各位編友，那asp的問題解決了

http://geekswithblogs.net/sgreenberger/archive/2004/11/12/14871.aspx

看看這個link就行了。
C# code

protected void CheckBox_GoodReceived_Edit_CheckedChanged(object sender, EventArgs e)
{
CheckBox thisCheckBox = ((CheckBox)sender);

if (thisCheckBox.Checked)
{
((TextBox)(thisCheckBox.NamingContainer.FindControl(TextBox_GridView_GoodReceivedDate))).Text = DateTime.Now.ToString(dd-MMM-yyyy);
}
else
{
((TextBox)(thisCheckBox.NamingContainer.FindControl(TextBox_GridView_GoodReceivedDate))).Text = ;
}
}