ASP .NET RowUpdating GridView 问题 [英] ASP .NET RowUpdating GridView Troubles

问题描述

我在使用 RowUpdating 方法时遇到问题.我的 GridView 已连接到我们本地的 SQL Server，我正在尝试更新数据.这是来自 MSDN 的 RowUpdating 方法的代码.

I'm having trouble with the RowUpdating Method. My GridView is connected to our local SQL Server, and I'm trying to update the data. Here is the code for the RowUpdating Method from MSDN.

protected void TaskGridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
        //Retrieve the table from the session object.
        DataTable dt = (DataTable)Session["TaskTable"];

        //Update the values.
        GridViewRow row = GridView1.Rows[e.RowIndex];
        dt.Rows[row.DataItemIndex]["Id"] = ((TextBox)(row.Cells[1].Controls[0])).Text;
        dt.Rows[row.DataItemIndex]["Description"] = ((TextBox)(row.Cells[2].Controls[0])).Text;
        dt.Rows[row.DataItemIndex]["IsComplete"] = ((CheckBox)(row.Cells[3].Controls[0])).Checked;

        //Reset the edit index.
        GridView1.EditIndex = -1;

        //Bind data to the GridView control.
        BindData();

}

我收到此错误:

System.NullReferenceException:未将对象引用设置为对象的实例.

System.NullReferenceException: Object reference not set to an instance of an object.

推荐答案

试试这个代码一次.

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];
    int id = Int32.Parse(GridView1.DataKeys[e.RowIndex].Value.ToString());
    TextBox tname = (TextBox)row.FindControl("nam");
    TextBox tques = (TextBox)row.FindControl("que");
    MySqlCommand cmd = new MySqlCommand("update exam set name1=@name,ques=@ques where id = @id", con);
    cmd.Parameters.Add("@id", MySqlDbType.Int16).Value = id;
    cmd.Parameters.Add("@name", MySqlDbType.VarChar, 30).Value = tname.Text.Trim();
    cmd.Parameters.Add("@ques", MySqlDbType.VarChar,40).Value = tques.Text.Trim();
    con.Open();
    cmd.ExecuteNonQuery();
    GridView1.EditIndex = -1;
    bind();
}

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