//首先將窗體的 keypreview 的屬性設為 true
 
private void 窗體_KeyPress(object sender, KeyPressEventArgs e)
{
    if ( e.KeyChar == (char)13 )
    {
        this.SelectNextControl(this.ActiveControl, true, true, false, true);
    }
}
 
//或
 
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
    if ( e.KeyData == Keys.Enter )
    {
        this.SelectNextControl(this.ActiveControl, true, true, false, true);
    }
}