c# - 通过单击 asp.net 中的按钮在网格中添加多行

Question

我需要通过单击按钮在 Gridview 中动态添加“n”行和“m”列(行包含 m 个文本框) 对于前。当用户点击按钮时，一个特定的整数值被初始化为一个变量，该变量是所需的行数。假设它的值为 8，那么已经动态创建了包含 m 个文本框的 8 行。`

目前我浏览了这个文档并实现了相同的内容: link

对于多行功能，我只是添加了一些约束并注释了一些不需要的代码，如下所示:

 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)));
        dt.Columns.Add(new DataColumn("Column2", typeof(string)));
        dt.Columns.Add(new DataColumn("Column3", typeof(string)));
        dr = dt.NewRow();
        dr["RowNumber"] = 1;
        dr["Column1"] = string.Empty;
        dr["Column2"] = string.Empty;
        dr["Column3"] = string.Empty;
        dt.Rows.Add(dr);

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

        Gridview1.DataSource = dt;
        Gridview1.DataBind();
    }
    private void AddNewRowToGrid()
    {
        try
        {
            int j = 8, rowIndex = 0;

            //if (ViewState["CurrentTable"] != null)
            //{
            DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
            DataRow drCurrentRow = null;
            if (dtCurrentTable.Rows.Count > 0)
            {
                for (int i = 1; i <= j; i++)
                {
                    //extract the TextBox values
                    TextBox box1 = (TextBox)Gridview1.Rows[rowIndex].Cells[1].FindControl("TextBox1");
                    TextBox box2 = (TextBox)Gridview1.Rows[rowIndex].Cells[2].FindControl("TextBox2");
                    TextBox box3 = (TextBox)Gridview1.Rows[rowIndex].Cells[3].FindControl("TextBox3");

                    drCurrentRow = dtCurrentTable.NewRow();
                    drCurrentRow["RowNumber"] = i + 1;

                    dtCurrentTable.Rows[i - 1]["Column1"] = box1.Text;
                    dtCurrentTable.Rows[i - 1]["Column2"] = box2.Text;
                    dtCurrentTable.Rows[i - 1]["Column3"] = box3.Text;

                    ++rowIndex;
                }
                dtCurrentTable.Rows.Add(drCurrentRow);
                ViewState["CurrentTable"] = dtCurrentTable;

                Gridview1.DataSource = dtCurrentTable;
                Gridview1.DataBind();
            }
        }
        catch (Exception ex)
        {

        }
        //}
        //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[rowIndex].Cells[1].FindControl("TextBox1");
    //                TextBox box2 = (TextBox)Gridview1.Rows[rowIndex].Cells[2].FindControl("TextBox2");
    //                TextBox box3 = (TextBox)Gridview1.Rows[rowIndex].Cells[3].FindControl("TextBox3");

    //                box1.Text = dt.Rows[i]["Column1"].ToString();
    //                box2.Text = dt.Rows[i]["Column2"].ToString();
    //                box3.Text = dt.Rows[i]["Column3"].ToString();

    //                rowIndex++;
    //            }
    //        }
    //    }
    //}
    protected void Page_Load(object sender, EventArgs e)
    {

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

调试后出现错误:索引超出范围。必须为非负数且小于集合的大小。

Answer 1

试试这个

 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)));
           dt.Columns.Add(new DataColumn("Column2", typeof(string)));
           dt.Columns.Add(new DataColumn("Column3", typeof(string)));
           dr = dt.NewRow();
           dr["RowNumber"] = 1;
           dr["Column1"] = string.Empty;
           dr["Column2"] = string.Empty;
           dr["Column3"] = string.Empty;
           dt.Rows.Add(dr);
           ViewState["CurrentTable"] = dt;

           Gridview1.DataSource = dt;
           Gridview1.DataBind();
       }
       private void AddNewRowToGrid()
       {
           try
           {
               int j = 8, rowIndex = 0;

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

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

                       //extract the TextBox values
                     TextBox  box1 = (TextBox)Gridview1.Rows[rowIndex].Cells[1].FindControl("TextBox1");
                     TextBox  box2 = (TextBox)Gridview1.Rows[rowIndex].Cells[2].FindControl("TextBox2");
                     TextBox  box3 = (TextBox)Gridview1.Rows[rowIndex].Cells[3].FindControl("TextBox3");

                       drCurrentRow = dtCurrentTable.NewRow();
                       drCurrentRow["RowNumber"] = i + 1;

                       dtCurrentTable.Rows[i - 1]["Column1"] = box1.Text;
                       dtCurrentTable.Rows[i - 1]["Column2"] = box2.Text;
                       dtCurrentTable.Rows[i - 1]["Column3"] = box3.Text;
                       dtCurrentTable.Rows.Add(drCurrentRow);
                   }
                  // dtCurrentTable.Rows.Add(drCurrentRow);
                   ViewState["CurrentTable"] = dtCurrentTable;

                   Gridview1.DataSource = dtCurrentTable;
                   Gridview1.DataBind();
               }
           }
           catch (Exception ex)
          {

           }

       protected void Page_Load(object sender, EventArgs e)
       {

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