如何从支持 AJAX 的用户控件向客户端用户控件和父 ASPX 页面传递值

引言

这个项目的核心是构建一个启用了 Ajax 的对话框类型的基础用户控件。当点击按钮时，它会弹出一个 GridView 弹出用户控件，用户可以在其中选择一些值，并将选定的值发送回客户端页面，然后发送到父 ASPX 页面。数据可以以 DataSet 的形式发送到客户端页面，并从客户端页面发送到父页面。

背景

请阅读如何在使用用户控件之间传递值

• https://codeproject.org.cn/KB/grid/User_control.aspx

Using the Code

1. 设置 - 创建一个如下所示的基础用户控件。

   

2. 创建客户端用户控件页面，将基础控件拖放到客户端用户控件页面上。客户端页面可以继承基础用户控件：客户端用户控件：基础用户控件

   //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. 在从控件中选择值后，用户可以按下“添加”按钮以将选定的值作为数据集返回。

   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. 将客户端页面拖放到父页面上。
5. 这是一个在 POPup Grid 中显示数据的示例

历史

• 2008年3月13日：初始发布