这个演示，在输入时，是不需要与服务端交互，只有全部输入完毕之后，用户点铵钮才进行验证。因此在这里，写Javascript来实现即可。

js:

复制代码 代码如下:

<script type="text/javascript">
        function JumpToNextTextBox(currentTxtBox, nextTextBoxID) {
            if (currentTxtBox.value.length >= 5) {
                document.getElementById(nextTextBoxID).focus();
            }
        }
    </script>

Html code:

复制代码 代码如下:

  License Key:
            <asp:TextBox ID="Number1" runat="server" onkeyup="JumpToNextTextBox(this, 'Number2')" Width="65"></asp:TextBox>
            -
        <asp:TextBox ID="Number2" runat="server" onkeyup="JumpToNextTextBox(this, 'Number3')" Width="65"></asp:TextBox>
            -
        <asp:TextBox ID="Number3" runat="server" onkeyup="JumpToNextTextBox(this, 'Number4')" Width="65"></asp:TextBox>
            -
        <asp:TextBox ID="Number4" runat="server" onkeyup="JumpToNextTextBox(this, 'Number5')" Width="65"></asp:TextBox>
            -
        <asp:TextBox ID="Number5" runat="server" MaxLength ="5" Width="65"></asp:TextBox>