[VB6]使用File Dialog選擇檔案

加入Common Dialog的控件, 成功加入後出現紅框的Icon表示成功

Microsoft Common Dialog Control 6.0

Control Object of Form

先在Form上建立CommonDialog的控件, 如未建立使用控件會跳出Variable not defined.

Button呼叫CommonDialog, 顯示FileDialog

Private Sub CTL_BTN_SEL_FILE_Click()
    With CommonDialog1
        .DialogTitle = "Select the Report File"
        .Filter = "Custom Format (*.xls)|*.xls"
        .Flags = .Flags + cdlOFNHideReadOnly
        .InitDir = specialPath("Desktop")
        .ShowOpen

        CTL_BTN_SEL_FILE.Caption = .fileName
    End With
End Sub

• Property DialogTitle As String

設定Dialog的Title

• Property Filter As String

設定檔案類型

https://docs.microsoft.com/en-us/previous-versions/visualstudio/visual-basic-6/aa238813(v=vs.60)

• Property Flags As Long

設定屬性

https://docs.microsoft.com/en-us/previous-versions/visualstudio/visual-basic-6/aa238842(v=vs.60)

• Property InitDir As String

設定初始位置

• Sub ShowOpen()

顯示File Dialog畫面

• Property FileName As String

取得選擇的File Path & Name

- 偵測是否有選取檔案

在開啟File Dialog按下取消按鈕, FileName回傳為Null String, 如再打開該路徑檔案即發生錯誤, 因為Null String.

解法可檢查FileName路徑是否存在, 之後再打開路徑檔案.

以下解法則在File Dialog判斷是否為Null String, 可省略路徑檢查的程序.

• Property CancelError As Boolean

可將CancelError設為True, 在按下取消按鈕時產生Error Event, 即如下錯誤訊息

搭配On Error GoTo即可判斷是否為按下取消按鈕

Private Sub CTL_BTN_SEL_FILE_Click()
    On Error GoTo ERROR_HANDLER


    With CommonDialog1
        .CancelError = True ' for cancel button
        .DialogTitle = "Select the Report File"
        .Filter = "UltraChip Report (*.xls)|*.xls"
        .Flags = .Flags + cdlOFNHideReadOnly
        .InitDir = specialPath("Desktop")
        .ShowOpen

        CTL_BTN_SEL_FILE.Caption = .fileName
    End With

    Exit Sub


ERROR_HANDLER:
    debugMsg (Err.Number & vbTab & Err.Description) ‘ cancel button

End Sub

Ref

http://www.svbr8.url.tw/SVBR2.0/cvb6/LMCommonDialog03.html

http://yes.nctu.edu.tw/vb/2_Ctrl/CommonDialog_ShowOpenSave_Demo.htm