Specifying maxlength for multiline textbox

Question

I\'m trying to use asp:

I want a way to spe

Answer 1

I tried different approaches but every one had some weak points (i.e. with cut and paste or browser compatibility). This is the solution I'm using right now:

function multilineTextBoxKeyUp(textBox, e, maxLength) {
    if (!checkSpecialKeys(e)) {
        var length = parseInt(maxLength);
        if (textBox.value.length > length) {
            textBox.value = textBox.value.substring(0, maxLength);
        }
    }
}

function multilineTextBoxKeyDown(textBox, e, maxLength) {
    var selectedText = document.selection.createRange().text;
    if (!checkSpecialKeys(e) && !e.ctrlKey && selectedText.length == 0) {
        var length = parseInt(maxLength);
        if (textBox.value.length > length - 1) {
            if (e.preventDefault) {
                e.preventDefault();
            }
            else {
                e.returnValue = false;
            }
        }
    }
}

function checkSpecialKeys(e) {
    if (e.keyCode != 8 && e.keyCode != 9 && e.keyCode != 33 && e.keyCode != 34 && e.keyCode != 35 && e.keyCode != 36 && e.keyCode != 37 && e.keyCode != 38 && e.keyCode != 39 && e.keyCode != 40) {
        return false;
    } else {
        return true;
    }
}

In this case, I'm calling multilineTextBoxKeyUp on key up and multilineTextBoxKeyDown on key down:

myTextBox.Attributes.Add("onkeyDown", "multilineTextBoxKeyDown(this, event, '" + maxLength + "');");
myTextBox.Attributes.Add("onkeyUp", "multilineTextBoxKeyUp(this, event, '" + maxLength + "');");