WPF 下无边框窗体改变大小和移动（转）

 

WPF 下无边框窗体改变大小和移动（转）

最近一直在学习 WPF，看着别人做的WPF程序那么漂亮，眼红啊～ 很多漂亮的程序都是无边框的。于是无边框窗口操作就是最重要的了。无边框窗口的操作一直以来相关的资料就很少。WPF 下的就更少了，有的大多是无边框窗体的移动。在得到群里高人的指点，再查了一些资料之后，终于把问题解决了。

    废话不多说，直接来看看如何实现吧!其实现原理很简单：拦截并处理 Windows 消息：WM_NCHITTEST。

    WPF 处理 Windows 消息的模式和 WinForm 不一样了。Window 类里没有 WndProc 函数了，想要截取 Windows 消息必须借助 HwndSource 添加 Hook。

 

protected override void OnSourceInitialized(EventArgs e)
{
    base.OnSourceInitialized(e);
    HwndSource hwndSource = PresentationSource.FromVisual(this) as HwndSource;
    if (hwndSource != null)
    {
        hwndSource.AddHook(new HwndSourceHook(this.WndProc));
    }
}

protected virtual IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
    return IntPtr.Zero;
}

    OK，WndProc 注册完成之后就可以通过 WndProc 函数完成对Windows消息的处理了。可以发现，这里的 WndProc 和标准的 Win32 消息循环很像，只是多了一个 ref bool handled 参数，对于该参数MSDN是这样说明的：指示该消息是否已处理的值。如果该消息已处理，请将值设置为 true；否则请将其设置为 false。 在下面我们将会使用到这个参数数。

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private const int WM_NCHITTEST = 0x0084;  
private readonly int agWidth = 12; //拐角宽度  
private readonly int bThickness = 4; // 边框宽度  
private Point mousePoint = new Point(); //鼠标坐标  
   
protected virtual IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)  
{  
    switch (msg)  
    {  
        case WM_NCHITTEST:  
        this.mousePoint.X = (lParam.ToInt32() &0xFFFF);  
        this.mousePoint.Y = (lParam.ToInt32() >> 16);  
  
        测试鼠标位置#region 测试鼠标位置  
  
         // 窗口左上角  
         if (this.mousePoint.Y - this.Top <= this.agWidth   
            && this.mousePoint.X - this.Left <= this.agWidth)   
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTTOPLEFT);  
        }  
        // 窗口左下角      
         else if (this.ActualHeight + this.Top - this.mousePoint.Y <= this.agWidth   
            && this.mousePoint.X - this.Left <= this.agWidth)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTBOTTOMLEFT);  
        }  
        // 窗口右上角  
         else if (this.mousePoint.Y - this.Top <= this.agWidth   
            && this.ActualWidth + this.Left - this.mousePoint.X <= this.agWidth)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTTOPRIGHT);  
        }  
        // 窗口右下角  
         else if (this.ActualWidth + this.Left - this.mousePoint.X <= this.agWidth   
            && this.ActualHeight + this.Top - this.mousePoint.Y <= this.agWidth)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTBOTTOMRIGHT);  
        }  
        // 窗口左侧  
         else if (this.mousePoint.X - this.Left <= this.bThickness)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTLEFT);  
        }  
        // 窗口右侧  
         else if (this.ActualWidth + this.Left - this.mousePoint.X <= this.bThickness)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTRIGHT);  
        }  
        // 窗口上方  
         else if (this.mousePoint.Y - this.Top <= this.bThickness)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTTOP);  
        }  
        // 窗口下方  
         else if (this.ActualHeight + this.Top - this.mousePoint.Y <= this.bThickness)  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTBOTTOM);  
        }  
        else // 窗口移动  
        {  
            handled = true;  
            return new IntPtr((int)HitTest.HTCAPTION);  
        }  
        #endregion  
    }  
    return IntPtr.Zero;  
}  

     从上面的代码可以看出，工作原理很简单：截取 WM_NCHITTEST 消息，获得鼠标坐标，再在你希望的地方返回不同的消息以模拟鼠标的状态即可。需要注意的是，返回消息之前必须将handled 设为 true。告诉系统你已经处理过该消息，不然无效果。

    关于 HitTest 是自定义的枚举类，里面包含了鼠标的各种消息。

 

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1public enum HitTest:int  
{  
    HTERROR = -2,  
    HTTRANSPARENT = -1,  
    HTNOWHERE = 0,  
    HTCLIENT = 1,  
    HTCAPTION = 2,  
    HTSYSMENU = 3,  
    HTGROWBOX = 4,  
    HTSIZE = HTGROWBOX,  
    HTMENU = 5,  
    HTHSCROLL = 6,  
    HTVSCROLL = 7,  
    HTMINBUTTON = 8,  
    HTMAXBUTTON = 9,  
    HTLEFT = 10,  
    HTRIGHT = 11,  
    HTTOP = 12,  
    HTTOPLEFT = 13,  
    HTTOPRIGHT = 14,  
    HTBOTTOM = 15,  
    HTBOTTOMLEFT = 16,  
    HTBOTTOMRIGHT = 17,  
    HTBORDER = 18,  
    HTREDUCE = HTMINBUTTON,  
    HTZOOM = HTMAXBUTTON,  
    HTSIZEFIRST = HTLEFT,  
    HTSIZELAST = HTBOTTOMRIGHT,  
    HTOBJECT = 19,  
    HTCLOSE = 20,  
    HTHELP = 21,  
}