Multiline texbox validation

Question

I want to validate maxlegnth of 5 characters in each row of the multiline textbox

Help me

Answer 1

using split function(both in C# and Javascript) and then check length it.

var temp = [TextFromTextBox].split('\n');
foreach(var s in temp)
{
   if(!ValidateFunction(s))
   {
      // code for show exception
   }
}

Answer 2

Here's an example: A TextArea and span to show the validation results.

<textarea cols="30" rows="10" onblur="validateRows(this)"></textarea><br/>
<span id="validationResults" style="color:red"></span>

Here's the JavaScript code to validate each row:

function validateRows(e){
   var content = e.value.split("\n");
   for(var line in content){
     var charLength = content[line].length - 1;
     var lineNumber = parseInt(line) + 1;
     if(charLength > 5){
       document.getElementById("validationResults").innerHTML += "* line " 
                         + lineNumber + " has " + charLength 
          + " characters" + "<br/>";
     }
   }
}

Answer 3

This is a C# version. Can be used either in Web applications for server side validation or Windows applications. (In Web applications for client side validation, Jose Basilio's code is appropriate)

    public static bool HasMax5CharsPerLine(TextBox target)
    {
        foreach (string Line in target.Text.Split(new char[] {'\n'}))
            if (Line.Length > 5)
                return false;
        return true;
    }