C#RichTextBox鼠标右键点击后光标移动至点击的位置

C#RichTextBox鼠标右键点击后光标移动至点击的位置

代码如下:
首先我模拟鼠标点击,光标目前应该是在我点击的位置,但是txtTextArea.SelectionStart的值还是光标上一次停留的位置的值.
我现在就是想点鼠标右键,光标就移动到我点的位置,然后我要获取这个位置在RichTextBox中的值.
请大神指点,谢谢!

 private void txtTextArea_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Right)
    {
        mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP,e.X,e.Y,0,0);
        int i = txtTextArea.SelectionStart;
    }
}

加上一个Application.DoEvents();就好了

 using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Q702922
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        [System.Runtime.InteropServices.DllImport("user32")]
        private static extern int mouse_event(int dwFlags, int dx, int dy, int cButtons, int dwExtraInfo);

        const int MOUSEEVENTF_MOVE = 0x0001;
        const int MOUSEEVENTF_LEFTDOWN = 0x0002;
        const int MOUSEEVENTF_LEFTUP = 0x0004;
        const int MOUSEEVENTF_RIGHTDOWN = 0x0008;
        const int MOUSEEVENTF_RIGHTUP = 0x0010;
        const int MOUSEEVENTF_MIDDLEDOWN = 0x0020;
        const int MOUSEEVENTF_MIDDLEUP = 0x0040;
        const int MOUSEEVENTF_ABSOLUTE = 0x8000;

        private void txtTextArea_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, e.X, e.Y, 0, 0);
                Application.DoEvents();
                int i = txtTextArea.SelectionStart;
                label1.Text = i.ToString();
            }
        }
    }
}