无法找到在gridview行中动态创建的dropdonlist控件 [英] Cant able to find the dropdonlist control which dynamically created in gridview row

问题描述

我在gridview rowdatabound中创建了动态下拉列表，请参阅下面的代码。

 DropDownList ddlResult =  new  DropDownList（）; 
 ddlResult.ID =   ddlResult; 
 ddlResult.AutoPostBack =  true ; 
 ddlResult.SelectedIndexChanged + = ddlResult_SelectedIndexChanged; 
 ddlResult.Items.Insert（ 0 ， new  ListItem（  PASS，  0\" ））; 
 ddlResult.Items.Insert（ 1 ， new  ListItem（  FAIL，  1\" ））; 
 DropDownList drpResult =（DropDownList）row.FindControl（  ddlResult）; 

我在gridview下方有一个按钮，当我点击我想要访问的按钮并获得上述内容时下拉选择的值。如下面的代码里面点击事件

  foreach （GridViewRow row  in  gvMark.Rows）
 {
 DropDownList drpResult =（DropDownList）row.FindControl（  ddlResult）; 
 
  //  这里drpResult我的空白 
 
结果= drpResult.SelectedValue.ToString（）; 
} 

任何建议。在此先感谢..



我的尝试：



< pre lang =C＃> DropDownList ddlResult = new DropDownList（）;
ddlResult.ID = ddlResult;
ddlResult.AutoPostBack = true ;
ddlResult.SelectedIndexChanged + = ddlResult_SelectedIndexChanged;
ddlResult.Items.Insert（ 0 ， new ListItem（ PASS， 0\" ））;
ddlResult.Items.Insert（ 1 ， new ListItem（ FAIL， 1\" ））;
DropDownList drpResult =（DropDownList）row.FindControl（ ddlResult）;


foreach （GridViewRow row in gvMark.Rows）
{
DropDownList drpResult =（DropDownList）row.FindControl（ ddlResult） ;

// 这里drpResult我的空白

结果= drpResult.SelectedValue.ToString（）;
}

解决方案

您刚刚创建了一个DropDownList对象，但实际上并没有将它添加到GridView单元格中。所以你真的没办法在回发中访问它。此外，您可能需要在RowCreated事件中创建控件。这是一个工作代码供您参考：



ASPX

 <   asp：content     id   =  Content2   < span class =code-attribute> contentplaceholderid   =  MainContent    runat   =  server    xmlns：asp   =  ＃unknown >  
 <   asp：gridview     id   =  GridView1    runat   =  server    onrowcreated   =  GridView1_RowCreated >  
 <  列 >  
 <   asp：templatefield  >  
 <   itemtemplate  >  
 < span class =code-keyword>& lt;   asp：占位符    id   =  PlaceHolder1    runat   =  server >  <   / asp：占位符 >  
 <   / itemtemplate  >  
 <   / asp：templatefield  >  
 <   / columns  >  
 <   / asp：gridview   >  
 <   asp：button     id   =  Button1     runat   = < span class =code-keyword> server    onclick   =  Button1_Click    text   = 按钮    /  >  
 <   / asp：content  >  

背后的代码：

 使用系统; 
 使用 System.Web.UI.WebControls; 
 使用 System.Data; 
 
 命名空间 WebFormDemo 
 {
  public   partial   class  DynamicControlInGridView：System.Web.UI.Page 
 {
  protected   void  Page_Load（ object  sender，EventArgs e）{
  if （！IsPostBack）
 BindGridView（）; 
} 
 
  protected   void  GridView1_RowCreated（ object  sender，GridViewRowEventArgs e）{
  if （e.Row.RowType == DataControlRowType.DataRow）{
 DropDownList ddlResult =  new  DropDownList（）; 
 ddlResult.ID =   ddlResult; 
 ddlResult.Items.Insert（ 0 ， new  ListItem（  PASS，  0\" ））; 
 ddlResult.Items.Insert（ 1 ， new  ListItem（  FAIL，  1\" ））; 
 
 PlaceHolder p =（PlaceHolder）e.Row.FindControl（  PlaceHolder1）; 
 p.Controls.Add（ddlResult）; 
 
  //  您还可以将其添加到单元格集合中，如 
 TextBox tbox =  new  TextBox（）; 
 tbox.ID =   TextBox1; 
 e.Row.Cells [ 0 ]。Controls.Add（tbox）; 
 
} 
} 
 
  private   void  BindGridView（）{
 GridView1.DataSource = CreateDataSource（）; 
 GridView1.DataBind（）; 
} 
 
  public  DataTable CreateDataSource（）{
 DataTable dt = 新 DataTable（）; 
 DataRow博士; 
 
 dt.Columns.Add（ new  DataColumn（  ID， typeof （ string ）））; 
 dt.Columns.Add（ new  DataColumn（ 名称， typeof （ string ）））; 
 dt.Columns.Add（ new  DataColumn（ 姓氏， typeof （ string ）））; 
 
 dr = dt.NewRow（）; 
  //  为每列添加值 
 dr [  ID] =  1 ; 
 dr [ 名称] =    Vincent; 
 dr [  LastName] =    Durano; 
 dt.Rows.Add（dr）; 
  return  dt; 
} 
 
 受保护  void  Button1_Click（ object  sender，EventArgs e）{
  foreach （GridViewRow row  in  GridView1.Rows）{
 DropDownList dd1 =（DropDownList）row.FindControl（  ddlResult< /跨度>）; 
  if （dd1！=  null ）{
 Response.Write（ 找到DropDown！）; 
} 
 
 TextBox tbox = row.FindControl（  TextBox1） as  TextBox; 
  if （tbox！=  null ）{
 Response.Write（ 找到TextBox！）; 
} 
} 
 
} 
 
} 
} 

I've created dynamic dropdownlist in gridview rowdatabound pls refer below code.

DropDownList ddlResult = new DropDownList();
                    ddlResult.ID = "ddlResult";
                    ddlResult.AutoPostBack = true;
                    ddlResult.SelectedIndexChanged += ddlResult_SelectedIndexChanged; 
                    ddlResult.Items.Insert(0, new ListItem("PASS", "0"));
                    ddlResult.Items.Insert(1, new ListItem("FAIL", "1"));
DropDownList drpResult = (DropDownList)row.FindControl("ddlResult");

I've a button below the gridview, when i click the button i wants to access and get the above dropdown selected value. like below code inside click event

foreach (GridViewRow row in gvMark.Rows)
                {
DropDownList drpResult = (DropDownList)row.FindControl("ddlResult");
 
// Here "drpResult" i'm getting null

Result = drpResult.SelectedValue.ToString();
}

Any suggestion . thanks in advance..

What I have tried:

DropDownList ddlResult = new DropDownList();
                    ddlResult.ID = "ddlResult";
                    ddlResult.AutoPostBack = true;
                    ddlResult.SelectedIndexChanged += ddlResult_SelectedIndexChanged; 
                    ddlResult.Items.Insert(0, new ListItem("PASS", "0"));
                    ddlResult.Items.Insert(1, new ListItem("FAIL", "1"));
DropDownList drpResult = (DropDownList)row.FindControl("ddlResult");


foreach (GridViewRow row in gvMark.Rows)
                {
DropDownList drpResult = (DropDownList)row.FindControl("ddlResult");
 
// Here "drpResult" i'm getting null

Result = drpResult.SelectedValue.ToString();
}

解决方案

You just created a DropDownList object but you never add it to the GridView cells actually. So there's really no way for you to access it on postbacks. Also you may need to create the control at RowCreated event instead. Here's a working code for your reference:

ASPX

<asp:content id="Content2" contentplaceholderid="MainContent" runat="server" xmlns:asp="#unknown">
    <asp:gridview id="GridView1" runat="server" onrowcreated="GridView1_RowCreated">
        <columns>
                <asp:templatefield>
                    <itemtemplate>
                        <asp:placeholder id="PlaceHolder1" runat="server"></asp:placeholder>
                        </itemtemplate>
                </asp:templatefield>
         </columns>
    </asp:gridview>
    <asp:button id="Button1" runat="server" onclick="Button1_Click" text="Button" />
</asp:content>

CODE BEHIND:

using System;
using System.Web.UI.WebControls;
using System.Data;

namespace WebFormDemo
{
    public partial class DynamicControlInGridView : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e) {
            if (!IsPostBack)
                BindGridView();
        }

        protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e) {
            if (e.Row.RowType == DataControlRowType.DataRow) {
                DropDownList ddlResult = new DropDownList();
                ddlResult.ID = "ddlResult";
                ddlResult.Items.Insert(0, new ListItem("PASS", "0"));
                ddlResult.Items.Insert(1, new ListItem("FAIL", "1"));

                PlaceHolder p = (PlaceHolder)e.Row.FindControl("PlaceHolder1");
                p.Controls.Add(ddlResult);

                //you could also add it to the cells collection like
                TextBox tbox = new TextBox();
                tbox.ID = "TextBox1";
                e.Row.Cells[0].Controls.Add(tbox);

            }
        }

        private void BindGridView() {
            GridView1.DataSource = CreateDataSource();
            GridView1.DataBind();
        }

        public DataTable CreateDataSource() {
            DataTable dt = new DataTable();
            DataRow dr;

            dt.Columns.Add(new DataColumn("ID", typeof(string)));
            dt.Columns.Add(new DataColumn("Name", typeof(string)));
            dt.Columns.Add(new DataColumn("Lastname", typeof(string)));

            dr = dt.NewRow();
            //add values to each columns
            dr["ID"] = 1;
            dr["Name"] = "Vincent";
            dr["LastName"] = "Durano";
            dt.Rows.Add(dr);
            return dt;
        }

        protected void Button1_Click(object sender, EventArgs e) {
            foreach (GridViewRow row in GridView1.Rows) {
                DropDownList dd1 = (DropDownList)row.FindControl("ddlResult");
                if (dd1 != null) {
                    Response.Write("Found DropDown!");
                }

                TextBox tbox = row.FindControl("TextBox1") as TextBox;
                if (tbox != null) {
                    Response.Write("Found TextBox!");
                }
            }
           
        }
       
    }
}

这篇关于无法找到在gridview行中动态创建的dropdonlist控件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！