Handle-Ereignis in dynamisch erstellte Schaltfläche in Gridview

Question

Ich habe dynamische textboxs und dropdownlist in gridview erstellt. Es funktioniert perfekt. Weiter möchte ich Event in Dynamic dropdownlist feuern und etwas unternehmen.

private ArrayList GetDummyData() { 

    ArrayList arr = new ArrayList(); 

    arr.Add(new ListItem("Item1", "1")); 
    arr.Add(new ListItem("Item2", "2")); 
    arr.Add(new ListItem("Item3", "3")); 
    arr.Add(new ListItem("Item4", "4")); 
    arr.Add(new ListItem("Item5", "5")); 

    return arr; 
} 

private void FillDropDownList(DropDownList ddl) { 
    ArrayList arr = GetDummyData(); 

    foreach (ListItem item in arr) { 
     ddl.Items.Add(item); 
    } 
} 

private void SetInitialRow() { 

    DataTable dt = new DataTable(); 
    DataRow dr = null; 

    dt.Columns.Add(new DataColumn("RowNumber", typeof(string))); 
    dt.Columns.Add(new DataColumn("Column1", typeof(string)));//for TextBox value 
    dt.Columns.Add(new DataColumn("Column2", typeof(string)));//for TextBox value 
    dt.Columns.Add(new DataColumn("Column3", typeof(string)));//for DropDownList selected item 
    dt.Columns.Add(new DataColumn("Column4", typeof(string)));//for DropDownList selected item 

    dr = dt.NewRow(); 
    dr["RowNumber"] = 1; 
    dr["Column1"] = string.Empty; 
    dr["Column2"] = string.Empty; 
    dt.Rows.Add(dr); 

    //Store the DataTable in ViewState for future reference 
    ViewState["CurrentTable"] = dt; 

    //Bind the Gridview 
    Gridview1.DataSource = dt; 
    Gridview1.DataBind(); 

    //After binding the gridview, we can then extract and fill the DropDownList with Data 
    DropDownList ddl1 = (DropDownList)Gridview1.Rows[0].Cells[3].FindControl("DropDownList1"); 
    DropDownList ddl2 = (DropDownList)Gridview1.Rows[0].Cells[4].FindControl("DropDownList2"); 
    FillDropDownList(ddl1); 
    FillDropDownList(ddl2); 
} 

private void AddNewRowToGrid() { 

    if (ViewState["CurrentTable"] != null) { 

     DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"]; 
     DataRow drCurrentRow = null; 

     if (dtCurrentTable.Rows.Count > 0) { 
      drCurrentRow = dtCurrentTable.NewRow(); 
      drCurrentRow["RowNumber"] = dtCurrentTable.Rows.Count + 1; 

      //add new row to DataTable 
      dtCurrentTable.Rows.Add(drCurrentRow); 
      //Store the current data to ViewState for future reference 

      ViewState["CurrentTable"] = dtCurrentTable; 


      for (int i = 0; i < dtCurrentTable.Rows.Count - 1; i++) { 

       //extract the TextBox values 

       TextBox box1 = (TextBox)Gridview1.Rows[i].Cells[1].FindControl("TextBox1"); 
       TextBox box2 = (TextBox)Gridview1.Rows[i].Cells[2].FindControl("TextBox2"); 

       dtCurrentTable.Rows[i]["Column1"] = box1.Text; 
       dtCurrentTable.Rows[i]["Column2"] = box2.Text; 

       //extract the DropDownList Selected Items 

       DropDownList ddl1 = (DropDownList)Gridview1.Rows[i].Cells[3].FindControl("DropDownList1"); 
       DropDownList ddl2 = (DropDownList)Gridview1.Rows[i].Cells[4].FindControl("DropDownList2"); 

       // Update the DataRow with the DDL Selected Items 

       dtCurrentTable.Rows[i]["Column3"] = ddl1.SelectedItem.Text; 
       dtCurrentTable.Rows[i]["Column4"] = ddl2.SelectedItem.Text; 

      } 

      //Rebind the Grid with the current data to reflect changes 
      Gridview1.DataSource = dtCurrentTable; 
      Gridview1.DataBind(); 
     } 
    } 
    else { 
     Response.Write("ViewState is null"); 

    } 
    //Set Previous Data on Postbacks 
    SetPreviousData(); 
} 

private void SetPreviousData() { 

    int rowIndex = 0; 
    if (ViewState["CurrentTable"] != null) { 

     DataTable dt = (DataTable)ViewState["CurrentTable"]; 
     if (dt.Rows.Count > 0) { 

      for (int i = 0; i < dt.Rows.Count; i++) { 

       TextBox box1 = (TextBox)Gridview1.Rows[i].Cells[1].FindControl("TextBox1"); 
       TextBox box2 = (TextBox)Gridview1.Rows[i].Cells[2].FindControl("TextBox2"); 

       DropDownList ddl1 = (DropDownList)Gridview1.Rows[rowIndex].Cells[3].FindControl("DropDownList1"); 
       DropDownList ddl2 = (DropDownList)Gridview1.Rows[rowIndex].Cells[4].FindControl("DropDownList2"); 

       //Fill the DropDownList with Data 
       FillDropDownList(ddl1); 
       FillDropDownList(ddl2); 

       if (i < dt.Rows.Count - 1) { 

        //Assign the value from DataTable to the TextBox 
        box1.Text = dt.Rows[i]["Column1"].ToString(); 
        box2.Text = dt.Rows[i]["Column2"].ToString(); 

        //Set the Previous Selected Items on Each DropDownList on Postbacks 
        ddl1.ClearSelection(); 
        ddl1.Items.FindByText(dt.Rows[i]["Column3"].ToString()).Selected = true; 

        ddl2.ClearSelection(); 
        ddl2.Items.FindByText(dt.Rows[i]["Column4"].ToString()).Selected = true; 

       } 

       rowIndex++; 
      } 
     } 
    } 
} 

protected void Page_Load(object sender, EventArgs e) { 
    if (!Page.IsPostBack) { 
     SetInitialRow(); 
    } 
} 

protected void ButtonAdd_Click(object sender, EventArgs e) { 
    AddNewRowToGrid(); 
} 

protected void Gridview1_RowCreated(object sender, GridViewRowEventArgs e) { 
    if (e.Row.RowType == DataControlRowType.DataRow) { 
     DataTable dt = (DataTable)ViewState["CurrentTable"]; 
     LinkButton lb = (LinkButton)e.Row.FindControl("LinkButton1"); 
     if (lb != null) { 
      if (dt.Rows.Count > 1) { 
       if (e.Row.RowIndex == dt.Rows.Count - 1) { 
        lb.Visible = false; 
       } 
      } 
      else { 
       lb.Visible = false; 
      } 
     } 
    } 
} 

protected void LinkButton1_Click(object sender, EventArgs e) { 
    LinkButton lb = (LinkButton)sender; 
    GridViewRow gvRow = (GridViewRow)lb.NamingContainer; 
    int rowID = gvRow.RowIndex; 
    if (ViewState["CurrentTable"] != null) { 

     DataTable dt = (DataTable)ViewState["CurrentTable"]; 
     if (dt.Rows.Count > 1) { 
      if (gvRow.RowIndex < dt.Rows.Count - 1) { 
       //Remove the Selected Row data and reset row number 
       dt.Rows.Remove(dt.Rows[rowID]); 
       ResetRowID(dt); 
      } 
     } 

     //Store the current data in ViewState for future reference 
     ViewState["CurrentTable"] = dt; 

     //Re bind the GridView for the updated data 
     Gridview1.DataSource = dt; 
     Gridview1.DataBind(); 
    } 

    //Set Previous Data on Postbacks 
    SetPreviousData(); 
} 

private void ResetRowID(DataTable dt) { 
    int rowNumber = 1; 
    if (dt.Rows.Count > 0) { 
     foreach (DataRow row in dt.Rows) { 
      row[0] = rowNumber; 
      rowNumber++; 
     } 
    } 
} 

Answer 1

kann ein Duplikat der Frage:

how to add an OnClick event on DropDownList's ListItem that is added dynamically?

Bitte überprüfen Sie die dort gegebene Antwort.

DropDownList changesList = new DropDownList(); 

ListItem item; 
item = new ListItem(); 
item.Text = "go to google.com"; 
item.Value = "http://www.google.com"; 

changesList.Items.Add(item); 
changesList.Attributes.Add("onChange", "location.href = this.options[this.selectedIndex].value;"); 

Auch haben Sie versucht, ein Handler auf das Ereignis Hinzufügen dynamisch SelectedIndexChanged, wenn an das Netz die neue Zeile hinzufügen?