如何解决如何使用 VB.NET 在 Windows 10 上的 Windows 窗体标题栏中绘制自定义按钮?
我使用 VB.NET 和 Windows 窗体搜索以在窗体的标题栏中显示自定义按钮。
我已阅读并复制了 How to draw custom button in Window Titlebar with Windows Forms? 和 Adding a custom button in title bar VB.NET 的代码
这 2 个问答的问题在于它们很旧,无法在我打开 Windows 10 的 PC 上运行。
当我使用以下代码时
Public Class Form1
Private Const WM_PAINT As Integer = &HF
Private Const WM_NCPAINT As Integer = &H85
Private Const WM_ACTIVATE As Integer = &H86
Private oButtonState = ButtonState.Normal
Private oButtonPos = New Rectangle()
Declare Function GetWindowDC Lib "user32" (ByVal hwnd As IntPtr) As IntPtr
Declare Function GetWindowRect Lib "user32" (ByVal hWnd As IntPtr,ByRef lpRect As Rectangle) As Boolean
Declare Function ReleaseDC Lib "user32" (ByVal hWnd As IntPtr,ByVal prmlngHDc As IntPtr) As <Runtime.InteropServices.MarshalAs(Runtime.InteropServices.UnmanagedType.Bool)> Boolean
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
Dim x As Integer
Dim y As Integer
Dim wRect As Rectangle = New Rectangle()
Select Case m.Msg
Case WM_NCPAINT
MyBase.WndProc(m)
DrawButton(m.HWnd)
m.Result = IntPtr.Zero
Case WM_PAINT
MyBase.WndProc(m)
DrawButton(m.HWnd)
m.Result = IntPtr.Zero
Case WM_ACTIVATE
MyBase.WndProc(m)
DrawButton(m.HWnd)
Case Else
MyBase.WndProc(m)
End Select
End Sub
Private Sub DrawButton(hwnd As IntPtr)
Dim hDC = GetWindowDC(hwnd)
Dim x As Integer
Dim y As Integer
Using g As Graphics = Graphics.FromHdc(hDC)
Dim iCaptionHeight = Bounds.Height - Me.ClientRectangle.Height
Dim oButtonSize As Size = SystemInformation.CaptionButtonSize
x = Bounds.Width - 4 * oButtonSize.Width
y = (iCaptionHeight - oButtonSize.Height) / 2
oButtonPos.Location = New Point(x,y)
'// Work out color
Dim color As Brush
If oButtonState = ButtonState.Pushed Then
color = Brushes.LightGreen
Else
color = Brushes.Red
End If
'// Draw our "button"
g.FillRectangle(color,x,y,oButtonSize.Width,oButtonSize.Height)
End Using
ReleaseDC(hwnd,hDC)
End Sub
End Class
当我在 Visual Studio 2019 的调试模式下运行此代码时,自定义按钮永远不会显示!
当我像这样更改 WM_NCPAINT 代码(所有行都被注释)
Case WM_NCPAINT
'MyBase.WndProc(m)
'DrawButton(m.HWnd)
'm.Result = IntPtr.Zero
我得到以下结果
如果我激活 VS Studio 2019 并返回到我的应用程序,我可以看到以下结果。
我要说明的是第一个带有红色矩形的 PrintScreen。最后一个 PrintScreen 不正确,因为 Minimize
和 Close
按钮具有不同的样式!
我的代码中有什么错误?
感谢您的帮助。
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