這個演示，在輸入時，是不需要與服務端交互，只有全部輸入完畢之后，用戶點銨鈕才進行驗證。因此在這里，寫Javascript來實現即可。

js:

復制代碼 代碼如下:

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

Html code:

復制代碼 代碼如下:

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