如何限制文本框中允许的字符数？

Question

<asp:TextBox ID="txtBodySMS" runat="server" Rows="10"                          
           TextMode="MultiLine" Width="100%"></asp:TextBox>

这是我的文本框.如何限制用户在其中键入的字符数？

Answer 1

MaxLength不适用于ASP.NET到Textboxes TextMode="MultiLine".一个简单的方法来做到这一点,并保持你的MultiLine标记是添加:

onkeypress="return this.value.length<=10" 

10是极限.像这样:

<asp:TextBox ID="txtBodySMS" runat="server" Rows="10" onkeypress="return this.value.length<=10" TextMode="MultiLine" Width="100%"></asp:TextBox>

Answer 2

这样做对我来说.我没有保留MultiLine属性.

<asp:TextBox ID="txtBodySMS" runat="server" Rows="10" MaxLength="2" Width="100%"></asp:TextBox>

Answer 3

的MaxLength = "的Int32"

<asp:TextBox ID="txtBodySMS" runat="server" Rows="10" MaxLength="220"                         
           TextMode="MultiLine" Width="100%"></asp:TextBox>

Answer 4

最大字符长度验证(允许最多8个字符)

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:RegularExpressionValidator Display = "Dynamic" ControlToValidate = "TextBox1" ID="RegularExpressionValidator1" ValidationExpression = "^[\s\S]{0,8}$" runat="server" ErrorMessage="Maximum 8 characters allowed."></asp:RegularExpressionValidator>

最小字符长度验证(至少需要8个字符)

<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:RegularExpressionValidator Display = "Dynamic" ControlToValidate = "TextBox2" ID="RegularExpressionValidator2" ValidationExpression = "^[\s\S]{8,}$" runat="server" ErrorMessage="Minimum 8 characters required."></asp:RegularExpressionValidator>

最小和最大字符长度验证(最少5个字符和最多8个字符)

<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>
<asp:RegularExpressionValidator Display = "Dynamic" ControlToValidate = "TextBox3" ID="RegularExpressionValidator3" ValidationExpression = "^[\s\S]{5,8}$" runat="server" ErrorMessage="Minimum 5 and Maximum 8 characters required."></asp:RegularExpressionValidator>