DevExpress XtraEditors波斯语RTL模式下光标过小问题求助

针对波斯语RTL场景下TextEdit、ComboBoxEdit、LookUpEdit等控件在空白或文本开头时光标极小的问题，可通过以下几种方案解决：

方案1：自定义绘制光标 #

通过控件的CustomDraw事件手动调整光标尺寸，适用于单个或少量控件的场景：

private void TextEdit_CustomDraw(object sender, DevExpress.XtraEditors.CustomDrawEventArgs e)
{
    var editor = sender as TextEdit;
    if (editor == null || editor.RightToLeft != RightToLeft.Yes) return;

    var viewInfo = editor.GetViewInfo() as TextEditViewInfo;
    if (viewInfo == null) return;

    // 判断是否处于空白或文本开头状态
    if (string.IsNullOrEmpty(viewInfo.Text) || viewInfo.SelectionStart == 0)
    {
        // 重新绘制宽光标
        var cursorRect = viewInfo.CursorRectangle;
        cursorRect.Width = 3; // 设置合适的光标宽度
        e.Graphics.FillRectangle(SystemBrushes.IBeam, cursorRect);
        e.Handled = true;
    }
}

注：ComboBoxEdit和LookUpEdit可复用类似逻辑，只需将TextEdit和TextEditViewInfo替换为对应控件的类型。

方案2：通过ViewInfo强制调整光标尺寸 #

利用控件的GotFocus事件，通过反射修改ViewInfo中的光标矩形属性，适合批量处理控件：

private void BaseEdit_GotFocus(object sender, EventArgs e)
{
    var editor = sender as BaseEdit;
    if (editor == null || editor.RightToLeft != RightToLeft.Yes) return;

    var viewInfo = editor.GetViewInfo();
    var cursorProp = viewInfo.GetType().GetProperty(
        "CursorRectangle", 
        System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic
    );

    if (cursorProp == null) return;

    var cursorRect = (Rectangle)cursorProp.GetValue(viewInfo);
    // 仅在光标宽度异常时调整
    if (cursorRect.Width < 2)
    {
        cursorRect.Width = 3;
        cursorProp.SetValue(viewInfo, cursorRect);
        editor.Refresh();
    }
}

只需将所有目标控件的GotFocus事件绑定到该方法即可批量生效。

方案3：升级DevExpress版本 #

该问题属于DevExpress RTL渲染的已知bug，官方在后续版本中已修复。若项目允许，直接升级到最新稳定版（建议v20.2及以上）即可彻底解决，无需自定义代码。

方案4：自定义控件Renderer #

创建自定义的EditorRenderer，重写光标绘制逻辑，适用于全局统一处理的场景：

public class CustomTextEditRenderer : TextEditRenderer
{
    protected override void DrawCursor(GraphicsCache cache, Rectangle cursorRect, BaseEditViewInfo viewInfo)
    {
        if (viewInfo.RightToLeft == RightToLeft.Yes && (string.IsNullOrEmpty(viewInfo.Text) || viewInfo.SelectionStart == 0))
        {
            cursorRect.Width = 3;
        }
        base.DrawCursor(cache, cursorRect, viewInfo);
    }
}

// 在项目启动时注册Renderer
static Program()
{
    EditorRendererRepository.Default.RegisterRenderer(typeof(TextEdit), new CustomTextEditRenderer());
}

内容的提问来源于stack exchange，提问作者Reza Hosseini