Prevent the use of punctuation marks like full stops and commas in GridView Textbox

Question

Prevent the use of punctuation marks like full stops and commas in GridView Textbox

Within my GridView, there is a column that contains a textbox:

 <asp:GridView  style="width:75%;float:left"  
    ID="gvPieceOutturns" 
    ShowHeaderWhenEmpty="false"
    CssClass="tblResults" 
    runat="server" 
    OnRowDataBound="gvPieceOutturns_ItemDataBound"                          
    DataKeyField="ID" 
    AutoGenerateColumns="false"
    allowpaging="false"" />

    <Columns>
        <asp:TemplateField HeaderText="Comment" SortExpression="MemComment">
          <ItemTemplate>
            <asp:TextBox ID="txtMemComment" runat="server"></asp:TextBox>
          </ItemTemplate>
      </asp:TemplateField>
    </Columns>
</asp:GridView>

My goal is to validate the textbox so that it only allows letters and numbers, and not characters like full stops or commas.

When the user tabs off the textbox, a function is triggered:

protected void UpdateMemOutturnComment(object sender, EventArgs e)
{
    string Comment = hfMemOutturnComment.Value;
}

I am wondering how I can notify the user if they input an invalid character. Should I alert them right away or wait until they finish filling in the textbox?

javascript c#asp.net gridview

Answer 1

Answer №1

If you're looking to validate user input using regular expressions, I suggest checking out this resource on using ASP.NET RegularExpressionValidators. These validators are designed to ensure that input meets specific criteria based on a regular expression pattern. When the input doesn't comply, the user is alerted and submission is prevented. The validation typically occurs when the user moves away from the input field.

<asp:RegularExpressionValidator ID="RegularExpressionValidator1"
    ControlToValidate="TextBox1" runat="server"
    ErrorMessage="Please enter only letters and numbers" 
    ValidationExpression="^[a-zA-Z0-9]*$" />

If you're not familiar with regex, it essentially matches strings containing both lowercase and uppercase letters, as well as numbers.

Answer 2

If you're looking to validate user input using regular expressions, I suggest checking out this resource on using ASP.NET RegularExpressionValidators. These validators are designed to ensure that input meets specific criteria based on a regular expression pattern. When the input doesn't comply, the user is alerted and submission is prevented. The validation typically occurs when the user moves away from the input field.

<asp:RegularExpressionValidator ID="RegularExpressionValidator1"
    ControlToValidate="TextBox1" runat="server"
    ErrorMessage="Please enter only letters and numbers" 
    ValidationExpression="^[a-zA-Z0-9]*$" />

If you're not familiar with regex, it essentially matches strings containing both lowercase and uppercase letters, as well as numbers.

Answer 3

Answer №2

To perform validation on a TextBox, you can utilize a RegularExpressionValidator for general validation purposes. Additionally, you can trigger the onkeypress event of the TextBox for instant validation with an alert message:

<asp:TemplateField HeaderText="Comment" SortExpression="MemComment" ItemStyle-CssClass="memComment">
    <ItemTemplate>
        <asp:TextBox ID="txtMemComment" runat="server" onkeypress="ValidateMemComment(event);" />
        <asp:RegularExpressionValidator ID="revMemComment" runat="server" CssClass="validatorMemComment" ControlToValidate="txtMemComment" ValidationExpression="^[a-zA-Z0-9]*$" Text="*" ErrorMessage="Invalid character" ForeColor="Red" Display="Dynamic" />
    </ItemTemplate>
</asp:TemplateField>

The provided CSS class, .memComment, ensures that there are no line breaks between the TextBox and the validator in the cell:

.memComment
{
    white-space: nowrap;
}

The client-side onkeypress event handler would have the following structure:

<script type="text/javascript">
    function ValidateMemComment(event) {
        var code = event.which || event.keyCode;
        var isNumeric = (48 <= code && code <= 57);
        var isUpperAlpha = (65 <= code && code <= 90);
        var isLowerAlpha = (97 <= code && code <= 122);
        if (!isNumeric && !isUpperAlpha && !isLowerAlpha) {
            setTimeout(function () { alert("Invalid character!"); }, 0);
        }
    }
</script>

The setTimeout function is used here to ensure that the character is displayed before the alert message is shown.

Answer 4

To perform validation on a TextBox, you can utilize a RegularExpressionValidator for general validation purposes. Additionally, you can trigger the onkeypress event of the TextBox for instant validation with an alert message:

<asp:TemplateField HeaderText="Comment" SortExpression="MemComment" ItemStyle-CssClass="memComment">
    <ItemTemplate>
        <asp:TextBox ID="txtMemComment" runat="server" onkeypress="ValidateMemComment(event);" />
        <asp:RegularExpressionValidator ID="revMemComment" runat="server" CssClass="validatorMemComment" ControlToValidate="txtMemComment" ValidationExpression="^[a-zA-Z0-9]*$" Text="*" ErrorMessage="Invalid character" ForeColor="Red" Display="Dynamic" />
    </ItemTemplate>
</asp:TemplateField>

The provided CSS class, .memComment, ensures that there are no line breaks between the TextBox and the validator in the cell:

.memComment
{
    white-space: nowrap;
}

The client-side onkeypress event handler would have the following structure:

<script type="text/javascript">
    function ValidateMemComment(event) {
        var code = event.which || event.keyCode;
        var isNumeric = (48 <= code && code <= 57);
        var isUpperAlpha = (65 <= code && code <= 90);
        var isLowerAlpha = (97 <= code && code <= 122);
        if (!isNumeric && !isUpperAlpha && !isLowerAlpha) {
            setTimeout(function () { alert("Invalid character!"); }, 0);
        }
    }
</script>

The setTimeout function is used here to ensure that the character is displayed before the alert message is shown.

Prevent the use of punctuation marks like full stops and commas in GridView Textbox

Answer №1

Answer №2

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