[英]Retrieve a ComboBox counts and items by using SendMessage API
I want to get a count and list of ComboBox
control which is not mine so that I cannot modify the code.我想获得不是我的
ComboBox
控件的计数和列表,因此我无法修改代码。
For example, controlling the target app can be done by using SendMessage
API.例如,可以使用
SendMessage
API 来控制目标应用程序。
But, how can I retrieve a whole list of the target control by hooking?但是,如何通过挂钩检索整个目标控件列表?
You can find a list of ComboBox
control messages here:您可以在此处找到
ComboBox
控件消息列表:
To get items count you need to use CB_GETCOUNT
message and to get text of an item you can use CB_GETLBTEXT
message.要获取项目计数,您需要使用
CB_GETCOUNT
消息,而要获取项目的文本,您可以使用CB_GETLBTEXT
消息。
Example例子
Here I created a ComboBoxHelper
class which you can create its instance by passing Handle
of the ComboBox
and use its properties:在这里,我创建了一个
ComboBoxHelper
类,您可以通过传递ComboBox
Handle
并使用其属性来创建其实例:
SelectedIndex
as Integer
: Returns selected index, returns -1 if no item is selected. SelectedIndex
as Integer
:返回选定的索引,如果未选择任何项目,则返回 -1。Selectedtext
as String
: Returns text of selected item, returns String.Empty
if no item is selected. Selectedtext
as String
: 返回所选项目的文本,如果没有选择项目,则返回String.Empty
。ItemsCount
as Integer
: returns count of items. ItemsCount
as Integer
:返回项目计数。Items(index)
as String
: returns text of specified item (the item at specified index) Items(index)
as String
: 返回指定项的文本(指定索引处的项)Items
as List(of String)
: returns the list of items of combo box. Items
as List(of String)
:返回组合框的项目列表。 If there is no items, it returns an empty list.Public Class ComboBoxHelper
Private hWnd As IntPtr
Const CB_GETCURSEL As Integer = &H147
Const CB_SETCURSEL As Integer = &H14E
Const CB_GETCOUNT As Integer = &H146
Const CB_GETLBTEXT As Integer = &H148
Const CB_GETLBTEXTLEN As Integer = &H149
<System.Runtime.InteropServices.DllImport("user32.dll")> _
Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, _
ByVal wParam As Integer, ByRef lParam As Integer) As IntPtr
End Function
<System.Runtime.InteropServices.DllImport("user32.dll")> _
Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, _
ByVal wParam As Integer, ByVal lParam As System.Text.StringBuilder) As IntPtr
End Function
Public Sub New(handle As IntPtr)
hWnd = handle
End Sub
Public Property SelectedIndex As Integer
Get
Return SendMessage(hWnd, CB_GETCURSEL, 0, 0).ToInt32()
End Get
Set(ByVal value As Integer)
SendMessage(hWnd, CB_SETCURSEL, value, 0).ToInt32()
End Set
End Property
Public ReadOnly Property ItemsCount As Integer
Get
Return SendMessage(hWnd, CB_GETCOUNT, 0, 0).ToInt32()
End Get
End Property
Public ReadOnly Property SelectedText As String
Get
Dim index = Me.SelectedIndex
If (Me.SelectedIndex = -1) Then
Return String.Empty
End If
Return Me.Items(index)
End Get
End Property
Public ReadOnly Property Items() As List(Of String)
Get
If (ItemsCount > 0) Then
Return Enumerable.Range(0, ItemsCount) _
.Select(Function(index) Items(index)).ToList()
Else
Return New List(Of String)
End If
End Get
End Property
Public ReadOnly Property Items(index As Integer) As String
Get
If (index < 0 OrElse index >= ItemsCount) Then
Throw New ArgumentOutOfRangeException("index")
End If
Dim length = SendMessage(hWnd, CB_GETLBTEXTLEN, index, 0).ToInt32()
Dim text As New System.Text.StringBuilder(length)
SendMessage(hWnd, CB_GETLBTEXT, index, text)
Return text.ToString()
End Get
End Property
End Class
Here is an example of usage of the class:以下是该类的使用示例:
Dim combo As New ComboBoxHelper(hWnd) 'You have hWnd
MessageBox.Show(combo.ItemsCount.ToString())
MessageBox.Show(combo.SelectedIndex.ToString())
MessageBox.Show(combo.SelectedText.ToString())
combo.Items.ForEach(Function(item) MessageBox.Show(item))
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.