Blocking certain charter inputs in ASP.NET can be achieved by implementing custom validation logic or

Question

Blocking certain charter inputs in ASP.NET can be achieved by implementing custom validation logic or

Here is an ASP.NET code snippet that prompts the user for input. The accompanying JavaScript ensures that the user does not leave the input field empty. Now, the goal is to prevent users from entering certain characters like (|,@,#,$) using the same JavaScript function. Any ideas on how this can be achieved?

<asp:TextBox ID="txtAccountName" runat="server" Width="100%" CssClass="input" Enabled="False" onblur="CheckTxtBox(this);"></asp:TextBox>

function CheckTxtBox(sender) {
          if (sender.value == "") {
              alert("Please enter Address 1");
              return false;
          }
      }

javascript asp.net validation

Answer 1

Answer №1

There are a couple of ways to achieve this goal:

1) Utilize the "keypress" event. Monitor for specific characters like (|,@,#,$) and prevent their entry.

2) Implement the "onblur" event. Validate the input content once the element loses focus. Display a message if the content is invalid.

Important Note

The second approach is considered superior as it can detect invalid inputs even when a user pastes content.

Implementation of First Method

 function CheckTxtBox(e) {
        var evt = (e) ? e : window.event;
        var charCode = (evt.keyCode) ? evt.keyCode : evt.which;
        if (//condition based on character codes) {
            return false;
        }
        return true;
    };

Implementation of Second Method

Within your onblur event, validate the textbox value using a regular expression.

Answer 2

There are a couple of ways to achieve this goal:

1) Utilize the "keypress" event. Monitor for specific characters like (|,@,#,$) and prevent their entry.

2) Implement the "onblur" event. Validate the input content once the element loses focus. Display a message if the content is invalid.

Important Note

The second approach is considered superior as it can detect invalid inputs even when a user pastes content.

Implementation of First Method

 function CheckTxtBox(e) {
        var evt = (e) ? e : window.event;
        var charCode = (evt.keyCode) ? evt.keyCode : evt.which;
        if (//condition based on character codes) {
            return false;
        }
        return true;
    };

Implementation of Second Method

Within your onblur event, validate the textbox value using a regular expression.

Answer 3

Answer №2

function ValidateInput(e) {
    var key;
    document.all ? key = e.keyCode : key = e.which;
    return ((key > 64 && key < 91) || (key > 96 && key < 123) || key == 8 || key == 32 || (key >= 48 && key <= 57));
}

Your ASP control example:

<asp:TextBox ID="txtAccountName" runat="server" Width="100%" CssClass="input" Enabled="False" onkeypress="return ValidateInput(event)"></asp:TextBox>

Answer 4

function ValidateInput(e) {
    var key;
    document.all ? key = e.keyCode : key = e.which;
    return ((key > 64 && key < 91) || (key > 96 && key < 123) || key == 8 || key == 32 || (key >= 48 && key <= 57));
}

Your ASP control example:

<asp:TextBox ID="txtAccountName" runat="server" Width="100%" CssClass="input" Enabled="False" onkeypress="return ValidateInput(event)"></asp:TextBox>

Answer 5

Answer №3

When it comes to validating keys or text input in edit controls, Regular Expressions come in handy. For a demonstration of how to use them, check out: where you can find examples of validation techniques.

Keep in mind that relying solely on browser-side validation is not recommended. It's crucial to perform server-side validation as well. This is important because JavaScript may be disabled in browsers, potentially allowing non-validated data to be sent to the server.

Answer 6

When it comes to validating keys or text input in edit controls, Regular Expressions come in handy. For a demonstration of how to use them, check out: where you can find examples of validation techniques.

Keep in mind that relying solely on browser-side validation is not recommended. It's crucial to perform server-side validation as well. This is important because JavaScript may be disabled in browsers, potentially allowing non-validated data to be sent to the server.

Answer 7

Answer №4

Successfully completed the task by restricting input to only uppercase letters (A-Z) and numbers (1-9). Grateful for all the assistance provided.

<asp:TextBox ID="txtAccountName" runat="server"
    Width="100%" CssClass="input" Enabled="False"  onkeypress="return isNumber(event);"></asp:TextBox>

// Javascript function to validate and prevent symbols input
function isNumber(evt) {
    evt = (evt) ? evt : window.event;
    var charCode = (evt.which) ? evt.which : evt.keyCode;
    if (charCode > 31 && (charCode < 65 || charCode > 90) && (charCode < 48 || charCode > 57)) {
        return false;
    }
    return true;
}

Answer 8

Successfully completed the task by restricting input to only uppercase letters (A-Z) and numbers (1-9). Grateful for all the assistance provided.

<asp:TextBox ID="txtAccountName" runat="server"
    Width="100%" CssClass="input" Enabled="False"  onkeypress="return isNumber(event);"></asp:TextBox>

// Javascript function to validate and prevent symbols input
function isNumber(evt) {
    evt = (evt) ? evt : window.event;
    var charCode = (evt.which) ? evt.which : evt.keyCode;
    if (charCode > 31 && (charCode < 65 || charCode > 90) && (charCode < 48 || charCode > 57)) {
        return false;
    }
    return true;
}

Blocking certain charter inputs in ASP.NET can be achieved by implementing custom validation logic or

Answer №1

Answer №2

Answer №3

Answer №4

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