RichTextBox.GetCharIndexFromPosition(Point) 方法

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

擷取最接近指定位置之字元的索引。

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

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

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

Public Overrides Function GetCharIndexFromPosition (pt As Point) As Integer

參數

pt

Point

要搜尋的位置。

傳回

Int32

指定位置處的以零為起始的字元索引。

範例

下列程式碼範例示範如何使用 GetCharIndexFromPosition 方法搭配 Find 方法來搜尋 控制項內 RichTextBox 的特定字串，並顯示找到字串位於 控制項內的 RichTextBox 字元索引。 此範例會在控制項的內容中搜尋 「brown」 一詞，並傳回找到搜尋字串的字元索引位置。 此範例會要求您有一個表單，其中包含 RichTextBox 名為 richTextBox1 的控制項，其中包含文字。 它也需要範例中的程式碼連接到 MouseDown 的事件 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

這個方法會傳回最接近參數中所指定位置的 pt 字元索引。 字元索引是控制項中文字以零起始的索引，包括空格。 您可以使用這個方法，藉由將滑鼠座標傳遞至這個方法，來判斷使用者文字中的滑鼠停留位置。 如果您想要在使用者將滑鼠指標放在控制項文字中的文字上，執行工作時，這會很有用。

另請參閱

• GetLineFromCharIndex(Int32)
• GetPositionFromCharIndex(Int32)