限制TextBox Visual Studio C＃的内容

Question

I am trying to limit the user input so that users can only enter digits to a textBox named OrderID and only input letters to a textBox named CustomerName.

Is it possible to do this in Visual Studio Web Application Forms? Coding in C#. If so, how can I this be done?

I must also deal with exceptions if a user tries to enter an invalid datatype once the above is implemented.

How can this be done? Any help is much appreciated! :)

Answer 1

use regular expressions
for text use it- ^[a-zA-Z]*$ .
use CompareValidator, for digits

<asp:TextBox ID="txt" runat="server />
<asp:CompareValidator ID="cv" runat="server" ControlToValidate="txt" Type="Integer"
   Operator="DataTypeCheck" ErrorMessage="Value must be an integer!" />

Answer 2

You can achieve this by extending the TextBox class, like this way: I have already done this for one project.

Add this line in AssemblyInfo.cs class:

[assembly: WebResource("Web.Controls.Javascript.NumberBox.js", "text/javascript")]

C# Class:

public sealed class NumberBox : TextBox
{
    protected override void OnPreRender(EventArgs e)
    {
        RegisterIncludeScripts();

        this.Attributes.Add("onkeydown", "return NumberBox_KeyDown(this, event);");
        this.Attributes.Add("onkeyup", "return NumberBox_KeyUp(this, event);");
        this.Attributes.Add("onblur", "NumberBox_Blur(this);");
        this.Attributes.Add("onpaste", "NumberBox_Paste(this);");

        base.OnPreRender(e);
    }

    private void RegisterIncludeScripts()
    {
        this.Page.ClientScript.RegisterClientScriptResource(typeof(TextBox), "Web.Controls.Javascript.NumberBox.js");
    }

    public int Number
    {
        get
        {
            if (this.Text.Equals(String.Empty)) return -1;
            else return Convert.ToInt32(this.Text);
        }
    }
}

JavaScript:

function NumberBox_KeyDown(control, e) {
    var keynum = GetKeystroke(e);

    if (IsFuncKey(keynum))
        return true;

    var keychar = String.fromCharCode(keynum);

    if (NumberBox_IsExceedingLimit(control, control.value + keychar))
        return false;

    if (keynum >= 96 && keynum <= 105)
        return true;

    var numcheck = /\d/;
    return numcheck.test(keychar);
}

function NumberBox_KeyUp(control, e) {
    var keynum = GetKeystroke(e);

    if (IsFuncKey(keynum))
        return true;

    control.value = control.value.replace(/[^0-9 ]/g, '');
}

function NumberBox_Paste(control) {
    control.value = control.value.replace(/[^0-9 ]/g, '');
    if (NumberBox_IsExceedingLimit(control)) {
        control.value = control.value.substring(0, control.value.length - 1);
    }
}

function NumberBox_Blur(control) {
    control.value = control.value.replace(/[^0-9 ]/g, '');
    if (NumberBox_IsExceedingLimit(control)) {
        control.value = control.value.substring(0, control.value.length - 1);
    }
}

function NumberBox_IsExceedingLimit(control, value) {
    var maxValue = control.attributes["maxValue"].value;
    var value = String(value);

    if (value.length > maxValue) {
        return true;
    }
    return false;
}

function NumberBox_IsExceedingLimit_IsInsideBoundary(control, value) {
    var minValue = control.attributes["minValue"].value;
    var maxValue = control.attributes["maxValue"].value;
    var value = String(value);

    if (value.length >= minValue && value.length <= maxValue) {
        return true;
    }
    return false;
}

Answer 3

You can use compare validator, here is my sample how to check datatype:

            <asp:TextBox ID="TextBoxServiceDate" CssClass="OneColumnText" runat="server" Text='<%# Bind("ServiceDate","{0:d}")  %>'
                ValidationGroup="update"></asp:TextBox>*
            <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ControlToValidate="TextBoxServiceDate"
                Display="None" ErrorMessage="<% $resources:AppResource,ServiceDateRequired %>"
                ValidationGroup="update"></asp:RequiredFieldValidator>
            <asp:CompareValidator ID="CompareValidatorQuantity" runat="server" ControlToValidate="TextBoxServiceDate" ValidationGroup="update" Display="None"
                Type="Date" Operator="DataTypeCheck" ErrorMessage='<% $Resources:AppResource,NotValidDateTime %>' />
            <br />

In this sample there are two validators. First is used only to check required field, second is used to check datatype, in this case Date. Of course you can also check digits if required, you can also use custom validator for more complex reqirements. This would look something like this:

    <asp:CustomValidator ID="CustomValidatorDate1" runat="server" ControlToValidate="DateFromTextBox"
        ErrorMessage='<% $resources:AppResource,NotValidDateTime %>' Display="Dynamic"
        onservervalidate="CustomValidatorDate1_ServerValidate"></asp:CustomValidator>

And the handler...

    protected void CustomValidatorDate1_ServerValidate(object source, ServerValidateEventArgs args)
    {
        if (!string.IsNullOrEmpty(args.Value))
        {
            DateTime d = new DateTime();
            if (!DateTime.TryParse(args.Value, out d))
            {
                args.IsValid = false;
            }
            else
            {
                args.IsValid = true;
            }
        }
        else
        {
            args.IsValid = true;
        }
    }

To display validation message you can use dynamic mode or just validation summary like this:

<asp:ValidationSummary ID="ValidationSummary1" runat="server" ValidationGroup="Insert" />