How to Pass Value from Ajax Enabled Base User Control to Client User Control and to the Parent ASPX Page

Introduction

What this project is all about is building an Ajax enabled dialog type Base User Control. When the button is clicked, it pops up a GridView Popup User Control, from where the user selects some values and the selected values are sent back to the Client page and then to the Parent ASPX page. Data can be sent in the form of DataSet to the client page and from client page to the Parent page.

Background

Please read how to pass a value between user controls:

• http://www.codeproject.com/KB/grid/User_control.aspx

Using the Code

1. Setup - create a Base user Control like this.

   

2. Create a Client User control page drag and drop base control on to the client user control page. Client page can inherit the Base user control Client user control: Base user control
   C#

   //Base Control Codes    
   //Define the Delegate and Event
       public delegate void Ep_UserControlCommandEventHandler
   	(object sender, AB_UserControlCommandEventArgs e);
       public event AB_UserControlCommandEventHandler AjaxGridSelectedData;
   //User can set the DataSet from the Client User Control user can 
   //pass a data for the GridView of the Base control from Client User control;
   //Define the DataSet property on base control
       private DataSet data;
       public DataSet Parent_DataSet
       {
           set
           {
               data = value; ;
           }
       }
   
   //When user clicks on the show dialog button. This is base control event
   protected void Show_Click(object sender, EventArgs e)
       {
           GridView1.DataSource = data; 
           GridView1.DataBind();
           BPanel.Update();
           mdlPopup.Show();
       }
   
   //Define the virtual method this method needs to implement 
   //in the client page to access the return data set value
     protected virtual void OnAB_AjaxGridSelectedData(AB_UserControlCommandEventArgs e)
       {
           if (AjaxGridSelectedData != null) AjaxGridSelectedData(this, e);
       }
   
   //Pass the Selected values to the Client Page by Base Command event
   AB_UserControlCommandEventArgs(N_data));

3. After selecting the values from the control, the user can press the add button to return the selected values as dataset.
   C#

   protected void btnadd_Click(object sender, EventArgs e)
   {
   DataTable dt = new DataTable();
   dt.Columns.Add(new DataColumn("Id", typeof(string)));
   dt.Columns.Add(new DataColumn("Name", typeof(string)));
   dt.Columns.Add(new DataColumn("Is_Selected", typeof(Boolean)));
   ArrayList Id_List = (ArrayList)Session["CHECKED_ITEMS"];
   foreach (GridViewRow Ro in GridView1.Rows)
   {
   bool isChecked = ((CheckBox)Ro.FindControl("Is_Selected")).Checked;
   if (isChecked)
   {
   if (Id_List != null)
   {
   Id_List.Add(Ro.Cells[0].Text);
   }
   else
   {
   DataRow dra = dt.NewRow();
   dra["Id"] = Ro.Cells[0].Text;
   dra["Name"] = Ro.Cells[1].Text;
   dra["Is_Selected"] = true;
   dt.Rows.Add(dra);
   }
   }
   }
   if(Id_List!=null)
   {
   string Id_s ="'";
   for (int i = 0; i < Id_List.Count; i++)
   {
   Id_s += Id_List[i].ToString() +"','";
   }
   DataTable MyTable = data.Tables[0];
   DataRow[] test;
   string Slect = "Id in (" + Id_s + ")";
   Slect=Slect.Replace(",')", ")");
   test = MyTable.Select(Slect);
   foreach (DataRow rw in test)
   {
   DataRow dr = dt.NewRow();
   dr["Id"]=rw["Id"];
   dr["Name"]=rw["Name"];
   dr["Is_Selected"]=true;
   dt.Rows.Add(dr);
   }
   }
   DataSet N_data = new DataSet();
   N_data.Tables.Add(dt);
   OnEp_AjaxGridSelectedData(new AB_UserControlCommandEventArgs(N_data));
   mdlPopup.Hide();
   }
         
   //Client User control page implements the base control event
   protected void Page_Load(object sender, EventArgs e)
   {
   AjaxGridViewBaseControl1.Parent_DataSet = Main_GridData();
   AjaxGridViewBaseControl1.AjaxGridSelectedData += 
   	new AB_UserControlCommandEventHandler(OnAjaxGridSelectedData);
   }
   //Get value from Base
   private void OnAjaxGridSelectedData(object sender, AB_UserControlCommandEventArgs e)
   {
   //The selected values can be displayed in client control 
   //and even return back to parent page
   GridView1.DataSource = e.EpDataSet;
   GridView1.DataBind();
   }

4. Drag and drop the client page on the parent page.
5. This is an example of how the data is displayed in the POPup Grid

History

• 13^th March, 2008: Initial post