WinForm淡入淡出窗体的两种方式与窗体置顶-优快云博客

本文链接：https://blog.youkuaiyun.com/jclass/article/details/6103825

本文介绍了一种使用Win32 API实现窗体淡入淡出效果及将窗体置顶的方法。通过调整窗体透明度或利用特定的API函数，可以为应用程序增添更丰富的用户体验。

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1.淡入淡出窗体

注：淡入淡出窗体有两种实现方式，最简单的一种就是使用Form的Opacity属性(窗体透明度)，另外一种就是使用win32函数。

2.将窗体置顶

注：直接调用win32的User32.all包，调用SetForegroundWindow方法即可。

源代码：

Win32类：

Imports System.Runtime.InteropServices Public Class Win32 '*******************淡入淡出效果常量************************* ' 从左到右打开窗口 Public Const AW_HOR_POSITIVE As Int32 = &H1 ' 从右到左打开窗口 Public Const AW_HOR_NEGATIVE As Int32 = &H2 ' 从上到下打开窗口 Public Const AW_VER_POSITIVE As Int32 = &H4 ' 从下到上打开窗口 Public Const AW_VER_NEGATIVE As Int32 = &H8 ' 从里到外打开窗口 Public Const AW_CENTER As Int32 = &H10 Public Const AW_HIDE As Int32 = &H10000 ' 在窗体卸载时若想使用本函数就得加上此常量 Public Const AW_ACTIVATE As Int32 = &H20000 '在窗体通过本函数打开后，默认情况下会失去焦点，除非加上本常量 Public Const AW_SLIDE As Int32 = &H40000 Public Const AW_BLEND As Int32 = &H80000 '************************************************************ ' 淡入淡出效果 <DllImport("user32.dll", CharSet:=CharSet.Auto)> _ Public Shared Function AnimateWindow(ByVal hwnd As IntPtr, ByVal dwTime As Integer, ByVal dwFlags As Integer) As Boolean End Function '设置窗体透明度 <DllImport("User32.dll", EntryPoint:="SetLayeredWindowAttributes")> _ Public Shared Function SetLayeredWindowAttributes(ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As IntPtr End Function '将窗口置顶 <DllImport("User32.dll", EntryPoint:="GetForegroundWindow", CharSet:=CharSet.Auto, ExactSpelling:=True)> _ Public Shared Function GetForegroundWindow() As IntPtr End Function <DllImport("User32.dll", EntryPoint:="SetForegroundWindow", CharSet:=CharSet.Auto, ExactSpelling:=True)> _ Public Shared Function SetForegroundWindow(ByVal hWnd As IntPtr) As IntPtr End Function End Class

调用方法：

'双击将窗口置顶 Public Shared Sub SetBeforeForm(ByVal currentFormHandler As IntPtr) If currentFormHandler <> Win32.GetForegroundWindow() Then Win32.SetForegroundWindow(currentFormHandler) End If End Sub '淡入淡出窗体 Public Shared Sub FormLoad(ByVal hwnd As IntPtr) Win32.AnimateWindow(hwnd, 2000, Win32.AW_HOR_POSITIVE) End Sub Public Shared Sub FormClosed(ByVal hwnd As IntPtr) Win32.AnimateWindow(hwnd, 2000, Win32.AW_SLIDE Or Win32.AW_HIDE Or Win32.AW_BLEND) End Sub Public Shared Sub OpacityForm(ByVal newForm As System.Windows.Forms.Form) Dim i As Double For i = 0.01 To 1 Step 0.01 newForm.Opacity = i System.Windows.Forms.Application.DoEvents() System.Threading.Thread.Sleep(5) Next End Sub