Question

我有一个WPF应用程序，在该应用程序中，单击菜单项会打开一个窗口。如果在窗口打开时再次单击相同的菜单项，则会打开一个新窗口，但我不希望每次都打开一个新窗口。

我需要的是，如果窗口已经打开，则应该关注同一窗口而不是新窗口。

Answer 1

//First we must create a object of type the new window we want the open.
NewWindowClass newWindow;

private void OpenNewWindow() {
    //Check if the window wasn't created yet
    if (newWindow == null)
    {
        //Instantiate the object and call the Open() method 
        newWindow= new NewWindowClass();
        newWindow.Show();
        //Add a event handler to set null our window object when it will be closed
        newWindow.Closed += new EventHandler(newWindow_Closed);
    }
    //If the window was created and your window isn't active
    //we call the method Activate to call the specific window to front
    else if (newWindow != null && !newWindow.IsActive)
    {
        newWindow.Activate();
    }
}
void newWindow_Closed(object sender, EventArgs e)
{
    newWindow = null;
}

我认为这可以解决您的问题。

ATT，

Answer 2

如果您打开的窗口用作简单对话框，则可以使用以下代码

window.ShowDialog();

当对话框显示您无法按任何菜单项单位时关闭此窗口

Answer 3

像这样的蛮力方法也有效：

        bool winTest = false;

        foreach (Window w in Application.Current.Windows)
        {
            if (w is testWindow)
            {
                winTest = true;
                w.Activate();
            }
        }

        if (!winTest)
        {
            testWindow tw = new testWindow();
            tw.Show();
        }

Answer 4

您可以创建一个字段并检查它是否已设置：

private Window _dialogue = null;
private void MaekWindowButton_Click(object sender, RoutedEventArgs e)
{
    if (_dialogue == null)
    {
        Dialogue diag = new Dialogue();
        _dialogue = diag;

        diag.Closed += (s,_) => _dialogue = null; //Resets the field on close.
        diag.Show();
    }
    else
    {
        _dialogue.Activate(); //Focuses window if it exists.
    }
}

如何停止每次打开一个新窗口？

4 个答案: