GridView不包含“列”的定义，也没有可以找到接受“GridView”类型的第一个参数的扩展方法“Columns” [英] GridView does not contain a definition for 'Columns' and no extension method 'Columns' accepting a first argument of type 'GridView' could be found
问题描述
复制我的aspx&后出现上述错误cs文件到.NET framework 4.0。因为表单最初是在.NET framework 2.0上开发的。不得不将其复制到框架4.0，因为我需要在项目中使用图表控件。我运行了页面并得到了结果
***编译器错误消息：CS1061：'GridView'不包含'Columns'的定义，没有可以找到接受GridView类型的第一个参数的扩展方法Columns（你是否缺少using指令或汇编引用？）***
这是cs文件的完整源代码
使用系统;
使用 System.Collections.Generic;
// 使用System.Linq;
使用 System.Web;
使用 System.Web.UI;
使用 System.Web.UI.WebControls;
使用 System.Security.Principal;
使用 System.Data.SqlClient;
使用 System.Data;
public partial class 调查：System.Web.UI.Page
{
string responder = WindowsIdentity.GetCurrent（）。Name.ToString（）;
int catID;
int qID;
int canteenID;
string 响应;
string 条评论;
string 评论;
string responseDate = DateTime.Now.ToShortDateString（）。ToString（）;
SqlDataSource sds1 = new SqlDataSource（）;
// SqlDataSource sds2 = new SqlDataSource（）;
受保护 void Page_Init（对象发件人，EventArgs e）
{
// set dataSource properties
sds1.ConnectionString = 数据源= BNY-D-1245;初始目录= canteenSurvey;集成安全=真;
sds1.ProviderName = System.Data.SqlClient;
// sds2.ConnectionString =数据源= BNY-D-1245;初始目录= canteenSurvey; Integrated Security = True;
// sds2.ProviderName =System。 Data.SqlClient;
// 将数据源绑定到页面
sds1.DataBind（）;
// sds2.DataBind（）;
}
< span class =code-keyword> protected void Page_Load（ object sender，EventArgs e ）
{
}
受保护 void gvCategory_PreRender （ object sender，EventArgs e）
{
foreach （GridViewRow item gvCategory.Rows中的class =code-keyword>
{
catID =（ int ）gvCategory.DataKeys [item .RowIndex]。价值;
GridView gvQuestion =（GridView）item.FindControl（ gvQuestion） ;
sds1.SelectCommand = SELECT * FROM tblQuestion WHERE [CatID] = + catID;
gvQuestion.Columns [ 0 ]。可见= true ;
gvQuestion.DataSource = sds1;
gvQuestion.DataBind（）;
gvQuestion.Columns [ 0 ]。可见= false ;
foreach （GridViewRow row in gvQuestion.Rows）
{
qID =（ int ）gvQuestion.DataKeys [row.RowIndex] .Value;
}
}
}
受保护 void btnSubmit_Click（ object sender，EventArgs e）
{
foreach （GridViewRow masterItem in gvCategory.Rows）
{
catID =（ INT ）gvCategory.DataKeys [masterItem.RowIndex]。价值;
GridView gvQuestion =（GridView）masterItem.FindControl（ gvQuestion） ;
foreach （GridViewRow masterRow in gvQuestion.Rows）
{
qID =（ int ）gvQuestion.DataKeys [masterRow.RowIndex] .Value;
GridView gvCanteen =（GridView）masterRow.FindControl（ gvCanteen） ;
foreach （GridViewRow masterData in gvCanteen.Rows）
{
canteenID =（ int ）gvCanteen.DataKeys [masterData.RowIndex] .Value;
response =（（DropDownList）masterData.FindControl（ ddlResponse））。SelectedValue;
comments = txtComments.Text;
// 插入数据库
string constr = 数据源= BNY-D-1245;初始目录= canteenSurvey; Integrated Security = True;
// 用于将值插入数据库的SQL查询
string sqlQuery = INSERT INTO tblFeedBack（ catID，qID，canteenID，responseID，responder，responseDate）;
sqlQuery + = VALUES（@ catID，@ qID，@ scanidID，@ responseID，@ response，@ responseDate）;
// string sqlQuery2 =INSERT INTO tblComments（responder，comments）VALUES（@responder） ，@ comment）;
// SqlCommand query = new SqlCommand（ ）;
使用（SqlConnection dataConnection = new SqlConnection（constr））
{
使用（SqlCommand dataCommand = dataConnection.CreateCommand（））
{
dataConnection.Open（）;
dataCommand.CommandType = CommandType.Text;
dataCommand.CommandText = sqlQuery;
dataCommand.Parameters.AddWithValue（ @ catID，catID）;
dataCommand.Parameters.AddWithValue（ @ qID，qID）;
dataCommand.Parameters.AddWithValue（ @ canteenID，canteenID）;
dataCommand.Parameters.AddWithValue（ @ responseID，response）;
dataCommand.Parameters.AddWithValue（ @ responder，responder）;
dataCommand.Parameters.AddWithValue（ @ responseDate，responseDate）;
dataCommand.ExecuteNonQuery（）;
dataConnection.Close（）;
}
}
}
}
}
}
}
引用：此代码效果很好在.NET 2.0框架中。不得不将aspx和cs文件复制到.NET 4.0框架，因为我已经实现了图表，并且图表可以用于调查问题。
我也是删除整个文件并在4.0 .NET框架上重新创建，我仍然得到相同的错误。所有的帮助将在解决这个问题时表示赞赏。
谢谢大家。
我在代码的这一部分得到以下错误：
Quote：gvQuestion .Columns [0] .Visible = true;
gvQuestion.DataSource = sds1;
gvQuestion.DataBind（）;
gvQuestion.Columns [0] .Visible = false;
Quote：
gvQuestion.Columns [ 0 ]。可见= true ;
gvQuestion.DataSource = sds1;
gvQuestion.DataBind（）;
gvQuestion.Columns [ 0 ]。可见= false ;
第一行会产生问题，因为GridView还没有限制。
下一个问题可能是 -GridView.Columns.Count在GridView中设置AutoGenerateColumns =true时为0。
如果你想隐藏GridView的第一列，那么你也可以在里面尝试RowDataBoundevent。
protected void gvQuestion_RowDataBound（ object sender，GridViewRowEventArgs e）
{
e.Row.Cells [ 0 ]。可见= false ;
}
I got the above error after copying my aspx & cs files to .NET framework 4.0. as the form was originally developed on .NET framework 2.0. Had to copy it over to framework 4.0 because I needed to use chart controls in the project. I ran the page and got the result
***Compiler Error Message: CS1061: 'GridView' does not contain a definition for 'Columns' and no extension method 'Columns' accepting a first argument of type 'GridView' could be found (are you missing a using directive or an assembly reference?)***
This is the entire source code to the cs file
using System;
using System.Collections.Generic;
//using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Principal;
using System.Data.SqlClient;
using System.Data;
public partial class Survey : System.Web.UI.Page
{
string responder = WindowsIdentity.GetCurrent().Name.ToString();
int catID;
int qID;
int canteenID;
string response;
string comments;
string comment;
string responseDate = DateTime.Now.ToShortDateString().ToString();
SqlDataSource sds1 = new SqlDataSource();
//SqlDataSource sds2 = new SqlDataSource();
protected void Page_Init(object sender, EventArgs e)
{
// set dataSource properties
sds1.ConnectionString = "Data Source=BNY-D-1245;Initial Catalog=canteenSurvey;Integrated Security=True";
sds1.ProviderName = "System.Data.SqlClient";
//sds2.ConnectionString = "Data Source=BNY-D-1245;Initial Catalog=canteenSurvey;Integrated Security=True";
//sds2.ProviderName = "System.Data.SqlClient";
// bind datasource to page
sds1.DataBind();
//sds2.DataBind();
}
protected void Page_Load(object sender, EventArgs e)
{
}
protected void gvCategory_PreRender(object sender, EventArgs e)
{
foreach (GridViewRow item in gvCategory.Rows)
{
catID = (int)gvCategory.DataKeys[item.RowIndex].Value;
GridView gvQuestion = (GridView)item.FindControl("gvQuestion");
sds1.SelectCommand = "SELECT * FROM tblQuestion WHERE [CatID] = " + catID;
gvQuestion.Columns[0].Visible = true;
gvQuestion.DataSource = sds1;
gvQuestion.DataBind();
gvQuestion.Columns[0].Visible = false;
foreach (GridViewRow row in gvQuestion.Rows)
{
qID = (int)gvQuestion.DataKeys[row.RowIndex].Value;
}
}
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
foreach (GridViewRow masterItem in gvCategory.Rows)
{
catID = (int)gvCategory.DataKeys[masterItem.RowIndex].Value;
GridView gvQuestion = (GridView)masterItem.FindControl("gvQuestion");
foreach (GridViewRow masterRow in gvQuestion.Rows)
{
qID = (int)gvQuestion.DataKeys[masterRow.RowIndex].Value;
GridView gvCanteen = (GridView)masterRow.FindControl("gvCanteen");
foreach (GridViewRow masterData in gvCanteen.Rows)
{
canteenID = (int)gvCanteen.DataKeys[masterData.RowIndex].Value;
response = ((DropDownList)masterData.FindControl("ddlResponse")).SelectedValue;
comments = txtComments.Text;
// Insert into the database
string constr = "Data Source=BNY-D-1245;Initial Catalog=canteenSurvey;Integrated Security=True";
// SQL Query to insert values into the database
string sqlQuery = "INSERT INTO tblFeedBack (catID, qID, canteenID, responseID, responder, responseDate)";
sqlQuery += "VALUES (@catID, @qID, @canteenID, @responseID, @responder, @responseDate )";
//string sqlQuery2 = "INSERT INTO tblComments (responder, comments) VALUES (@responder, @comments)";
//SqlCommand query = new SqlCommand();
using (SqlConnection dataConnection = new SqlConnection(constr))
{
using (SqlCommand dataCommand = dataConnection.CreateCommand())
{
dataConnection.Open();
dataCommand.CommandType = CommandType.Text;
dataCommand.CommandText = sqlQuery;
dataCommand.Parameters.AddWithValue("@catID", catID);
dataCommand.Parameters.AddWithValue("@qID", qID);
dataCommand.Parameters.AddWithValue("@canteenID", canteenID);
dataCommand.Parameters.AddWithValue("@responseID", response);
dataCommand.Parameters.AddWithValue("@responder", responder);
dataCommand.Parameters.AddWithValue("@responseDate", responseDate);
dataCommand.ExecuteNonQuery();
dataConnection.Close();
}
}
}
}
}
}
}
Quote:This code works well in .NET 2.0 framework. Had to copy the aspx and the cs files to .NET 4.0 framwork because I have implemented chart and the chart is mearnt to work with the survey questions.
I hve also deleted the entire file and recreated same on the 4.0 .NET framework and I still get same error. All help would be appreciated in resolving this issue.
Thanks Guys.
I get the below error in this section of the code:
Quote:gvQuestion.Columns[0].Visible = true;
gvQuestion.DataSource = sds1;
gvQuestion.DataBind();
gvQuestion.Columns[0].Visible = false;
Quote:
gvQuestion.Columns[0].Visible = true;gvQuestion.DataSource = sds1; gvQuestion.DataBind(); gvQuestion.Columns[0].Visible = false;The first line would create problem because GridView is not yet bounded.
Next problem might be -GridView.Columns.Countwill be 0 when you setAutoGenerateColumns="true"in yourGridView.
As you want to hide the first column ofGridView, then you can also try insideRowDataBoundevent.
protected void gvQuestion_RowDataBound(object sender, GridViewRowEventArgs e) { e.Row.Cells[0].Visible = false; }
这篇关于GridView不包含“列”的定义，也没有可以找到接受“GridView”类型的第一个参数的扩展方法“Columns”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！
