WPF 创建自定义窗体

在前面的一篇博客"WPF 自定义Metro Style窗体"，展示了如何创建一个类似于Metro Style的Window，并在程序中使用。但是这个窗体不能够自由的改变大小。今天的博客中将展示如何创建一个可以通过拖拽来改变大小的Metro Style窗体。

实现思路，在Windows ControlTemplate中增加8个背景透明Rectangle，分别放置于Left, Right, Top, TopLeft, TopRight, Bottom, BottomLeft, BottomRight这8个位置，

XAML：

    <ControlTemplate x:Key="MetroWindowControlTemplate" TargetType="{x:Type Window}">
        <Border BorderThickness="1" BorderBrush="LightBlue" Background="White">
            <Grid>
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition />
                        <ColumnDefinition Width="Auto"/>
                    </Grid.ColumnDefinitions>

                    <Rectangle x:Name="MoveableRectangle" Fill="LightGray" Grid.Row="0" Grid.Column="0"/>
                    <StackPanel Grid.Row="0" Grid.Column="1" Orientation="Horizontal" Background="LightGray">
                        <Button x:Name="MinimizeButton" Style="{StaticResource WindowButtonStyle}" Content="0" />
                        <Button x:Name="RestoreButton" Style="{StaticResource WindowButtonStyle}" Content="1" />
                        <Button x:Name="CloseButton" Style="{StaticResource WindowButtonStyle}" Content="r" />
                    </StackPanel>
                    <Grid Background="{TemplateBinding Background}" Grid.Row="1" Grid.ColumnSpan="2" Margin="5,5,5,5">
                        <AdornerDecorator>
                            <ContentPresenter/>
                        </AdornerDecorator>
                    </Grid>
                </Grid>

                <Grid x:Name="ResizeGrid">
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            VerticalAlignment="Top"
                            Height="5"
                            x:Name="Top"
                            Margin="5,0,5,0" />
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            x:Name="Bottom"
                            Height="5"
                            VerticalAlignment="Bottom"
                            Margin="5,0,5,0" />
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            HorizontalAlignment="Left"
                            Margin="0,5,0,5"
                            Width="5"
                            x:Name="Left"/>
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            Margin="0,5,0,5"
                            Width="5"
                            HorizontalAlignment="Right"
                            x:Name="Right" />
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            HorizontalAlignment="Left"
                            VerticalAlignment="Bottom"
                            Width="5"
                            Height="5"
                            x:Name="BottomLeft" />
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            VerticalAlignment="Bottom"
                            Height="5"
                            Width="5"
                            HorizontalAlignment="Right"
                            x:Name="BottomRight" />
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            HorizontalAlignment="Right"
                            Width="5"
                            Height="5"
                            VerticalAlignment="Top"
                            x:Name="TopRight" />
                    <Rectangle
                            Stroke="{x:Null}"
                            Fill="Transparent"
                            HorizontalAlignment="Left"
                            Width="6"
                            VerticalAlignment="Top"
                            Height="5"
                            x:Name="TopLeft" />
                </Grid>

            </Grid>
        </Border>
    </ControlTemplate>

C#:

    ControlTemplate template = App.Current.FindResource("MetroWindowControlTemplate") as ControlTemplate;

    if(template != null)
    {
        //....

        Grid resizeGrid = template.FindName("ResizeGrid", this) as Grid;

        if(resizeGrid != null)
        {
            foreach (UIElement element in resizeGrid.Children)
            {
                Rectangle resizeRectangle = element as Rectangle;
                if (resizeRectangle != null)
                {
                    resizeRectangle.PreviewMouseDown += ResizeRectangle_PreviewMouseDown;
                    resizeRectangle.MouseMove += ResizeRectangle_MouseMove;
                }
            }
        }
    }
    
            private void ResizeRectangle_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            Rectangle rectangle = sender as Rectangle;

            if(rectangle != null)
            {
                switch(rectangle.Name)
                {
                    case "Top":
                        Cursor = Cursors.SizeNS;
                        ResizeWindow(ResizeDirection.Top);
                        break;
                    case "Bottom":
                        Cursor = Cursors.SizeNS;
                        ResizeWindow(ResizeDirection.Bottom);
                        break;
                    case "Left":
                        Cursor = Cursors.SizeWE;
                        ResizeWindow(ResizeDirection.Left);
                        break;
                    case "Right":
                        Cursor = Cursors.SizeWE;
                        ResizeWindow(ResizeDirection.Right);
                        break;
                    case "TopLeft":
                        Cursor = Cursors.SizeNWSE;
                        ResizeWindow(ResizeDirection.TopLeft);
                        break;
                    case "TopRight":
                        Cursor = Cursors.SizeNESW;
                        ResizeWindow(ResizeDirection.TopRight);
                        break;
                    case "BottomLeft":
                        Cursor = Cursors.SizeNESW;
                        ResizeWindow(ResizeDirection.BottomLeft);
                        break;
                    case "BottomRight":
                        Cursor = Cursors.SizeNWSE;
                        ResizeWindow(ResizeDirection.BottomRight);
                        break;
                    default:
                        break;
                }
            }
        }

        private void ResizeRectangle_MouseMove(object sender, MouseEventArgs e)
        {
            Rectangle rectangle = sender as Rectangle;

            if (rectangle != null)
            {
                switch (rectangle.Name)
                {
                    case "Top":
                        Cursor = Cursors.SizeNS;
                        break;
                    case "Bottom":
                        Cursor = Cursors.SizeNS;
                        break;
                    case "Left":
                        Cursor = Cursors.SizeWE;
                        break;
                    case "Right":
                        Cursor = Cursors.SizeWE;
                        break;
                    case "TopLeft":
                        Cursor = Cursors.SizeNWSE;
                        break;
                    case "TopRight":
                        Cursor = Cursors.SizeNESW;
                        break;
                    case "BottomLeft":
                        Cursor = Cursors.SizeNESW;
                        break;
                    case "BottomRight":
                        Cursor = Cursors.SizeNWSE;
                        break;
                    default:
                        break;
                }
            }
        }
        
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SendMessage(IntPtr hWnd, UInt32 msg, IntPtr wParam, IntPtr lParam);

        private void ResizeWindow(ResizeDirection direction)
        {
            SendMessage(_hwndSource.Handle, 0x112, (IntPtr)(61440 + direction), IntPtr.Zero);
        }

到此为止，就实现了一个可以拖拽改变大小的自定义窗体。

运行效果：

感谢您的阅读，代码点击这里下载。