防止Win32绘制经典标题栏

问题描述

我想在我的无边界表单中添加漂亮的阴影，而我发现以最小的性能损失来做到这一点的最佳方法是使用

这是我正在使用的代码：

  int v =（int）DWMNCRENDERINGPOLICY.DWMNCRP_ENABLED; 
 NativeApi.DwmSetWindowAttribute（Handle，DwmWindowAttribute.NCRENDERING_POLICY，ref v，sizeof（int））; 
 int enable = 0; 
 NativeApi.DwmSetWindowAttribute（Handle，DwmWindowAttribute.ALLOW_NCPAINT，ref enable，sizeof（int））; 
保证金=新的MARGINS（）{
 leftWidth = 0，
 topHeight = 0，
 rightWidth = 0，
 bottomHeight = 1 
}; 
 NativeApi.DwmExtendFrameIntoClientArea（Handle，ref margins）; 
  

我尝试将 ALLOW_NCPAINT 设置为1，我什至尝试在窗口收到 WM_NCPAINT 而不返回 DefWndProc 时返回0，但这没什么区别。

有没有办法解决这个奇怪的问题，同时仍然使用 DwmExtendFrameIntoClientArea ？

解决方案

非常感谢@Erik Philips，我终于通过遵循的建议。问题出在 CreateParams ：

  ///< summary> 
 ///获取定义初始窗口样式的参数。 
 ///< / summary> 
受保护的覆盖CreateParams CreateParams {
 get {
 CreateParams cp = base.CreateParams; 
 if（！DesignMode）{
 cp.ClassStyle | =（int）ClassStyle.DoubleClicks; 
 cp.Style | = unchecked（（int）（WindowStyle.Popup | WindowStyle.SystemMenu | WindowStyle.ClipChildren | WindowStyle.ClipSiblings））;; 
 cp.ExStyle | =（int）ExtendedWindowStyle.Layered; 
} 
 return cp; 
} 
} 
  

| 必须从 cp.Style 中删除​​：

 受保护的覆盖CreateParams CreateParams {
 get {
 CreateParams cp = base.CreateParams; 
 if（！DesignMode）{
 cp.ClassStyle | =（int）ClassStyle.DoubleClicks; 
 cp.Style =未选中（（int）（WindowStyle.Popup | WindowStyle.SystemMenu | WindowStyle.ClipChildren | WindowStyle.ClipSiblings））; 
 cp.ExStyle | =（int）ExtendedWindowStyle.Layered; 
} 
 return cp; 
} 
} 
  

此问题已解决，因为WinForms显然添加了 WS_BORDER 默认为类样式，即使以后将 FormBorderStyle 设置为 None 。

I wanted to add a nice shadow to my borderless form, and the best way I found to do it with minimal performance loss is to use DwmExtendFrameIntoClientArea. However, this seems to be causing Windows to draw a classic title bar over the window, but it is non-functional (ie. the glitch is merely graphical).

This is the code I am using:

int v = (int) DWMNCRENDERINGPOLICY.DWMNCRP_ENABLED;
NativeApi.DwmSetWindowAttribute(Handle, DwmWindowAttribute.NCRENDERING_POLICY, ref v, sizeof(int));
int enable = 0;
NativeApi.DwmSetWindowAttribute(Handle, DwmWindowAttribute.ALLOW_NCPAINT, ref enable, sizeof(int));
MARGINS margins = new MARGINS() {
    leftWidth = 0,
    topHeight = 0,
    rightWidth = 0,
    bottomHeight = 1
};
NativeApi.DwmExtendFrameIntoClientArea(Handle, ref margins);

I have tried setting ALLOW_NCPAINT to 1, and I even tried returning 0 when the window receives WM_NCPAINT without calling DefWndProc, but it made no difference.

Is there a way to resolve this weird issue while still using DwmExtendFrameIntoClientArea?

解决方案

Big thanks to @Erik Philips, I have finally resolved the issue by following this answer's advice. The issue was in CreateParams:

/// <summary>
/// Gets the parameters that define the initial window style.
/// </summary>
protected override CreateParams CreateParams {
    get {
        CreateParams cp = base.CreateParams;
        if (!DesignMode) {
            cp.ClassStyle |= (int) ClassStyle.DoubleClicks;
            cp.Style |= unchecked((int) (WindowStyle.Popup | WindowStyle.SystemMenu | WindowStyle.ClipChildren | WindowStyle.ClipSiblings));
            cp.ExStyle |= (int) ExtendedWindowStyle.Layered;
        }
        return cp;
    }
}

The | had to be removed from cp.Style:

protected override CreateParams CreateParams {
    get {
        CreateParams cp = base.CreateParams;
        if (!DesignMode) {
            cp.ClassStyle |= (int) ClassStyle.DoubleClicks;
            cp.Style = unchecked((int) (WindowStyle.Popup | WindowStyle.SystemMenu | WindowStyle.ClipChildren | WindowStyle.ClipSiblings));
            cp.ExStyle |= (int) ExtendedWindowStyle.Layered;
        }
        return cp;
    }
}

This solved the issue, as apparently WinForms adds WS_BORDER by default to the class style, even if FormBorderStyle is later set to None.

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