我用这个code for exporting gridview to Excel in asp.net - c# .....但是我found some error in my code
我正在使用stored procedure作为sql command，我的代码如下。

C#代码加载事件(Calling GetData method)

   public partial class Admin_ResultDisplay : System.Web.UI.Page
   {
    SqlConnection cn;
    SqlCommand cmd = new SqlCommand();

    protected void Page_Load(object sender, EventArgs e)
    {
        cn = new SqlConnection(ConfigurationManager.ConnectionStrings["DbConnect"].ConnectionString);
        cn.Open();

        SqlCommand cmd = (SqlCommand)Session["sqlcmd"];
        DataTable dt = GetData(cmd);
        GridView1.DataSource = dt;
        GridView1.DataBind(); 
    }

private DataTable GetData(SqlCommand cmd)
{
    DataTable dt = new DataTable();
    String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["DbConnect"].ConnectionString;
    //SqlConnection cn = new SqlConnection(strConnString);
    SqlDataAdapter sda = new SqlDataAdapter();

    Session["sqlcmd"] = cmd;
    cmd.CommandType = CommandType.Text;  // <= ERROR POINTED HERE....
    cmd.Connection = cn;
    try
    {
        cn.Open();
        sda.SelectCommand = cmd;
        sda.Fill(dt);
        return dt;
    }
    catch (Exception ex)
    {
        throw ex;
    }
    finally
    {
        cn.Close();
        sda.Dispose();
        cn.Dispose();
    }
}

RAHUL:

最佳答案

这是因为您在按钮事件中定义了cmd，如下所示，它在作用域内是本地的。如果全局需要它，请尝试相应地进行定义。

protected void btn_insert_Click(object sender, EventArgs e)    
 {
 try
     {
         SqlCommand cmd = new SqlCommand("GetExamResults", cn); 

protected void Page_Load(object sender, EventArgs e) 
 {   
   cn = new SqlConnection(ConfigurationManager.ConnectionStrings     
   ["DbConnect"].ConnectionString);
   SqlCommand cmd = new SqlCommand("GetExamResults", cn);  

SqlCommand cmd = new SqlCommand();
// Your code goes here

Session["sqlcmd"] = cmd;

    protected void Page_Load(object sender, EventArgs e)
    {
        SqlCommand cmd = (SqlCommand)Session["sqlcmd"];

https://stackoverflow.com/questions/10484747/