asp.net中C# WinForm 判断窗体控件是否修改过

interface IModify
{
bool IsModified { get; }
}

class TextBoxEx : TextBox, IModify
{
private bool isModified = false;

public bool IsModified
{
get { return isModified; }
}

protected override void OnTextChanged(EventArgs e)
{
this.isModified = true;
base.OnTextChanged(e);
}
}

private void button1_Click(object sender, EventArgs e)
{
var b = IsModify(this);
Text = b.ToString();
}

private bool IsModify(Control ctrl)
{
foreach (Control control in ctrl.Controls)
{
if (control.Controls.Count > 0)
return IsModify(control);
if (control is IModify)
{
if (((IModify)control).IsModified)
return true;
}
}