RichTextBox.GetCharIndexFromPosition(Point) Método

Definição

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Origem:

RichTextBox.cs

Recupera o índice do caractere mais próximo ao local especificado.

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

Parâmetros

pt

Point

O local a ser pesquisado.

Retornos

Int32

O índice de caracteres baseado em zero no local especificado.

Exemplos

O exemplo de código a seguir demonstra como usar o GetCharIndexFromPosition método com o Find método para pesquisar uma cadeia de caracteres específica dentro de um RichTextBox controle e exibir o índice de caracteres em que a cadeia de caracteres encontrada está localizada dentro do RichTextBox controle. O exemplo pesquisa a palavra "marrom" dentro do conteúdo do controle e retorna a posição do índice de caracteres em que a cadeia de caracteres de pesquisa é encontrada. Este exemplo exige que você tenha um formulário que contenha um RichTextBox controle chamado richTextBox1 que contém texto. Também exige que o código no exemplo esteja conectado ao MouseDown evento do 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

Comentários

Esse método retorna o índice de caracteres mais próximo da posição especificada no pt parâmetro . O índice de caracteres é um índice de texto baseado em zero no controle, incluindo espaços. Você pode usar esse método para determinar onde no texto o usuário tem o mouse passando as coordenadas do mouse para esse método. Isso pode ser útil se você quiser executar tarefas quando o usuário colocar o ponteiro do mouse sobre uma palavra no texto do controle.

Confira também

• GetLineFromCharIndex(Int32)
• GetPositionFromCharIndex(Int32)