Question

我有一个TextBox。我希望用户能够在其中单击;当他这样做时，红色标记线应出现在最靠近咔哒位置的两个字符之间，并保留在此处。用户可以多次这样做。

我是WPF的新手，但我想，就像在Winforms中一样，我将不得不破解凌乱的OnRender方法。到目前为止，没关系。

我真正想知道的是：如何将两个最接近的字符放到点击位置？

我正要进行像素检查，但看起来很重。

Answer 1

您可以尝试： textBox.GetCharacterIndexFromPoint(point, true);

Answer 2

我发现了我想做的事情，而且比我想象的要简单得多（尽管找到实际的方式很痛苦）。

只需将此处理程序添加到文本框的SelectionChanged事件：

private void placeMarker(object sender, RoutedEventArgs e)
{
    // txt_mark is your TextBox
    int index = txt_mark.CaretIndex;
    // I don't want the user to be able to place a marker at index = 0 or after the last character
    if (txt_mark.Text.Length > first && first > 0)
    {
        Rect rect = txt_mark.GetRectFromCharacterIndex(first);

        Line line = new Line();
        // If by any chance, your textbox is in a scroll view,
        // use the scroll view's margin instead
        line.X1 = line.X2 = rect.Location.X + txt_mark.Margin.Left;
        line.Y1 = rect.Location.Y + txt_mark.Margin.Top;
        line.Y2 = rect.Bottom + txt_mark.Margin.Top;

        line.HorizontalAlignment = HorizontalAlignment.Left;
        line.VerticalAlignment = VerticalAlignment.Top;
        line.StrokeThickness = 1;
        line.Stroke = Brushes.Red;

        // grid1 or any panel you have
        grid1.Children.Add(line);
        // set the grid position of the line to txt_mark's (or the scrollview's if there is one)
        Grid.SetRow(line, Grid.GetRow(txt_mark));
        Grid.SetColumn(line, Grid.GetColumn(txt_mark));
    }
}

您可能需要添加一些字距调整，或者只是增加标记的字体大小，以免破坏可读性。

在TextBox中的字符之间绘制一条静态线

2 个答案: