Thursday, October 27, 2011

GRIDVIEW EVENTS IN ASP.NET with C#

GridView is the most reused tool in ASP.NET. This gridview contains 7 major events which are always used in every situation.
  1. grdGroups_PageIndexChanging
  2. grdGroups_RowDeleting
  3. grdGroups_RowEditing
  4. grdGroups_RowCancelingEdit
  5. grdGroups_RowUpdating
  6. grdGroups_RowCommand
  7. grdGroups_Sorting



All the above events are web server events which are coded as below

//This PageIndexChanging event is used for navigating from one page to another page. Here page means set //of records. Each page contains count of records. The page size is defined in code behind.

protected void grdGroups_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            try
            {
                grdGroups.PageIndex = e.NewPageIndex;
                GetGroups();
            }
            catch (Exception ex)
            {
                Throw ex;
            }
        }


//This RowDeleting Event is used for deleting a single record at a time. 

        protected void grdGroups_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
            try
            {
                objGrp.GroupID = Convert.ToInt32(Session["GroupID"].ToString());
                objGrp.UserID = Convert.ToInt32(Session["loginid"].ToString());
                objGrp.DeleteGroup();// This method contains original logic for deleting the record.
                GetGroups();
            }
            catch (Exception ex)
            {
               Throw ex;
            }
        }
//RowEditing Event is used for setting up the selected record in edit mode.

        protected void grdGroups_RowEditing(object sender, GridViewEditEventArgs e)
        {
            try
            {
                grdGroups.EditIndex = e.NewEditIndex;
                GetGroups();
            }
            catch (Exception ex)
            {
               Throw ex;
            }
        }

//CancelEdit Event is used for reset the selected record from edit mode.
        protected void grdGroups_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
        {
            try
            {
                grdGroups.EditIndex = -1;
                GetGroups();
            }
            catch (Exception ex)
            {
               Throw ex;
            }
        }

//After Edit the selected record values, this RowUpdating Event is used to update the edited values.

        protected void grdGroups_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
            try
            {
                TextBox txt = (TextBox)grdGroups.Rows[e.RowIndex].FindControl("txtgroupName");
                grdGroups.EditIndex = -1;
                objGrp.GroupName = txt.Text.Trim();
                objGrp.GroupID = Convert.ToInt32(Session["GroupID"].ToString());
                objGrp.UserID = Convert.ToInt32(Session["loginid"].ToString());
                objGrp.UpdateGroup(); // This method contains original logic to update the record on database.
                GetGroups();
            }
            catch (Exception ex)
            {
                Throw ex;
            }
        }

//This event is used for external purposes like button click events inside a grid.
        protected void grdGroups_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            try
            {
                if (e.CommandName.ToString() == "Update")
                {
                    Session["GroupID"] = e.CommandArgument.ToString();
                }
                if (e.CommandName.ToString() == "Delete")
                {
                    Session["GroupID"] = e.CommandArgument.ToString();
                }
            }
            catch (Exception ex)
            {
               throw ex;
            }
        }

//Row_Sorting Event is used for sorting the record by selecting the column.

        protected void grdGroups_Sorting(object sender, GridViewSortEventArgs e)
        {
            try
            {
                DataTable dt = ((DataSet)ViewState["GroupList"]).Tables[0];
                dt.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortExpression);
                grdGroups.DataSource = dt;
                grdGroups.DataBind();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }


 private void GetGroups()
        {
            try
            {
                objGrp.UserID = Convert.ToInt32(Session["loginid"].ToString());
                DataSet ds = objGrp.GetGroupsbyUser();
                ViewState["GroupList"] = ds;
                if (ds.Tables[0].Rows.Count > 0)
                {
                    grdGroups.DataSource = ds.Tables[0];
                    grdGroups.DataBind();
                }
                else
                {
                   // Below code is used for displaying some text if there is no record to bind to grid.
                    ds.Tables[0].Rows.Add(ds.Tables[0].NewRow());
                    grdGroups.DataSource = ds;
                    grdGroups.DataBind();
                    int columnscount = grdGroups.Columns.Count;
                    grdGroups.Rows[0].Cells.Clear();
                    grdGroups.Rows[0].Cells.Add(new TableCell());
                    grdGroups.Rows[0].Cells[0].ColumnSpan = columnscount;
                    grdGroups.Rows[0].Cells[0].HorizontalAlign = HorizontalAlign.Center;
                    grdGroups.Rows[0].Cells[0].ForeColor = System.Drawing.Color.Red;
                    grdGroups.Rows[0].Cells[0].Font.Bold = true;
                    grdGroups.Rows[0].Cells[0].Text = "No Groups List";
                }
            }
            catch (Exception ex)
            {
                Throw ex;
            }
        }


//This method is used in Row_Sorting Event.
private string GetSortDirection(string column)
        {

            // By default, set the sort direction to ascending.
            string sortDirection = "ASC";

            // Retrieve the last column that was sorted.
            string sortExpression = ViewState["SortExpression"] as string;

            if (sortExpression != null)
            {
                // Check if the same column is being sorted.
                // Otherwise, the default value can be returned.
                if (sortExpression == column)
                {
                    string lastDirection = ViewState["SortDirection"] as string;
                    if ((lastDirection != null) && (lastDirection == "ASC"))
                    {
                        sortDirection = "DESC";
                    }
                }
            }

            // Save new values in ViewState.
            ViewState["SortDirection"] = sortDirection;
            ViewState["SortExpression"] = column;

            return sortDirection;
        }       


Code Behind

 <asp:GridView ID="grdGroups" runat="server" AutoGenerateColumns="false"
                CssClass="GridStyle" AllowPaging="True"
        onpageindexchanging="grdGroups_PageIndexChanging"
        onrowcancelingedit="grdGroups_RowCancelingEdit"
        onrowdeleting="grdGroups_RowDeleting" onrowediting="grdGroups_RowEditing"
        onrowupdating="grdGroups_RowUpdating" PageSize="5" Width="70%"
            onrowcommand="grdGroups_RowCommand" onsorting="grdGroups_Sorting" AllowSorting="true">
        <Columns>
        <asp:TemplateField>
        <ItemTemplate>
            <asp:CheckBox ID="CheckBoxSelect" runat="server" Enabled="false"/>
        </ItemTemplate>
        <EditItemTemplate>
        <asp:CheckBox ID="CheckBoxSelect" runat="server" Enabled="false"/>
        </EditItemTemplate>
        </asp:TemplateField>    
         <asp:TemplateField HeaderText="GroupName" HeaderStyle-Width="250px" SortExpression="groupname">
        <ItemTemplate>      
        <%#Eval("groupname")%>
        </ItemTemplate>
        <EditItemTemplate>
            <asp:TextBox ID="txtgroupName" runat="server" CssClass="controlStyle" Text='<%#Eval("groupname")%>' MaxLength="20">
            </asp:TextBox>
            <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"
            ErrorMessage="! Enter group Name" ControlToValidate="txtgroupName" ValidationGroup="G" Text="!!">
            </asp:RequiredFieldValidator>
        </EditItemTemplate>

        </asp:TemplateField>  
        <asp:TemplateField HeaderText="Edit" HeaderStyle-Width="150px" SortExpression="GroupID">
        <ItemTemplate>
            <asp:LinkButton ID="lnkGroupEdit" runat="server" CommandName="Edit" ToolTip="Edit this Group"
            Text="Edit"></asp:LinkButton>      
        </ItemTemplate>
        <EditItemTemplate>
        <asp:LinkButton ID="lnkGroupUpdate" runat="server" CommandArgument='<%#Eval("GroupID")%>' CommandName="Update"
            Text="Update" ValidationGroup="G" ToolTip="Update"></asp:LinkButton>
            <asp:LinkButton ID="lnkCancel" runat="server" CommandName="Cancel"
            Text="Cancel"></asp:LinkButton>
            <asp:ValidationSummary ID="ValidationSummary1" runat="server" ShowMessageBox="true" ShowSummary="false" ValidationGroup="G"/>
        </EditItemTemplate>

        </asp:TemplateField>  
         <asp:TemplateField HeaderText="Delete">
        <ItemTemplate>
            <asp:LinkButton ID="lnkGroupDelete" runat="server" CommandArgument='<%#Eval("GroupID")%>' CommandName="Delete" Text="Delete"
             ToolTip="Delete this Group" OnClientClick="javascript:return confirm('If you delete this Group, all Contacts of this Group Also Deleted,Are you sure you want to delete this Item?');"></asp:LinkButton>      
        </ItemTemplate>
        <EditItemTemplate>      
        </EditItemTemplate>
        </asp:TemplateField>
        </Columns>
        <HeaderStyle CssClass="GridHeader" />
        <AlternatingRowStyle CssClass="GridAlter" />
        <RowStyle CssClass="gridrowstyle" />
        <PagerStyle CssClass="GridPager" />      
        </asp:GridView>  
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Tuesday, October 18, 2011

SMTP server configuration in windows server 2003

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