问题描述
我有一个带有搜索屏幕的VB6应用程序.在搜索中,我有9个组合框.一些组合框只有几个项目,但有些则有数百个项目.填充数据需要很长时间(几秒钟).
I have a VB6 application with a search screen. On the search, I have 9 combo boxes. Some of the combo boxes only have a couple items, but some have a couple hundred items. It takes a long time (couple of seconds) to populate the data.
每个组合框的配置都相同:排序= False,样式= 2-下拉列表
Each combo box is configured the same: Sorted = False, Style = 2 - Dropdown List
3个组合框的项目少于20个.1件商品有130件.4个有大约250个项目1个有将近700个项目.
3 of the combo boxes have less that 20 items.1 has 130 items.4 have approximately 250 items1 has almost 700 items.
我用相似的代码填充所有九个组合框.
I fill all nine combo boxes with similar code.
While Not RS.EOF
cmbX.List(i) = RS("Description")
cmbX.ItemData(i) = RS("Id")
i = i + 1
RS.MoveNext
Wend
我尝试设置Visible = False,但对性能没有影响.
I tried setting Visible = False but it had no effect on performance.
是否有另一种方法来填充组合框,该组合框的性能将比现有方法更好?
推荐答案
您可以尝试以下方法.根据此帖子,您可以节省60%的开销通过使用Windows API函数而不是通常的AddItem方法来填充组合框:
Here is something you can try. According to this post you can shave about 60% off your overhead by using a Windows API function to populate the combo box, instead of the usual AddItem method:
Private Const CB_ERR As Long = -1
Private Const CB_ADDSTRING As Long = &H143
Private Const CB_RESETCONTENT As Long = &H14B
Private Const CB_SETITEMDATA As Long = &H151
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
Public Sub AddItem(cmb As ComboBox, Text As Variant, Optional ItemData As Long)
Dim l As Long
Dim s As String
If VarType(Text) = vbString Then
s = Text
Else
s = Trim$(Str$(Text))
End If
l = SendMessage(cmb.hwnd, CB_ADDSTRING, 0&, ByVal s)
If l <> CB_ERR Then
SendMessage cmb.hwnd, CB_SETITEMDATA, l, ByVal ItemData
End If
End Sub
Public Sub Clear(cmb As ComboBox)
SendMessage cmb.hwnd, CB_RESETCONTENT, 0, 0&
End Sub
通过省略函数调用,而直接调用API函数,您也许可以节省更多的钱.
You might be able to shave a little more off by omitting the function call, and just calling the API function directly.
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