Example with CommandArgument & ClientClick Property ,Postback Nature of the Webpage:

Example with CommandName

Create the webpage and design the web page

• Set the following properties---- selects the Button btnAdd----Go to properties window, type Add in CommandName property

• select Button btnSubtract ----Go to properties window, type Subtract in Command Name property

•  select Button btnMultiply----Go to properties window, type Multiply in CommandName property

• select Button btnDivide ----Go to properties window, type Divide in CommandName property

•  Call the same Function F1( ) from all Buttons(i.e.,btnAdd,btnSubtract,btnMultiply,btnDivision) Command Event ---- write the following code

protected void F1(object sender, CommandEventArgs e)    {         int a,b,c=0;         a=Convert.ToInt32(txtNum1.Text);         b = Convert.ToInt32(txtNum2.Text);         if (e.CommandName == "Add")             c = a + b;         else if (e.CommandArgument == "Subtract")             c = a - b;         else if (e.CommandName == "Multiply")             c = a * b;         else if (e.CommandName == "Division")             c = a /b;         txtResult.Text = c.ToString();     }

                     

    Run the Webpage & Check

Example with CommandArgument property:-

Create the web page & Design the web page

• Select the Button btnSubmit
• Go to properties window, type Sampath in CommandArgument property
• Click on Events Button
• Double  click on CommandEvent & write the following code

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public partial class CommandArgument : System.Web.UI.Page {     protected void Page_Load(object sender, EventArgs e)     {     }     protected void btnSubmit_Command(object sender, CommandEventArgs e)     {         txtSample.Text = e.CommandArgument.ToString();     } }

Example to work with on OnClientClick Property:-

In General [client side code will be in javascript code]

• Select btnSubmit Go to Properties window
• Go to OnClientClick property
• Type the Function name F1( )
• Go to source part and Writethe following code  Before </head> tag

<script type="text/javascript"> Function F1() {         alert("Hellow Sampath"); }     </script>

PostBack nature of the web page in ASP.NET

• In general when user types the request for any web page from the browser window by typing the required URL address, we call this as 1^st request for the web page
• User may click on any Button or other Controls of the page then page request will be resubmitted as PostBack
• This result will called as PostBack request and the nature called PostBack nature of the web page
• To identify whether the request 1^st request or PostBack request, we use the property of the web page ‘Is PostBack’
• This property is a Boolean property stores false at 1^st request and true at PostBack Request

Example with PostBack nature

Create a New Web Page ,Design the Webpage   

• Goto Source & write the following code in  Page_Load Event and Button_Click Event

protected void Page_Load(object sender, EventArgs e) {         Response.Write("Welcome from PageLoad");  }  protected void btn_Click(object sender, EventArgs e)  {         Response.Write("Hellow from Button Click");  }

         Run the WebPage & Check

• If we want to display Welcome only at first Request & don’t want to run PageLoad Event code at PostBack .We Modify the Code Like:--

protected void Page_Load(object sender, EventArgs e)      {         if(IsPostBack==false)         Response.Write("Welcome from PageLoad");      }