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

参数

返回

位于指定位置的从零开始的字符索引。

示例

下面的代码示例演示如何 GetCharIndexFromPosition 将该方法与方法结合使用 Find 来搜索控件中的 RichTextBox 特定字符串，并显示找到的字符串所在的控件中的 RichTextBox 字符索引。 该示例在控件的内容中搜索单词“brown”，并返回在其中找到搜索字符串的字符索引位置。 此示例要求你有一个窗体，其中包含 RichTextBox 一个名为 richTextBox1 包含文本的控件。 它还要求示例中的代码连接到 MouseDown 该 RichTextBox事件。

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

注解

此方法返回离参数中指定的 pt 位置最近的字符索引。 字符索引是控件中文本（包括空格）的从零开始的索引。 可以使用此方法通过将鼠标坐标传递给此方法来确定用户将鼠标悬停在文本中的哪个位置。 如果用户在控件文本中将鼠标指针悬停在某个单词上时执行任务，这非常有用。

另请参阅

• GetLineFromCharIndex(Int32)
• GetPositionFromCharIndex(Int32)