c# - Windows 按钮 C# 中的圆角

Question

我正在使用 visual Studio 2015。我想在 C# 中创建一个圆角窗口按钮。像这样: RoundedButton 我正在思考这段代码

[System.Runtime.InteropServices.DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
private static extern System.IntPtr CreateRoundRectRgn
(
    int nLeftRect,     // x-coordinate of upper-left corner
    int nTopRect,      // y-coordinate of upper-left corner
    int nRightRect,    // x-coordinate of lower-right corner
    int nBottomRect,   // y-coordinate of lower-right corner
    int nWidthEllipse, // height of ellipse
    int nHeightEllipse // width of ellipse
);

[System.Runtime.InteropServices.DllImport("gdi32.dll", EntryPoint = "DeleteObject")]
private static extern bool DeleteObject(System.IntPtr hObject);

private void button1_Paint(object sender, PaintEventArgs e)
{
    System.IntPtr ptr = CreateRoundRectRgn(0, 0, this.Width, this.Height, 15, 15); // _BoarderRaduis can be adjusted to your needs, try 15 to start.
    this.Region = System.Drawing.Region.FromHrgn(ptr);
    DeleteObject(ptr);
}
When I use this on `Form_paint`, it is working fine, but not working on `Button`.

当我在 Form_paint 上使用它时，它工作正常，但在 Button 上不起作用。

Answer 1

问题是您仍然从整个表单而不是按钮获取圆形区域的大小，然后您将该区域也应用到表单，而不是按钮。因此，从本质上讲，通过将区域操作代码放入按钮的 Paint 事件中，您已经更改了它发生的时间，但您没有更改什么 它正在做。试试这个:

[DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
private static extern System.IntPtr CreateRoundRectRgn
(
    int nLeftRect,     // x-coordinate of upper-left corner
    int nTopRect,      // y-coordinate of upper-left corner
    int nRightRect,    // x-coordinate of lower-right corner
    int nBottomRect,   // y-coordinate of lower-right corner
    int nWidthEllipse, // height of ellipse
    int nHeightEllipse // width of ellipse
);

[DllImport("gdi32.dll", EntryPoint = "DeleteObject")]
private static extern bool DeleteObject(System.IntPtr hObject);

private void button1_Paint(object sender, PaintEventArgs e)
{
    IntPtr ptr = CreateRoundRectRgn(0, 0, button1.Width, button1.Height, 15, 15); 
    button1.Region = Region.FromHrgn(ptr);
    DeleteObject(ptr);
}