在gridview（Web应用程序）C#中添加数据答案

【问题标题】：adding data in gridview (web application) C#在gridview（Web应用程序）C#中添加数据
【发布时间】：2017-12-18 08:02:12
【问题描述】：

我的 Web 应用程序中有 gridview

这个网格视图应该显示 3 列（表、列、new_columns）

我想在单击事件中显示网格视图，在该事件中我想绑定第一个字段（表）中的所有表，并将每个表的所有相应列绑定到网格视图内的下拉列表中，并在第二个下拉列表中绑定所有新列列表

这里是代码

        DataTable test = new DataTable();
        DataTable _dbtest = new DataTable();
        list_of_table_of_old_database = db.Select("", "", "", "", "", "", "", "", "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.tables WHERE TABLE_SCHEMA = '" + old_database.Text.Trim() + "' ", "");
        list_of_table_of_current_database = db.Select("", "", "", "", "", "", "", "", "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.tables WHERE TABLE_SCHEMA = '" + new_database.Text.Trim() + "' ", "");

        DataView view = new DataView(list_of_table_of_old_database);


        DataTable dtTable = new DataTable();


        test = db.Select("", "", "", "", "", "", "", "", "select  distinct k.table1 from (SELECT TABLE_NAME as table1 FROM INFORMATION_SCHEMA.tables WHERE TABLE_SCHEMA = '" + old_database.Text.Trim() + "') as k INNER JOIN (SELECT TABLE_NAME as table2 FROM INFORMATION_SCHEMA.tables WHERE TABLE_SCHEMA = '" + new_database.Text.Trim() + "')as a;", "");




        DropDownList3.Items.Clear();
        DropDownList3.Items.Insert(0, "--select--");

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

                _dbtest = db.Select("", "", "", "", "", "", "", "", "select a.fieldname from (SELECT COLUMN_NAME as fieldname FROM INFORMATION_SCHEMA.columns WHERE TABLE_SCHEMA = '" + old_database.Text.Trim() + "' and TABLE_NAME =  '" + test.Rows[i][0].ToString() + "') as A LEFT JOIN (SELECT COLUMN_NAME as fieldname FROM INFORMATION_SCHEMA.columns WHERE TABLE_SCHEMA = '" + new_database.Text.Trim() + "' and TABLE_NAME =  '" + test.Rows[i][0].ToString() + "') B on (A.fieldname = B.fieldname) where B.fieldname is null ", "");

                if (_dbtest.Rows.Count > 0)
                {

                    //here i want to display all tables in the gridview row by row (test.Rows[i][0].ToString())


                } 

                  // and i want to bind all columns (_dbtest) of each tables inside the loop in first dropdownlist in gridview 

                 // and same  columns (_dbtest) of each tables inside the loop in second dropdownlist in gridview
            }

我想在运行循环时找到一些方法在gridview中绑定数据，这样我就可以为每个字段提供正确的数据

这是HTML代码

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
        Height="237px" Width="632px" onrowdatabound="GridView1_RowDataBound">
        <Columns>
            <asp:TemplateField FooterText="tables" HeaderText="tables">
                <EditItemTemplate>
                    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
                </EditItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField FooterText="columns" HeaderText="columns">
                <ItemTemplate>
                    <asp:DropDownList ID="ddlcolumns" runat="server" 
                         Height="16px" Width="181px">
                    </asp:DropDownList>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField FooterText="vms-columns" HeaderText="vms-columns">
                <ItemTemplate>
                    <asp:DropDownList ID="ddl_vms_columns" runat="server" 
                         Height="20px" Width="153px">
                    </asp:DropDownList>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

所以最后，此网格视图将在网格视图中显示所有表格以及该表格的每一列

【问题讨论】：

标签： c# asp.net gridview

【解决方案1】：

第一步是加载所有表格并将其绑定到您的 gridView。您不会使用事件 GridView1_RowDataBound 来执行此操作。

加载表格后，您可以使用事件 GridView1_RowDataBound 来填充 DropDownLists。您可以找到一些示例来解释如何做到这一点：

https://www.aspsnippets.com/Articles/How-to-populate-DropDownList-in-GridView-in-ASPNet.aspx

https://codepedia.info/bind-dropdownlist-inside-gridview-edit-template/

【讨论】：