ASP.NET2.0使用Enter Key作为默认提交问题分析(附源码)

<form id="form1" runat="server" defaultbutton="btn1">
<div>
<asp:TextBox ID="txt" runat="server"></asp:TextBox>
<asp:Button ID="Button5" runat="server" Text="Cancel" OnClick="Button5_Click" />
<asp:Button ID="btn1" runat="server" Text="Submit" OnClick="btn1_Click" />
<asp:Panel ID="pnl1" runat="server" defaultbutton="Button1">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button1" OnClick="Button1_Click" />
</asp:Panel>
<asp:Panel ID="Panel1" runat="server" defaultbutton="Button2">
<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox4" runat="server"></asp:TextBox>
<asp:Button ID="Button2" runat="server" Text="Button2" OnClick="Button2_Click" />
</asp:Panel>
<asp:Panel ID="Panel2" runat="server" defaultbutton="Button3">
<asp:TextBox ID="TextBox5" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox6" runat="server"></asp:TextBox>
<asp:Button ID="Button3" runat="server" Text="Button3" OnClick="Button3_Click" />
</asp:Panel>
<asp:Panel ID="Panel3" runat="server" defaultbutton="Button4">
<asp:TextBox ID="TextBox7" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox8" runat="server"></asp:TextBox>
<asp:Button ID="Button4" runat="server" Text="Button4" OnClick="Button4_Click" />
</asp:Panel>
</div>
</form>
//The corresponding, sample events for the button clicks are
protected void Button1_Click(object sender, EventArgs e)
{
Response.Write(Button1.Text);
}
protected void Button2_Click(object sender, EventArgs e)
{
Response.Write(Button2.Text);
}
protected void Button3_Click(object sender, EventArgs e)
{
Response.Write(Button3.Text);
}
protected void Button4_Click(object sender, EventArgs e)
{
Response.Write(Button4.Text);
}
protected void btn1_Click(object sender, EventArgs e)
{
Response.Write(btn1.Text);
}
protected void Button5_Click(object sender, EventArgs e)
{
Response.Write(Button5.Text);
}