Question

您好朋友我正在尝试在asp.net中开发一个喊话框，但它以错误结束连接未关闭。连接的当前状态是开放的。你能帮我解决一下代码中的问题。

Shout.aspx.cs

using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace finalWork
{
    public partial class Shout : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                PopulateTextBox();
            }
        }
        private void PopulateTextBox()
        {
            SqlConnection con = ConnectionManager.GetDatabaseConnection();
            DataTable dt = new DataTable();
            string name = string.Empty, message = string.Empty;
            StringBuilder sb = new StringBuilder(string.Empty);
            try
            {
                con.Open();
                string sqlStatement = "SELECT * FROM Message";
                SqlCommand cmd = new SqlCommand(sqlStatement, con);
                SqlDataAdapter sqlDa = new SqlDataAdapter(cmd);
                sqlDa.Fill(dt);
                if (dt.Rows.Count > 0)
                {
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        //get the data stored from the DataTable
                        name = dt.Rows[i]["Username"].ToString();// where Name is the FieldName from database
                        message = dt.Rows[i]["Message"].ToString();
                        sb.AppendFormat("Name:{0}Date Posted:{1}{2}", name + Environment.NewLine
                                               , DateTime.Now.ToShortDateString() + Environment.NewLine
                                               , message + Environment.NewLine);
                    }
                    // get the concated and formatted values from string builder and display the result in TextBoxPrintMessage

                    TextBoxPrintMessage.Text = sb.ToString();
                }
                con.Close();
            }
            catch (System.Data.SqlClient.SqlException ex)
            {
                string msg = "Fetch Error:";
                msg += ex.Message;
                throw new Exception(msg);
            }
            finally
            {
                con.Close();
            }
        }

        private void AddNewPost(string name, string message)
        {

            SqlConnection con = ConnectionManager.GetDatabaseConnection();
            string sqlStatement = string.Empty;

            sqlStatement = "INSERT INTO Message" +
                           "(Username,Message)" +
                           "VALUES (@Username,@Message)";
            try
            {
                con.Open();
                SqlCommand cmd = new SqlCommand(sqlStatement, con);
                cmd.Parameters.AddWithValue("@Username", name);
                cmd.Parameters.AddWithValue("@Message", message);
                cmd.CommandType = CommandType.Text;
                cmd.ExecuteNonQuery();
            }
            catch (System.Data.SqlClient.SqlException ex)
            {
                string msg = "Insert Error:";
                msg += ex.Message;
                throw new Exception(msg);
            }
            finally
            {
                con.Close();
            }
        }

        protected void ButtonPost_Click(object sender, EventArgs e)
        {
            // Check for empty values fieds before inserting the record
            if (TextBoxName.Text != string.Empty && TextBoxMessage.Text != string.Empty)
            {
                //insert new post to database
                AddNewPost(TextBoxName.Text.Trim(), TextBoxMessage.Text.Trim());
                //Populate the TextBox to reflect changes made
                PopulateTextBox();
            }
            else
            {
                //display message if the field was not supplied
                Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "Script",
                "alert('Please supply the required  fields!');", true);
            }
        }



    }
}

Answer 1

我只需手动添加它就可以了：）

 string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
 SqlConnection con = new SqlConnection(constr);

Answer 2

尝试这种方式。它会对你有所帮助。

SqlConnection connection = new SqlConnection(youCconnectionString);
connection.Close(); 
connection.Open();
SqlCommand command = new SqlCommand("YourQuery", connection);
command.CommandType = CommandType.Text;
command.ExecuteNonQuery();
connection.Close();
command.Dispose();

Answer 3

在下面的代码中添加注释，它已在PopulateTextBox（）函数的finally块中调用。

//con.Close();

Answer 4

删除con.Close（）;在Try块中，因为你在finally块中使用它。

连接已打开，未在asp.net中关闭

4 个答案: