form1.vb

清华大学出版社出版的 移动应用开发宝典 张大威（2008）的附书源代码

Imports System.Runtime.InteropServices
Imports System.Text

Public Class Form1
    Private sb As New StringBuilder(260)

    Friend Delegate Sub AddToListDelegate(ByVal hwnd As IntPtr, ByVal text As String)

    Private Sub AddToList(ByVal hwnd As IntPtr, ByVal text As String)
        Me.listBox1.Items.Add(String.Format("[{0}] - {1}", hwnd.ToInt32.ToString("X"), [text]))
    End Sub


    Private Delegate Function EnumWindowsDelegate(ByVal hwnd As IntPtr, ByVal lParam As Integer) As Integer

    Private Function EnumWindowsProc(ByVal hwnd As IntPtr, ByVal lParam As Integer) As Integer
        Dim chars As Integer = NativeMethods.GetWindowText(hwnd, Me.sb, Me.sb.Capacity)
        MyBase.Invoke(New AddToListDelegate(AddressOf Me.AddToList), New Object() {hwnd, Me.sb.ToString})
        Return -1
    End Function


    Private Class NativeMethods

        <DllImport("coredll")> _
        Friend Shared Function EnumWindows(ByVal lpEnumFunc As EnumWindowsDelegate, ByVal lParam As Integer) As <MarshalAs(UnmanagedType.Bool)> Boolean
        End Function

        <DllImport("coredll")> _
        Friend Shared Function GetWindowText(ByVal hWnd As IntPtr, ByVal lpString As StringBuilder, ByVal nMaxCount As Integer) As Integer
        End Function

    End Class

    Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button1.Click
        Me.listBox1.Items.Clear()
        NativeMethods.EnumWindows(New EnumWindowsDelegate(AddressOf Me.EnumWindowsProc), 0)
    End Sub
End Class