Question

由于SizeToContent =“WidthAndHeight”，我有一个WPF窗口随时间改变它的大小。最初WindowStartupLocation =“CenterScreen”显示窗口正确居中，之后我将其重新定位：

Private Sub Window_SizeChanged(ByVal sender As Object, ByVal e As System.Windows.SizeChangedEventArgs) Handles Me.SizeChanged
  Me.Top = (SystemParameters.WorkArea.Height - e.NewSize.Height) / 2
  Me.Left = (SystemParameters.WorkArea.Width - e.NewSize.Width) / 2
End Sub

但它会产生一个“跳跃”，因为窗口首先调整大小并居中。

有没有办法顺利完成？

Answer 1

这对我有用：

protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo)
{
    base.OnRenderSizeChanged(sizeInfo);

    //Calculate half of the offset to move the form

    if (sizeInfo.HeightChanged)
        this.Top += (sizeInfo.PreviousSize.Height - sizeInfo.NewSize.Height) / 2;

    if (sizeInfo.WidthChanged)
        this.Left += (sizeInfo.PreviousSize.Width - sizeInfo.NewSize.Width) / 2;
}

Answer 2

您可以使用TranslateTransform为位置更改设置动画，而不是直接设置Me.Top和Me.Left。

public static void MoveTo(this UIElement target, double newX, double newY)
{
    var top = Canvas.GetTop(target);
    var left = Canvas.GetLeft(target);
    TranslateTransform trans = new TranslateTransform();
    target.RenderTransform = trans;
    DoubleAnimation anim1 = new DoubleAnimation(top, newY - top, TimeSpan.FromSeconds(10));
    DoubleAnimation anim2 = new DoubleAnimation(left, newX - left, TimeSpan.FromSeconds(10));
    trans.BeginAnimation(TranslateTransform.XProperty,anim1);
    trans.BeginAnimation(TranslateTransform.YProperty,anim2);
}

代码来源：WPF. Easiest way to move Image to (X,Y) programmatically?

Answer 3

感谢您发布此信息。我的情况是我有一个对话框窗口，该对话框窗口在加载ViewModel时会调整大小，并指定其高度和宽度。我使用了您的示例，但对其进行了一些修改，以捕获所有者窗口，然后再更新。

protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo)
{
    base.OnRenderSizeChanged(sizeInfo);

    //Calculate half of the owner to move the form
    Window owner = Owner as Window;

    this.Top = (owner.Height / 2) - (this.Height / 2);
    this.Left = (owner.Width / 2) - (this.Width / 2);
}

Answer 4

private void Window_SizeChanged(object sender, SizeChangedEventArgs e)
    {
        if (e.HeightChanged)
            Top += (e.PreviousSize.Height - e.NewSize.Height) / 2;
        if (e.WidthChanged)
            Left += (e.PreviousSize.Width - e.NewSize.Width) / 2;
    }

在SizeToContent之后保持窗口居中

4 个答案: