编译出错?????
private void btn_Return_Click(object sender, System.EventArgs e)
{
foreach (Control c in this.Form.Controls)
{
if (c.GetType() == typeof(TextBox)) (c as TextBox).Text = " ";
}
}

编译是出现:不可访问“System.Web.UI.Page.Form”，因为它受保护级别限制

[解决办法]
foreach(Control ct in Page.Controls)
{
foreach(Control ct1 in ct.Controls)
{
if(ct1.GetType().ToString()== "System.Web.UI.WebControls.CheckBox ".ToString())
{
((CheckBox)ct1).Checked=false;
}
}
}