Handling event of user control in its holding page

问题:

I am looking for a solution for following situation.

In my application i had a page say page1 and i placed a user control inside the page1. My requirement is i need to get the click event of button used in user control on page1's code behind. How i can achieve the same in windows phone / silverlight.

回答1:

1. The first and the right way:

(If you are aware of MVVM pattern) would be for you control, say MyControl, to expose DependencyProperty of type ICommand, named e.g. MyControlButtonClickCommand.

Xaml:

<UserControl>
    <Button Command={Binding MyControlButtonClickCommand, Source={RelativeSource Self}} />
</UserControl>  

Code-Behind:

public ICommand MyControlButtonClickCommand
{
    get { return (ICommand)GetValue(MyControlButtonClickCommandProperty); }
    set { SetValue(MyControlButtonClickCommandProperty, value); }
}

public static readonly DependencyProperty MyControlButtonClickCommandProperty =
        DependencyProperty.Register("MyControlButtonClickCommand", typeof(ICommand), typeof(MyControl), new PropertyMetadata(null));  

You'd use you UserControl as follows:

<phone:PhoneApplicationPage>

    <namespace:MyControl MyControlButtonClickCommand="{Binding ControlButtonCommand}" />

</phone:PhoneApplicationPage>

Where ControlButtonCommand is a property of a ViewModel (your custom object), living in a DataContext of your Page.

2. There is also a simpler and dirtier way which I discourage you to go:

Just like you expose MyControlButtonClickCommand dependency property and instead of exposing it, you can expose an event MyControlButtonClick and in the Page's xaml subscribe to it. Internally in your UserControl's code you should subscribe to it's button's Click event and fire its own MyControlButtonClick event.

Hope this will help you.

回答2:

There are two ways to do it, simplest would be double click the button on the presentation layout.

Or

in XML add onCLick= doing this would popup the menu to select new event. click on that and you event for button click should be there on the code behind.

<button name="b1" onClick="button1_Click()"/> <!--this is what ur XAML will look like -->

to handle the button click

private void button1_Click(object sender, RoutedEventArgs e)
{
    // Handle the click event here

}

回答3:

For the UserControl you can create an interface which your Page1.xaml.cs will implement.

public partial Class SomeControl : UserControl
{
    private OnButtonClick button_click;

    public interface OnButtonClick
    {
        void someMethod();   // generic, you can also use parameters to pass objects!!
    }

    // Used to add interface to dynamic controls
    public void addButtonClickInterface(OnButtonClick button_click)
    {
        this.button_click = button_click;
    }

    // Buttons UserControlled Click
    private void ButtonClick(object sender, RoutedEventArgs e)
    {
        if(button_click != null)
        {
            button_click.someMethod();  
        }
    }

}

Here is how to implement it and use it.

public partial class Page1 : PhoneApplicationPage, SomeControl.OnButtonClick
{

    public Page1()
    {
        InitializeComponent()

        // for a new Control
        SomeControl cntrl = new SomeControl();
        cntrl.addButtonClickInterface(this);

        // or for a control in your xaml
        someControl.addButtonClickInterface(this);
    }

    public void someMethod()
    {
        // Here is where your button will trigger!!
    }

}