SendMessage

Private Declare Function SendMessage Lib "user32" Alias "Send MessageA" (ByVal hwnd As Long,ByVal wMsg As Long, ByVal wParam As Long,ByVal lParam As Long) As Long
Const TV－FIRST = ＆H1100
Const TVM－SETBKCOLOR = TV_FIRST ＋ 29

Call SendMessage(TreeView1.hwnd, TVM－SETBKCOLOR, 0, RGB(255, 0, 0))

　Const TV_FIRST = ＆H1100
Const TVM－SETITEMHEIGHT = TV_FIRST ＋ 27
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long,ByVal wMsg As Long,ByVal wParam As Long,lParam As Any) As Long

CallSendMessage(TreeView1.hwnd, TVM－SETITEMHEIGHT, 60, 0)

Option Explicit Private Type TPoint
x As Long
y As Long
End Type
Private Type TVHITTESTINFO
pt As TPoint
flags As Long
hItem As Long
End Type
Private Type TVITEM
mask As Long
HTreeItem As Long
state As Long
stateMask As Long
pszText As Long
cchTextMax As Long
iImage As Long
iSelectedImage As Long
cChildren As Long
lParam As Long
End Type
Const TV－FIRST = ＆H1100
Const TVM_HITTEST = TV－FIRST ＋ 17
Const TVM_GETITEM = TV－FIRST ＋ 12
Const TVHT－ONITEMLABEL = ＆H4
Const TVIF－TEXT = ＆H1
Const GMEM－FIXED = ＆H0
Private Declare Function Send MessageRef Lib"user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long,ByVal wParam As Long,lParam As Any) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (ByVal Destination As String，ByVal Source As Long,ByVal Length As Long)
Private Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Long, ByVal dwBytes As Long) As Long
Private Declare Function GlobalFree Lib "kernel32" (ByVal hMem As Long) As Long
Dim hItemPrv As Long
Private Sub Form_Load()
Dim ndX As Node
'加入若干Item
Set ndX = TreeView1.Nodes.Add(, , "R", "Root")
Set ndX = TreeView1.Nodes.Add("R", tvwChild, "Key1", "Node1")
Set ndX = TreeView1.Nodes.Add("Key1", tvwChild, "SubKey1", "SubNode1")
Set ndX = TreeView1.Nodes.Add("SubKey1", tvwChild, "SubKeys1", "SubNode1")
Set ndX = TreeView1.Nodes.Add("Key1", tvwChild, "SubKey2", "SubNode2")
Set ndX = TreeView1.Nodes.Add("Key1", tvwChild, "SubKey3", "SubNode3")
Set ndX = TreeView1.Nodes.Add("Key1", tvwChild, "SubKey4", "SubNode4")
End Sub
Private Sub TreeView1_MouseMove(Button As Integer, Shift As Integer, x As Single, y As Single) 
Dim ptA As TPoint
Dim tf As TVHITTESTINFO
Dim tv As TVITEM
Dim hStr As Long
Dim hItem As Long
Dim astr As String ＊ 1024
Dim bstr
On Error GoTo errLab
'获得当前光标所在的位置坐标
ptA.x = Int(x / Screen.TwipsPerPixelX)
ptA.y = Int(y / Screen.TwipsPerPixelY)
tf.pt = ptA
tf.flags = TVHT_ONITEMLABEL
'获得光标所在的Item的句柄
hItem = SendMessageRef(TreeView1.hwnd, TVM_HITTEST, 0, tf)
'如果未获得句柄或者同上一次是同一个Item的句柄则退出
If ((hItem <= 0) Or (hItem = hItemPrv)) Then Exit Sub
hItemPrv = hItem
'分配一定的内存空间用以存储Item的标题
hStr = GlobalAlloc(GMEM－FIXED, 1024)
If hStr > 0 Then
tv.mask = TVIF_TEXT 
'获取标题文本
tv.HTreeItem = hItem
'Item句柄
tv.pszText = hStr
tv.cchTextMax = 1023
'发送TVM_GETITEM获得标题文本
CallSendMessageRef(TreeView1.hwnd, TVM－GETITEM, 0, tv)
'将标题文本拷贝到字符串astr中
CopyMemory astr, hStr, 1024
bstr = Left＄(astr, (InStr(astr, Chr(0)) － 1))
TreeView1.ToolTipText = bstr
'释放分配的内存空间
GlobalFree hStr
End If
Exit Sub
errLab:
Resume Next
End Sub