gridView 编辑单元格获取单元格焦点位置（位于单元格的焦点位置）

private void Form1_Load(object sender, EventArgs e)
{
DataTable dt = new DataTable();
dt.Columns.Add("A");
dt.Columns.Add("B");
for (int i = 0; i < 20; i++)
{
dt.Rows.Add(i + 1, "测试数据0000" + i);
}
gridControl1.DataSource = dt;

}
private void txt_MouseUp(object sender, MouseEventArgs e)
{
TextEdit txt = gridView1.ActiveEditor as TextEdit;
int a = txt.SelectionStart;
MessageBox.Show("鼠标当前坐标"+a);
}