Close page within Frame in a WPF

问题

I have a window and a Frame within it. in that Frame, i open many pages which i would like to close by clicking on "Close" button , the problem is the page can't see my frame i tried to write in an event a close button in a page method to execute another event in a main window because it's easy on a main window to see a frame , but it's not working. here is my code in a page

  private void closebt_MouseDown(object sender, MouseButtonEventArgs e)
     {
        var main = new MainWindow();
       main.Exitbt_PreviewKeyDown(main.Exitbt, e);

     }

and here is a code in a main window

 internal void Exitbt_PreviewKeyDown(object sender, MouseButtonEventArgs e)
      {
         ProjectorFrame.Content = "";
         MessageBox.Show("done");
      }

Although the message show but it's not close page please help me.

回答1:

I don't know why you create another MainWindow instance inside the closebt_MouseDown hander, but I hope the following code would helpful for you:

private void closebt_MouseDown(object sender, MouseButtonEventArgs e)
{
    MainWindow main = Application.Current.MainWindow as MainWindow;
    if (main != null)
    {
        main.Exitbt_PreviewKeyDown(main.Exitbt, e);
        main.Close();
    }
}

Edited:

I supposed that the main Window object of your application is MainWindow, so I thought that the previous code could get your application window close. But as you commented, Application.Current.MainWindow is different from MainWindow, and the main became null.

Therefore, I think the simple way to get the main Window object is to create the following constructor in your page class to keep the reference:

class YourPageClass
{
    public YourPageClass(MainWindow mainWindow)
    {
        main = mainWindow;
    }
    private MainWindow main;

    (snip)
}

Then, create this instance with passing main Window object:

// somewhere in MainWindow code where instantiate your page object
var page = new YourPageClass(this);

By doing that, you can get the main Window object. So now, you can close your Window object as follows:

// in YourPageClass code

private void closebt_MouseDown(object sender, MouseButtonEventArgs e)
{
    if (main != null)
    {
        main.Exitbt_PreviewKeyDown(main.Exitbt, e);
        main.Close();
    }
}

来源：https://stackoverflow.com/questions/25708309/close-page-within-frame-in-a-wpf

标签

wpf-4.0