连接C#和SQL Server 2008 R2 [英] connection c# and SQL server 2008 R2

问题描述

大家好，
请我有一个小问题，hier是我的代码.此代码遍历，但我不能给出多个数据(或信息).之后，我需要关闭WinForm并再次运行.问题出在哪儿?有人可以帮我吗.

Hey Every Body,
please Ihave a small problem, hier is my code. This code walk but i cannot give more than one data(or Informations). after that i need to close my WinForm and run it again. where is the Problem? can somed´body help me please.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data.Common;


namespace Netz_Vorgang
{
    public partial class Form1 : Form
    {
        SqlConnection connection = new SqlConnection("Data Source=STEPHANE-YOTAT\\STEPHANE;Initial Catalog=DBtest;Trusted_Connection=Yes");
        public Form1()
        {
            InitializeComponent();
            try
            {
                connection.Open();
            }
            catch (Exception ex)
            {
                MessageBox.Show("error occured 2 " + ex.Message);
                this.Dispose();
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
        }

        private void _insert_Click(object sender, EventArgs e)
        {
   

            string com = string.Format("insert into Step values('{0}', '{1}')", (string)(_StepName.Text.ToString()), Int32.Parse(_Dauer.Text));

            SqlCommand com2 = new SqlCommand(com,connection);
            try
            {
                com2.ExecuteNonQuery();
                connection.Dispose();
                MessageBox.Show("successfull");
                _StepName.Text.Equals( "");
                _Dauer.Text = "";
                _StepName.Focus();
                
                this.Update();
            }
            catch (Exception ex)
            {
                MessageBox.Show("error occured 1" + ex.Message);
                this.Dispose();
            }
        }

        private void _show_Click(object sender, EventArgs e)
        {
            SqlCommand connec = new SqlCommand("select * from Table",connection);
            DataSet vds = new DataSet();
            SqlDataAdapter vda = new SqlDataAdapter(connec);
            vda.Fill(vds,"ret");
            dataGridView1.DataSource = vds.Tables["ret"];
            connection.Dispose();
            
        }
    }
}

如果有人有其他解决方案，请妥善处理.感谢您的帮助.

Please if somebody have another Solution it wellcome. Thanks for ur Help.

推荐答案

不要在表单构造函数中进行connection.open操作.在进行任何操作之前先进行操作，然后确保将其关闭.

仅在窗体关闭时才设置连接，否则关闭连接应该没问题.

Dont do a connection.open in form constructor. do it before any operation and then make sure to close it.

Dispose the connection only when form closes else closing the connection should be fine.

在_show_Click方法中，您要设置连接-onnection.Dispose();.
从代码中删除该行.

In the _show_Click method, you are disposing off your connection - onnection.Dispose();.
Remove that line from your code.

谢谢.它走得很完美.

最好的问候.

thanks guy. it walk perfectly.

Best regards.

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