Skip to main content

Check textbox is changed or not using javascript C#.net

By

Introduction:
In my previous article I am explained about the Check uncheck all checkboxes in grid view using jquery . In this article I am going to explain about how to check whether the textbox value is changed or not using javascript and c#.net.

Explanation:
While working in a project I came to the following situation. There is a textbox in my webpage and i want to submit form only if the textbox's value has changed else i want to show some validation message. For this I have written code both in C#.net and javascript. 

I have two textboxes in form one for explain c# validation and another one for explaining the javascript validation. Below is the aspx code.
<table>
<tr>
<td>
    <asp:TextBox ID="txtName" runat="server" Text="type your name here.."></asp:TextBox>
</td>
<td>
    <asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_click" />
</td>
<td>
    <asp:Label ID="lblmsg" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
    <asp:TextBox ID="txtDescription" runat="server" Text="type description here.."></asp:TextBox>
</td>
<td>
    <asp:Button ID="Button1" runat="server" Text="Submit" OnClientClick="return validate();" />
</td>
</tr>
</table>

In code behind I am using the viewstate to store the default valuew of the textbox. On button submit I am checking whether the current value of textbox and view state value is equal. If it is equal I am returning the error message as  textbox value is not changed. After that I used return statement. return Statement is used to terminate the to come out of the function. Below is the cs code.
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        ViewState["txtValue"] = txtName.Text;
    }
}
protected void btnSubmit_click(object sender, EventArgs e)
{
    if (txtName.Text == ViewState["txtValue"].ToString())
    {
        lblmsg.Text = "Text box value is not changed..";
  return;
    }
    else
        lblmsg.Text = "Text box value is changed..";
}

Whereas in javascript to check whether the textbox value is changed or not I wrote validate function. This function will declare the textbox default value. After that it will get the current value of the textbox. After that it wil check whether the both the values are equal. Accordingly it will alert the user.return false;Is used to avoid the form submission.Below is the javascript code.
<script type="text/javascript">
    function validate() {
        var defaultval = "type description here..";
        var idval = document.getElementById('<%=txtDescription.ClientID %>').value
        if (idval == defaultval) {
            alert("Textbox value is not changed...");
            return false;
        }
        else {
            alert("Textbox value is changed...");
            return false;
        }
    }   
</script>

Do you like this article. Then comment here or share with your friends. Or like our Facebook page. Or post your comments below

Download Source Code Here
Labels:

Comments

Post a Comment

Popular posts from this blog

Code To Convert rupees(numbers) into words using C#.Net

By
Introduction: In my previous article I have explained about how to validate emailid using javascript . In this article I am going to explain about code used to convert rupees(numbers) into words using C#.Net . Explanation: For explanation purpose I have a page. It has a textbox to input the numbers. And when you click on the convert to words button then it will convert the input numbers into words and shows it in the below label. Below is the C# code used to do this functionality. public static string NumbersToWords( int inputNumber) {     int inputNo = inputNumber;     if (inputNo == 0)         return "Zero" ;     int [] numbers = new int [4];     int first = 0;     int u, h, t;     System.Text. StringBuilder sb = new System.Text. StringBuilder ();     if (inputNo < 0)     { ...
16 comments
Read More...

C# Extension Methods Example

By
In this article i am going to explain about Extension Methods  with example. Extension methods enable you to "add" methods to existing types without creating a new derived type, recompiling, or otherwise modifying the original type. Extension methods are a special kind of static method, but they are called as if they were instance methods on the extended type. For client code written in C# and Visual Basic, there is no apparent difference between calling an extension method and the methods that are actually defined in a type. If you do implement extension methods for a given type, remember the following points: An extension method will never be called if it has the same signature as a method defined in the type. Extension methods are brought into scope at the namespace level. For example, if you have multiple static classes that contain extension methods in a single namespace named Extensions, they will all be brought into scope by the using Extensions; directive. ...
Post a Comment
Read More...

Dynamically programmatically add contols at run time Asp.Net

By
Introduction: In my previous article I have explained about What is View State? How to Store and retrieve values from View State . In this article I am going to explain how to add controls programmatically on run time. Explanation: This example adds a text box and button to a Web Forms page at run time. It also dynamically binds an event handler to the button's   Click   event. The handler displays the values of the dynamically generated text box. The controls are added into a   Panel   Web server control, which acts as a placeholder. The controls are separated in the panel with line breaks (HTML <BR> elements), which are added to the panel using the   LiteralControl   control.
Post a Comment
Read More...