FileDialog.FilterIndex 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

取得或設定檔案對話方塊中目前所選取之篩選條件的索引。

public:
 property int FilterIndex { int get(); void set(int value); };

public int FilterIndex { get; set; }

member this.FilterIndex : int with get, set

Public Property FilterIndex As Integer

屬性值

Int32

含有檔案對話方塊中目前所選取篩選條件之索引的值。 預設值為 1。

範例

下列程式碼範例會 OpenFileDialog 使用 的 實作 FileDialog ，並說明如何建立、設定屬性，以及顯示對話方塊。 此範例會使用 Filter 和 FilterIndex 屬性來提供使用者的篩選清單。 此範例需要放置於它的 表單 Button ，以及 System.IO 新增至它的命名空間。

private:
   void button1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      Stream^ myStream;
      OpenFileDialog^ openFileDialog1 = gcnew OpenFileDialog;

      openFileDialog1->InitialDirectory = "c:\\";
      openFileDialog1->Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
      openFileDialog1->FilterIndex = 2;
      openFileDialog1->RestoreDirectory = true;

      if ( openFileDialog1->ShowDialog() == System::Windows::Forms::DialogResult::OK )
      {
         if ( (myStream = openFileDialog1->OpenFile()) != nullptr )
         {
            // Insert code to read the stream here.
            myStream->Close();
         }
      }
   }

var fileContent = string.Empty;
var filePath = string.Empty;

using (OpenFileDialog openFileDialog = new OpenFileDialog())
{
    openFileDialog.InitialDirectory = "c:\\";
    openFileDialog.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
    openFileDialog.FilterIndex = 2;
    openFileDialog.RestoreDirectory = true;

    if (openFileDialog.ShowDialog() == DialogResult.OK)
    {
        //Get the path of specified file
        filePath = openFileDialog.FileName;

        //Read the contents of the file into a stream
        var fileStream = openFileDialog.OpenFile();

        using (StreamReader reader = new StreamReader(fileStream))
        {
            fileContent = reader.ReadToEnd();
        }
    }
}

MessageBox.Show(fileContent, "File Content at path: " + filePath, MessageBoxButtons.OK);

Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim myStream As Stream = Nothing
    Dim openFileDialog1 As New OpenFileDialog()

    openFileDialog1.InitialDirectory = "c:\"
    openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
    openFileDialog1.FilterIndex = 2
    openFileDialog1.RestoreDirectory = True

    If openFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
        Try
            myStream = openFileDialog1.OpenFile()
            If (myStream IsNot Nothing) Then
                ' Insert code to read the stream here.
            End If
        Catch Ex As Exception
            MessageBox.Show("Cannot read file from disk. Original error: " & Ex.Message)
        Finally
            ' Check this again, since we need to make sure we didn't throw an exception on open.
            If (myStream IsNot Nothing) Then
                myStream.Close()
            End If
        End Try
    End If
End Sub

備註

FilterIndex使用 屬性來設定先向使用者顯示哪一個篩選選項。 您也可以在顯示檔案對話方塊之後使用 的值 FilterIndex ，根據所選擇的篩選來執行特殊檔案作業。

注意

第一個篩選項目的索引值為 1。

另請參閱

• CheckFileExists
• Filter