CheckBox 全选和反选

protected void chkSelectAll_CheckedChanged(object sender, EventArgs e)
    {
        for (int i = 0; i <= GridView1.Rows.Count - 1; i++)
        {
            ((CheckBox)GridView1.Rows[i].FindControl("chkSelected")).Checked = this.chkSelectAll.Checked;
        }
    }