在GridView中添加删除更新 [英] Add Delete Update in gridview

问题描述

你好朋友，
我正在尝试使用CommandField从网格中删除记录.我已经在gridview RowDeleting方法中编写了以下用于删除的代码:

Hello friends,
I''m trying to delete record from grid using CommandField. I have written the following code for delete in gridview RowDeleting method:

protected void gv_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        Label lblUserId = new Label();
        lblUserId .Text = ((Label)gv.SelectedRow.FindControl("lblId")).Text; //Line2
        SqlCommand objCmd = new SqlCommand("delete from tbl_user where user_id =" + lblUserId.Text, objCon);
        objCmd.ExecuteNonQuery();
        GvDataBind();
    }

我在第2行出现错误，说:

I''m getting error at line 2 saying:

Object reference not set to an instance of an object.

我有支票

I have check

gv.SelectedRow

它给出了空值

任何人都可以帮忙，我哪里做错了. . ?

在此先感谢

it is giving null value

Can anyone help, where I''m going wrong. . ?

Thanks in Advance

推荐答案

在该行上放置一个调试点.检查哪个值是空的.
很有可能找不到lblId ，并且当您尝试访问其text属性时，代码将引发错误.

Put a debug point on that line. Check which of the values is null.
In all probability, lblId is not being found and when you try to access its text property, code throws an error.

这是什么?

what is it?

Label lblUserId = new Label();
// lblUserId .Text = ((Label)gv.SelectedRow.FindControl("lblId")).Text; //Line2

string Id = ((GridView)sender).DataKeys[e.RowIndex].Value.ToString();
SqlCommand objCmd = new SqlCommand("delete from tbl_user where user_id =" + Id, objCon);

另一种方式:

another way:

CommandName = "Delete" CommandArgument="<%# ((GridViewRow) Container).RowIndex%>"

if(e.CommandName.ToUpper("DELETE"))
{
  int Id = Convert.ToInt32(e.CommandArgument);
  SqlCommand objCmd = new SqlCommand("delete from tbl_user where user_id =" + Id.ToString(), objCon);

最后我做到了:

Finally i have done it:

string Id = ((Label)gv.Rows[e.RowIndex].FindControl("lblId")).Text;
        SqlCommand objCmd = new SqlCommand("delete from tbl_user where user_id = @Id", objCon);
        objCmd.Parameters.AddWithValue("@Id", Id);

经过长时间的搜索，这就是我想要的.

After long search, this is what i was looking for.

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