VB.NET WinForm圆角矩形窗体

添加圆角矩形类

Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Runtime.InteropServices
Imports System.Text

Namespace RounRectangle
    Public Class Win32
#Region "Window Const"
        Public Const WM_ERASEBKGND As Integer = &H14
        Public Const WM_LBUTTONDOWN As Integer = &H201
        Public Const WM_LBUTTONUP As Integer = &H202
        Public Const WM_LBUTTONDBLCLK As Integer = &H203
        Public Const WM_WINDOWPOSCHANGING As Integer = &H46
        Public Const WM_PAINT As Integer = &HF
        Public Const WM_CREATE As Integer = &H1
        Public Const WM_ACTIVATE As Integer = &H6
        Public Const WM_NCCREATE As Integer = &H81
        Public Const WM_NCCALCSIZE As Integer = &H83
        Public Const WM_NCPAINT As Integer = &H85
        Public Const WM_NCACTIVATE As Integer = &H86
        Public Const WM_NCLBUTTONDOWN As Integer = &HA1
        Public Const WM_NCLBUTTONUP As Integer = &HA2
        Public Const WM_NCLBUTTONDBLCLK As Integer = &HA3
        Public Const WM_NCMOUSEMOVE As Integer = &HA0
        Public Const WM_NCHITTEST As Integer = &H84
        Public Const HTLEFT As Integer = 10
        Public Const HTRIGHT As Integer = 11
        Public Const HTTOP As Integer = 12
        Public Const HTTOPLEFT As Integer = 13
        Public Const HTTOPRIGHT As Integer = 14
        Public Const HTBOTTOM As Integer = 15
        Public Const HTBOTTOMLEFT As Integer = &H10
        Public Const HTBOTTOMRIGHT As Integer = 17
        Public Const HTCAPTION As Integer = 2
        Public Const HTCLIENT As Integer = 1
        Public Const WM_FALSE As Integer = 0
        Public Const WM_TRUE As Integer = 1
#End Region

#Region "Public extern methods"
        <DllImport("gdi32.dll")>
        Public Shared Function CreateRoundRectRgn(ByVal x1 As Integer, ByVal y1 As Integer, ByVal x2 As Integer, ByVal y2 As Integer, ByVal x3 As Integer, ByVal y3 As Integer) As Integer
        End Function

        <DllImport("user32.dll")>
        Public Shared Function SetWindowRgn(ByVal hwnd As IntPtr, ByVal hRgn As Integer, ByVal bRedraw As Boolean) As Integer
        End Function

        <DllImport("gdi32.dll", EntryPoint:="DeleteObject", CharSet:=CharSet.Ansi)>
        Public Shared Function DeleteObject(ByVal hObject As Integer) As Integer
        End Function

        <DllImport("user32.dll")>
        Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
        End Function

        <DllImport("user32.dll")>
        Public Shared Function ReleaseCapture() As Boolean
        End Function
#End Region
    End Class
End Namespace

窗体代码：创建方法

Private Sub SetFormRounRectRgn(form As Form, rgnRadius As Integer)
        Dim hRgn As Integer = 0
        hRgn = Win32.CreateRoundRectRgn(0, 0, form.Width + 1, form.Height + 1, rgnRadius, rgnRadius)
        Win32.SetWindowRgn(form.Handle, hRgn, True)
        Win32.DeleteObject(hRgn)
    End Sub

在Form_Load里面写上

SetFormRounRectRgn(Me, 40)

原文为C#编写，文章地址
https://blog.youkuaiyun.com/wangzl1163/article/details/73859048