Устранение неполадок при чтении динамически генерируемого поля шаблона в gridview с управлением меткой и выпадающим меню на кнопке сохранения.

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I have taken a gridview with auto generatedcolumns is false. I am creating column of this gridview on run time by C# . I have createded columns of the gridview by datatable on OnRowCreated event of gridview . In each column of gridview there is some label control and a dropdown control . On Page Init I have bind the grid. Now grid is loaded with relevant data. But I am not able to read labels and dropdown control when want to save the selected dropdowns value by a button outside the grid.

Проблема, возникающая из-за переменного количества столбцов. Это зависит от запроса базы данных. При попытке найти элемент управления на кнопке сохранения вне сетки он выдает ошибку.

Что я уже пробовал:

охраняемых недействительными в(объект отправителя, EventArgs в электронной)
{

Набор Product_Sub = sub_get.Sp_Class_Subject_Get(school_id);
DataTable UniqueSubject = RemoveDuplicateRows(Product_Sub.Tables[0], "SUBJECT_NAME");
DataTable UniqueClass = Product_Sub.Tables[1];
CreateGridView(UniqueSubject);
Управления gridview1.Источник Данных = CreateDatatable(UniqueSubject, UniqueClass);
Управления gridview1.Привязку();
}

protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
        {
            if (flagGenerateGrid)
            {
                if (e.Row.RowType == DataControlRowType.DataRow)
                {
                    DataTable dt = new DataTable();
                    dt = (DataTable)ViewState["dt"];
                    DataTable dtProduct = new DataTable();

                    int counter = Convert.ToInt32(dt.Columns.Count);

                    Label LblClass = new Label();
                    LblClass.ID = "LblClassName";
                    LblClass.Text = (e.Row.DataItem as DataRowView).Row[0].ToString();
                    e.Row.Cells[0].Controls.Add(LblClass);

                    for (int column = 1; column < counter; column++)
                    {
                        Label LblClubId = new Label();
                        LblClubId.ID = "Lbl_Club_ID_" + column;
                        LblClubId.Text = (e.Row.DataItem as DataRowView).Row[column].ToString();
                        LblClubId.Visible = false;
                        e.Row.Cells[column].Controls.Add(LblClubId);

                        string clubId = (e.Row.DataItem as DataRowView).Row[column].ToString();
                        string[] arrayId = clubId.Split(',');
                        int classId = Convert.ToInt32(arrayId[0]);
                        int productId = Convert.ToInt32(arrayId[1]);
                        int subjectId = Convert.ToInt32(arrayId[2]);
                        int subjectMasterId = Convert.ToInt32(arrayId[3]);

                        Label LblClassId = new Label();
                        LblClassId.ID = "Lbl_CLASS_ID";
                        LblClassId.Text = Convert.ToString(classId);
                        e.Row.Cells[column].Controls.Add(LblClassId);

                        Label LblSubjectMasterId = new Label();
                        LblSubjectMasterId.ID = "Lbl_SUBJECT_MASTER_ID";
                        LblSubjectMasterId.Text = Convert.ToString(subjectMasterId);
                        e.Row.Cells[column].Controls.Add(LblSubjectMasterId);

                        Label LblAppId = new Label();
                        LblAppId.ID = "Lbl_APP_ID";
                        LblAppId.Text = Convert.ToString(productId);
                        e.Row.Cells[column].Controls.Add(LblAppId);

                        Label LblProductId = new Label();
                        LblProductId.ID = "Lbl_PRODUCT_ID";
                        LblProductId.Text = Convert.ToString(productId);
                        e.Row.Cells[column].Controls.Add(LblProductId);

                        Label LblSubjectId = new Label();
                        LblSubjectId.ID = "Lbl_SUBJECT_ID";
                        LblSubjectId.Text = Convert.ToString(subjectId);
                        e.Row.Cells[column].Controls.Add(LblSubjectId);

                        DropDownList DdlProduct = new DropDownList();
                        DdlProduct.ID = "DdlProductId";
                        DdlProduct.AppendDataBoundItems = true;
                        DdlProduct.AutoPostBack = true;
                        DdlProduct.DataTextField = "PRODUCT_NAME";
                        DdlProduct.DataValueField = "PRODUCT_ID";
                        DdlProduct.DataSource = null;
                        DdlProduct.DataBind();
                        dtProduct = sub_get.Sp_Product_Subject_Class_Get(school_id, classId, subjectMasterId);
                        DdlProduct.DataSource = dtProduct;
                        DdlProduct.DataBind();
                        if (dtProduct.Rows.Count == 0)
                        {
                            LblClubId.Visible = false;
                            LblClassId.Visible = false;
                            LblSubjectMasterId.Visible = false;
                            LblAppId.Visible = false;
                            LblProductId.Visible = false;
                            LblSubjectId.Visible = false;
                            DdlProduct.Visible = false;
                        }
                        else
                        {
                            LblClubId.Visible = false;
                            LblClassId.Visible = true;
                            LblSubjectMasterId.Visible = true;
                            LblAppId.Visible = true;
                            LblProductId.Visible = true;
                            LblSubjectId.Visible = true;
                            DdlProduct.Visible = true;
                        }
                        DdlProduct.SelectedIndexChanged += DdlProductId_SelectedIndexChanged;
                        e.Row.Cells[column].Controls.Add(DdlProduct);
                    }
                }
            }
        }

protected void CreateGridView(DataTable dtSubject)
       {
           TemplateField field = new TemplateField();
           PlaceHolder ph = new PlaceHolder();
           field.HeaderText = "Class";
           GridView1.Columns.Add(field);

           foreach (DataRow dr in dtSubject.Rows)
           {
               TemplateField tfield = new TemplateField();
               tfield.HeaderText = Convert.ToString(dr["SUBJECT_NAME"]);
               GridView1.Columns.Add(tfield);
           }
       }
       protected DataTable CreateDatatable(DataTable dtSubject, DataTable dtClass)
       {
           try
           {
               DataTable dt = new DataTable();
               dt.Columns.Add("Class", typeof(System.String));
               foreach (DataRow dr in dtSubject.Rows)
               {
                   dt.Columns.Add(Convert.ToString(dr["SUBJECT_NAME"]), typeof(System.String));
               }
               DataRow DataRowNew;
               for (int row = 0; row < dtClass.Rows.Count; row++)
               {
                   DataRowNew = dt.NewRow();

                   DataRowNew["Class"] = Convert.ToString(dtClass.Rows[row]["CLASS_NAME"]);

                   for (int column = 0; column < dtSubject.Rows.Count; column++)
                   {
                       DataRowNew[Convert.ToString(dtSubject.Rows[column]["SUBJECT_NAME"])] = Convert.ToString(dtClass.Rows[row][0]) + "," + Convert.ToString(dtSubject.Rows[column]["PRODUCT_ID"]) + "," + Convert.ToString(dtSubject.Rows[column]["SUBJECT_ID"]) + "," + Convert.ToString(dtSubject.Rows[column]["SUBJECT_MASTER_ID"]);
                   }
                   //foreach (DataRow dr in dtSubject.Rows)
                   //{
                   //    DataRowNew[Convert.ToString(dr["SUBJECT_NAME"])] = Convert.ToString(dtClass.Rows[row][0]) + " " + Convert.ToString(dtSubject.Rows[row]["SUBJECT_ID"]);
                   //}
                   dt.Rows.Add(DataRowNew);
               }
               ViewState["dt"] = dt;
               return dt;
           }
           catch (Exception ex)
           {
               Elmah.ErrorSignal.FromCurrentContext().Raise(ex);
               throw ex;
           }
       }

protected void btn_Save_Click(object sender, EventArgs e)
  {
      DataTable dtGridViewBind = new DataTable();
      DataColumn dtColumn;
      DataRow myDataRow;


      // Create SCHOOL_ID Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "SCHOOL_ID";
      dtColumn.Caption = "SCHOOL_ID";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

      // Create APP_ID Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "PRODUCT_ID";
      dtColumn.Caption = "PRODUCT_ID";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

      // Create SUBJECT_ID Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "SUBJECT_ID";
      dtColumn.Caption = "SUBJECT_ID";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

      // Create SUBJECT_MASTER_ID Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "SUBJECT_MASTER_ID";
      dtColumn.Caption = "SUBJECT_MASTER_ID";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

      // Create CREATED_BY Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "CREATED_BY";
      dtColumn.Caption = "CREATED_BY";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

      // Create APP_ID Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "NEW_PRODUCT_ID";
      dtColumn.Caption = "NEW_PRODUCT_ID";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

      // Create SUBJECT_ID Column
      dtColumn = new DataColumn();
      dtColumn.DataType = System.Type.GetType("System.Int32");
      dtColumn.ColumnName = "NEW_SUBJECT_ID";
      dtColumn.Caption = "NEW_SUBJECT_ID";
      dtColumn.ReadOnly = false;
      dtGridViewBind.Columns.Add(dtColumn);

try
           {
               //for (int i = 0; i < GridView1.Columns.Count; i++)
               //{
               //    DropDownList dl = (DropDownList)GridView1.Rows[i].FindControl("DdlProductId");

               //    for (int j = 0; j < GridView1.Rows.Count; j++)
               //    {
               //        Label l1 = (Label)GridView1.Rows[i].Cells[2].FindControl("lbl" + j);
               //        TextBox t = (TextBox)GridView1.Rows[i].Cells[3].FindControl("txt" + j);

               //    }
               //}

               for (int rows = 1; rows < GridView1.Rows.Count; rows++)
               {
                   for (int column = 1; column < GridView1.Rows.Count; column++)
                   {
                       Label Lbl_SUBJECT_MASTER_ID = (Label)GridView1.Rows[column].FindControl("Lbl_SUBJECT_MASTER_ID_" + (rows-1));
                       int subjectMasterId = Convert.ToInt32(Lbl_SUBJECT_MASTER_ID.Text);

                       //Label l1 = (Label)GridView1.Rows[column].FindControl("Lbl_SUBJECT_MASTER_ID");
                       //int sId = Convert.ToInt32(l1.Text);

                       //DropDownList DdlProductId = (DropDownList)GridView1.Rows[column].FindControl("DdlProductId");
                       //int productId = Convert.ToInt32(DdlProductId.SelectedValue);

                       //Label Lbl_SUBJECT_MASTER_ID = (Label)GridView1.Rows[rows].FindControl("Lbl_SUBJECT_MASTER_ID_"+ rows);

                       //Label Lbl_SUBJECT_MASTER_ID = (Label)row.FindControl("Lbl_SUBJECT_MASTER_ID");
                       //Label Lbl_PRODUCT_ID = (Label)row.FindControl("Lbl_PRODUCT_ID");
                       //Label Lbl_APP_ID = (Label)row.FindControl("Lbl_APP_ID");
                       //DropDownList DropDownList1 = (DropDownList)row.FindControl("DdlProductId");
                       //Label Lbl_SUBJECT_ID = (Label)row.FindControl("Lbl_SUBJECT_ID");

                       //int subjectMasterId = Convert.ToInt32(Lbl_SUBJECT_MASTER_ID.Text);
                       //int productId = Convert.ToInt32(Lbl_PRODUCT_ID.Text);
                       //int appId = Convert.ToInt32(Lbl_APP_ID.Text);
                       //int subjectId = Convert.ToInt32(Lbl_SUBJECT_ID.Text);

                   }
               }
               //foreach (GridViewRow row in GridView1.Rows)
               //{

               //    Label Lbl_SUBJECT_MASTER_ID = (Label)row.FindControl("Lbl_SUBJECT_MASTER_ID");
               //    Label Lbl_CREATED_BY = (Label)row.FindControl("Lbl_CREATED_BY");
               //    Label Lbl_PRODUCT_ID = (Label)row.FindControl("Lbl_PRODUCT_ID");
               //    Label Lbl_APP_ID = (Label)row.FindControl("Lbl_APP_ID");
               //    DropDownList DropDownList1 = (DropDownList)row.FindControl("DdlProductId");

               //    Label Lbl_NEW_SUBJECT_ID = (Label)row.FindControl("Lbl_NEW_SUBJECT_ID");
               //    Label Lbl_SUBJECT_ID = (Label)row.FindControl("Lbl_SUBJECT_ID");


               //    DataSet Product_Get = sub_get.Sp_Product_Get(school_id);
               //    DataView dt2 = Product_Get.Tables[0].DefaultView;
               //    dt2.RowFilter = "PRODUCT_ID = '" + DropDownList1.SelectedValue + "'";

               //    DataRow[] rowSubject = Product_Get.Tables[0].Select("PRODUCT_ID=" + DropDownList1.SelectedValue + " and SUBJECT_MASTER_ID =" + Lbl_SUBJECT_MASTER_ID.Text);

               //    if (Convert.ToString(Lbl_PRODUCT_ID.Text) != Convert.ToString(Lbl_APP_ID.Text))
               //    {
               //        myDataRow = dtGridViewBind.NewRow();
               //        myDataRow["SCHOOL_ID"] = school_id;
               //        myDataRow["SUBJECT_ID"] = Lbl_SUBJECT_ID.Text;
               //        myDataRow["PRODUCT_ID"] = Convert.ToString(Lbl_APP_ID.Text);
               //        myDataRow["SUBJECT_MASTER_ID"] = Lbl_SUBJECT_MASTER_ID.Text;
               //        myDataRow["CREATED_BY"] = Login_ID;
               //        myDataRow["NEW_PRODUCT_ID"] = Lbl_PRODUCT_ID.Text;
               //        myDataRow["NEW_SUBJECT_ID"] = Lbl_NEW_SUBJECT_ID.Text;
               //        dtGridViewBind.Rows.Add(myDataRow);
               //    }
               //}

               //sub_get.Sp_Product_Saved(dtGridViewBind);

               //DataTable Product_Sub1 = sub_get.Sp_Product_Subject_Get(school_id);
               //DataTable UniqueRecords = RemoveDuplicateRows(Product_Sub1, "SUBJECT_NAME");

               //GridView1.DataSource = UniqueRecords;
               //GridView1.DataBind();

               //Page.ClientScript.RegisterStartupScript(this.GetType(), Guid.NewGuid().ToString(), "myFunction('Saved')", true);

           }
           catch (Exception ex)
           {
               Elmah.ErrorSignal.FromCurrentContext().Raise(ex);
               throw ex;
           }

       }

Когда я пытаюсь найти значение метки или выбранное значение в выпадающем списке . Я получаю ошибку, что "object refrence не установлен в экземпляр объекта". Пожалуйста, помогите мне. Заранее спасибо.

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