ListView and LVM_INSERTITEM

[klaus via .NET 247]

what is wrong?

Public Declare Auto Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As IntPtr, ByVal wMsg As Long, ByVal wParam As Long, ByRef lParam As LVITEM) As Long

Public Structure LVITEM
Dim mask As Long
Dim iItem As Long
Dim iSubItem As Long
Dim State As Long
Dim stateMask As Long
Dim pszText As String
Dim cchTextMax As Long
Dim iImage As Long
Dim lParam As Long
Dim iIndent As Long
Dim iGroupId As Long
Dim cColumns As Long
Dim puColumns As Long
End Structure

Public Const LVIF_TEXT = &H1
Public Const LVIF_IMAGE = &H2
Public Const LVIF_PARAM = &H4
Public Const LVIF_STATE = &H8
Public Const LVIF_INDENT = &H10
Public Const LVIF_GROUPID = &H100
Public Const LVIF_COLUMNS = &H200

Public Const LVM_FIRST = &H1000&

Public Const LVM_INSERTITEMA = (LVM_FIRST + 7)
Public Const LVM_INSERTITEM = LVM_INSERTITEMA

Public Const LVM_GETITEMCOUNT = (LVM_FIRST + 4)

Private Sub fAddItem(ByVal sText As String, Optional ByVal lIndex As Long = 1, Optional ByVal iIcon As Long = -1, Optional ByVal iIndent As Long = 0, Optional ByVal lItemData As Long = 0)
Dim tLV As LVITEM
Dim lR As Long

tLV.pszText = sText & vbNullChar
tLV.cchTextMax = Len(sText) + 1
tLV.iImage = iIcon
tLV.iIndent = iIndent
tLV.lParam = lItemData
tLV.iItem = lIndex - 1
tLV.mask = LVIF_TEXT Or LVIF_IMAGE Or LVIF_PARAM Or LVIF_INDENT

lR = SendMessage(Me.ListView1.Handle, LVM_INSERTITEM, 0&, tLV)
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Call fAddItem("test")
End Sub

 

[Claes Bergefall]

Here are a few to start with:
1. Use Integer (32-bit) instead of Long (64-bit)
2. Add <StructLayout(LayoutKind.Sequential> to LVITEM
3. Add <MarshalAs(UnmanagedType.LPStr)> to pszText
4. Change "...Declare Auto...User32..." to "Declare Ansi...User32.dll..."
5. The puColumns member of LVITEM should be an array
6. The last three members of LVITEM are only supported
on XP. If you're going to use them why bother with ANSI?
Switch to Unicode (or remove them if you're not using them).

/claes

what is wrong?

Public Declare Auto Function SendMessage Lib "user32" Alias "SendMessageA"

(ByVal hwnd As IntPtr, ByVal wMsg As Long, ByVal wParam As Long, ByRef
lParam As LVITEM) As Long

Public Structure LVITEM
Dim mask As Long
Dim iItem As Long
Dim iSubItem As Long
Dim State As Long
Dim stateMask As Long
Dim pszText As String
Dim cchTextMax As Long
Dim iImage As Long
Dim lParam As Long
Dim iIndent As Long
Dim iGroupId As Long
Dim cColumns As Long
Dim puColumns As Long
End Structure

Public Const LVIF_TEXT = &H1
Public Const LVIF_IMAGE = &H2
Public Const LVIF_PARAM = &H4
Public Const LVIF_STATE = &H8
Public Const LVIF_INDENT = &H10
Public Const LVIF_GROUPID = &H100
Public Const LVIF_COLUMNS = &H200

Public Const LVM_FIRST = &H1000&

Public Const LVM_INSERTITEMA = (LVM_FIRST + 7)
Public Const LVM_INSERTITEM = LVM_INSERTITEMA

Public Const LVM_GETITEMCOUNT = (LVM_FIRST + 4)

Private Sub fAddItem(ByVal sText As String, Optional ByVal lIndex As

Long = 1, Optional ByVal iIcon As Long = -1, Optional ByVal iIndent As Long
= 0, Optional ByVal lItemData As Long = 0)

Dim tLV As LVITEM
Dim lR As Long

tLV.pszText = sText & vbNullChar
tLV.cchTextMax = Len(sText) + 1
tLV.iImage = iIcon
tLV.iIndent = iIndent
tLV.lParam = lItemData
tLV.iItem = lIndex - 1
tLV.mask = LVIF_TEXT Or LVIF_IMAGE Or LVIF_PARAM Or LVIF_INDENT

lR = SendMessage(Me.ListView1.Handle, LVM_INSERTITEM, 0&, tLV)
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles MyBase.Load