我需要 Shell32.dll 中 ExtractAssociatedIcon 函数的工作示例。我无法让它工作,而且我没有想法。我需要另一组关注以下代码。当表单加载时,它的图标应该设置为 Visual Studio 图标,但我得到的只是默认的系统图标。
Imports System.Runtime.InteropServices
Public Class Form1
Public Function ExtractIcon(ByVal path As String, ByVal handle As IntPtr) As Icon
Dim oResult As Icon
Dim hIcon As IntPtr
Dim iIndex As Integer
Dim oPath As New System.Text.StringBuilder(260, 260)
oPath.Append(path)
hIcon = ExtractAssociatedIcon(handle, oPath, iIndex)
'hIcon = ExtractAssociatedIcon(handle, path, iIndex)
Dim oIcon As Icon = Icon.FromHandle(hIcon)
oResult = DirectCast(oIcon.Clone, Icon)
DestroyIcon(hIcon)
Return oResult
End Function
Public Declare Auto Function ExtractAssociatedIcon Lib "shell32" ( _
ByVal hInst As IntPtr, _
<MarshalAs(UnmanagedType.LPStr)> ByVal lpIconPath As System.Text.StringBuilder, _
ByRef lpiIcon As Integer) As IntPtr
'Public Declare Auto Function ExtractAssociatedIcon Lib "shell32" ( _
' ByVal hInst As IntPtr, _
' <MarshalAs(UnmanagedType.LPStr)> ByVal lpIconPath As String, _
' ByRef lpiIcon As Integer) As IntPtr
Friend Declare Auto Function DestroyIcon Lib "user32" (<[In]()> ByVal hIcon As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'ExtractAssociatedIcon uses ExtractAssociatedIcon that is in Shell32.dll.
'This works, so why doesn't mine? What am I missing?
'Me.Icon = System.Drawing.Icon.ExtractAssociatedIcon("C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe")
Me.Icon = ExtractIcon("C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe", Me.Handle)
End Sub
End Class
已更正
<MarshalAs(UnmanagedType.LPStr)>
是问题所在。应该是LPTStr
,不是LPStr
。