lambda expression isn't valid - you're trying to use collection initializer syntax, but your type isn't a collection. So instead of this: () => new t_user_audit { client.GetAudit(10) }
() => new List<t_user_audit> { client.GetAudit(10) }
public t_User GetAudit(int something)
lazyList = new Lazy<List<t_User>>(() => new List<t_User> { client.GetAudit(10) });
lazyList = new Lazy<List<t_User>>(() => client.GetAudit(10).ToList());
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If we can assign a Lambda expression to a delegate type .Does Lambda expression converted to a delegate internally
Date : March 29 2020, 07:55 AM
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