RichTextBox.GetCharIndexFromPosition(Point) 方法

public:
 int GetCharIndexFromPosition(System::Drawing::Point pt);

public:
 override int GetCharIndexFromPosition(System::Drawing::Point pt);

public int GetCharIndexFromPosition(System.Drawing.Point pt);

public override int GetCharIndexFromPosition(System.Drawing.Point pt);

member this.GetCharIndexFromPosition : System.Drawing.Point -> int

override this.GetCharIndexFromPosition : System.Drawing.Point -> int

Public Function GetCharIndexFromPosition (pt As Point) As Integer

Public Overrides Function GetCharIndexFromPosition (pt As Point) As Integer

參數

傳回

在指定位置的零為基礎字元索引。

範例

以下程式碼範例示範如何利用該 GetCharIndexFromPosition 方法在 Find 控制項中 RichTextBox 搜尋特定字串，並顯示該字串所在 RichTextBox 的字元索引。 範例在控制項內容中搜尋「brown」一詞，並回傳搜尋字串所在的字元索引位置。 這個範例要求你有一個表單，裡面包含 RichTextBox 一個名為 richTextBox1 控制項且包含文字的控制項。 同時也要求範例中的程式碼與事件MouseDown相連RichTextBox。

private:
   void richTextBox1_MouseDown( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
   {
      // Declare the string to search for in the control.
      String^ searchString = "brown";

      // Determine whether the user clicks the left mouse button and whether it is a double click.
      if ( e->Clicks == 1 && e->Button == ::MouseButtons::Left )
      {
         // Obtain the character index where the user clicks on the control.
         int positionToSearch = richTextBox1->GetCharIndexFromPosition( Point(e->X,e->Y) );

         // Search for the search string text within the control from the point the user clicked.
         int textLocation = richTextBox1->Find( searchString, positionToSearch, RichTextBoxFinds::None );

         // If the search string is found (value greater than -1), display the index the string was found at.
         if ( textLocation >= 0 )
            MessageBox::Show( String::Format( "The search string was found at character index {0}.", textLocation ) ); // Display a message box alerting the user that the text was not found.
         else
            MessageBox::Show( "The search string was not found within the text of the control." );
      }
   }

private void richTextBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
    // Declare the string to search for in the control.
    string searchString = "brown";

    // Determine whether the user clicks the left mouse button and whether it is a double click.
    if (e.Clicks == 1 && e.Button == MouseButtons.Left)
    {
        // Obtain the character index where the user clicks on the control.
        int positionToSearch = richTextBox1.GetCharIndexFromPosition(new Point(e.X, e.Y));
        // Search for the search string text within the control from the point the user clicked.
        int textLocation = richTextBox1.Find(searchString, positionToSearch, RichTextBoxFinds.None);

        // If the search string is found (value greater than -1), display the index the string was found at.
        if (textLocation >= 0)
            MessageBox.Show("The search string was found at character index " + textLocation.ToString() + ".");
        else
            // Display a message box alerting the user that the text was not found.
            MessageBox.Show("The search string was not found within the text of the control.");
    }
}

Private Sub richTextBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles richTextBox1.MouseDown
    ' Declare the string to search for in the control.
    Dim searchString As String = "brown"

    ' Determine whether the user clicks the left mouse button and whether it is a double click.
    If e.Clicks = 1 And e.Button = MouseButtons.Left Then
        ' Obtain the character index where the user clicks on the control.
        Dim positionToSearch As Integer = richTextBox1.GetCharIndexFromPosition(New Point(e.X, e.Y))
        ' Search for the search string text within the control from the point the user clicked.
        Dim textLocation As Integer = richTextBox1.Find(searchString, positionToSearch, RichTextBoxFinds.None)

        ' If the search string is found (value greater than -1), display the index the string was found at.
        If textLocation >= 0 Then
            MessageBox.Show(("The search string was found at character index " + textLocation.ToString() + "."))
            ' Display a message box alerting the user that the text was not found.
        Else
            MessageBox.Show("The search string was not found within the text of the control.")
        End If
    End If
End Sub

備註

此方法回傳最接近參數中位置 pt 的字元索引。 字元索引是控制項中以零為基礎的文字索引，包含空格。 你可以用這個方法，透過將滑鼠座標傳給這個方法，來判斷使用者在文字中的位置。 如果你想執行當使用者將滑鼠指標放在控制項文字中的某個字上時，這會很有用。

另請參閱

• GetLineFromCharIndex(Int32)
• GetPositionFromCharIndex(Int32)