Tips for Asp.Net

How to assign RequiredFiled Validator for DropDownList in Asp.Net

Ans:

      
 <form id="form1" runat="server">
        <div>
            Select Gender :
            <asp:DropDownList runat="server" ID="ddlList">
                <asp:ListItem Text="Select" Value="0"></asp:ListItem>
                <asp:ListItem Text="Male" Value="1"></asp:ListItem>
                <asp:ListItem Text="Female" Value="2"></asp:ListItem>
            </asp:DropDownList>
            <asp:RequiredFieldValidator runat="server" ID="rfv" ControlToValidate="ddlList" ForeColor="Red" InitialValue="0" ErrorMessage="Please Select Gender"></asp:RequiredFieldValidator><br />
        <asp:Button  runat="server" ID="btnsubmit" Text="Submit" />
        </div>
    </form>
 

Output:

---

How to add items to DropDownList through .Cs file

Ans:  In .aspx file

  
 <form id="form1" runat="server">
        <div>
            Select Gender :
            <asp:DropDownList runat="server" ID="DropDownList1">             
            </asp:DropDownList>
            <asp:RequiredFieldValidator runat="server" ID="RequiredFieldValidator1" ControlToValidate="DropDownList1" ForeColor="Red" InitialValue="0" ErrorMessage="Please Select Gender"></asp:RequiredFieldValidator><br />
        <asp:Button  runat="server" ID="Button1" Text="Submit" />
        </div>
    </form>

     In .Cs file 

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            ListItem item1 = new ListItem("Select", "0");
            ListItem item2 = new ListItem("Male", "1");
            ListItem item3 = new ListItem("Female", "2");

            DropDownList1.Items.Insert(0, item1);
            DropDownList1.Items.Insert(1, item2);
            DropDownList1.Items.Insert(2, item3);
        }

    }

Output:

---

How to Get DataKeyNames from GridView using RowUpdating Event and Button Click Event of Gridview

Ans:

In RowUpdating Event of GridView

      
protected void Gridview1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        //Suppose if DataKeyName is type Integer
        Int32 DataKeyInt = Convert.ToInt32(Gridview1.DataKeys[e.RowIndex].Value.ToString());

        //Suppose if DataKeyName is type String

        String DataKeyString = Gridview1.DataKeys[e.RowIndex].Value.ToString();
    }

In Button Click Event in GridView

      
protected void Button1_Click(object sender, EventArgs e)
    {
        Button btn = (Button)sender;
        GridViewRow row = (GridViewRow)btn.NamingContainer;
        //Suppose if DataKeyName is type Integer
        Int32 DataKeyInt = Convert.ToInt32(Gridview1.DataKeys[row.RowIndex].Value.ToString());

        //Suppose if DataKeyName is type String

        String DataKeyString = Gridview1.DataKeys[row.RowIndex].Value.ToString();

    }

  

---

How to find Control in GridView Using RowUpdating Event and RowDataBound Event

Ans:

In RowUpdating Event

      
protected void Gridview1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        //Suppose if we want to find TextBox Control from GridView
        TextBox txt = (TextBox)Gridview1.Rows[e.RowIndex].FindControl("txtboxID");
        string textboxvalue = txt.Text;

        //Suppose if we want to find Label Control from GridView
        Label lbl = (Label)Gridview1.Rows[e.RowIndex].FindControl("lblID");
        string lblvalue = lbl.Text;

       
    }

In RowDataBound Event

      
protected void Gridview1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        //Suppose if we want to find TextBox Control from GridView
        TextBox txt = Gridview1.FindControl("txtID") as TextBox;
        string textboxvalue = txt.Text;

        //Suppose if we want to find Label Control from GridView
        Label lbl = Gridview1.FindControl("lblID") as Label;
        string lblvalue = lbl.Text;
    }