How to make MarkupExtenstion for button click event in WPF 4.5?

Question

I want to create a MarkupExtension to provide support for a button event. I have an article for PreviewKeyDown here . I tried changing it for Click, but could not do it because it throws an exception

Please suggest how to implement this.

Answer 1

It looks like it is trying to use MethodInfo as EventInfo , the return target property may be MethodInfo or EventInfo , you will need to check this before creating the delegate

try it

  public class Call : MarkupExtension { public string ActionName { get; set; } public Call(string actionName) { ActionName = actionName; } public override object ProvideValue(IServiceProvider serviceProvider) { IProvideValueTarget targetProvider = serviceProvider .GetService(typeof(IProvideValueTarget)) as IProvideValueTarget; if (targetProvider == null) throw new InvalidOperationException(@"The CallAction extension can't retrieved the IProvideValueTarget service."); var target = targetProvider.TargetObject as FrameworkElement; if (target == null) throw new InvalidOperationException(@"The CallAction extension can only be used on a FrameworkElement."); if (targetProvider.TargetProperty is MethodInfo) { var targetEventAddMethod = targetProvider.TargetProperty as MethodInfo; if (targetEventAddMethod != null) { ParameterInfo[] pars = targetEventAddMethod.GetParameters(); Type delegateType = pars[1].ParameterType; MethodInfo methodInfo = this.GetType().GetMethod("MyProxyHandler", BindingFlags.NonPublic | BindingFlags.Instance); return Delegate.CreateDelegate(delegateType, this, methodInfo); ; } } else if (targetProvider.TargetProperty is EventInfo) { var targetEventInfo = targetProvider.TargetProperty as EventInfo; if (targetEventInfo != null) { Type delegateType = targetEventInfo.EventHandlerType; MethodInfo methodInfo = this.GetType().GetMethod("MyProxyHandler", BindingFlags.NonPublic | BindingFlags.Instance); return Delegate.CreateDelegate(delegateType, this, methodInfo); } } return null; } void MyProxyHandler(object sender, EventArgs e) { FrameworkElement target = sender as FrameworkElement; if (target == null) return; var dataContext = target.DataContext; if (dataContext == null) return; //get the method on the datacontext from its name MethodInfo methodInfo = dataContext.GetType() .GetMethod(ActionName, BindingFlags.Public | BindingFlags.Instance); methodInfo.Invoke(dataContext, null); } }