“SqlTransaction 已完成;它再也无法使用”解决方法

大家好，又见面了，我是你们的朋友全栈君。当只是使用一次事务时，只用简单的事务就可以了

示例代码：

       SqlServerDataBase obj = new SqlServerDataBase();
        SqlConnection conn = obj.DBconn();
        conn.Open();
        SqlTransaction myTrans;
        myTrans = conn.BeginTransaction(IsolationLevel.ReadCommitted);

        try
        {

            obj.Insert(“insert into StuInfo (StuNumber,Name,Sex,Specialty) values(‘” + stuNumber + “‘,'” + name + “‘,'” + sex + “‘,'” + specialty + “‘)”, null);
            obj.Insert(“insert into StuSkill(StuNumber,Skill) values(‘” + stuNumber + “‘,'” + skill + “‘)”, null);
            myTrans.Commit();
            Response.Write(“两条数据均插入到数据库中！”);
        }
        catch (Exception ex)
        {

            try
            {

                myTrans.Rollback();
            }
            catch (SqlException sqlEx)
            {

                if (obj.DBconn() != null)
                {

                    Response.Write(sqlEx.GetType()+”数据库打开失败”);
                    Response.Redirect(“submit.htm”);
                }
            }
        }
        finally
        {

            obj.DBconn().Close();
        }

但是设计多个事务处理，比方使用for循环时，处理不当就会产生“SqlTransaction 已完成;它再也无法使用”的问题，主要就是因为SqlTransaction 使用了Commit()后就是不能在使用了，必须重新BeginTransaction()一个。

批处理事务不应该把transaction事务放在for循环里，造成多个事务，这将导致错误.
应该把for放在transaction里，当成一个事务来处理，进行批处理

示例代码：

protected void btnDelete_Click(object sender, EventArgs e) //删除
    {

        SqlServerDataBase del = new SqlServerDataBase();
        string str = “”;
        SqlConnection conn = del.DBconn();
        conn.Open();
        SqlTransaction myTrans;
        myTrans = conn.BeginTransaction(IsolationLevel.ReadCommitted);

        ListBox1.Items.Clear();
        try
        {

            for (int i = 0; i < GridView1.Rows.Count; i++) //从GridView中选中checkbox
            {

                GridViewRow row = GridView1.Rows[i];
                bool isChecked = ((CheckBox)row.FindControl(“chkSelect”)).Checked;
                if (isChecked)
                {

                    ListBox1.Items.Add(GridView1.Rows[i].Cells[2].Text);
                    //Column 1 is the StuNumber column
                    str = GridView1.Rows[i].Cells[1].Text; //获取删除行的StuNumber的值
                    // Response.Write(str.ToString());
                    del.Delete(“delete from StuInfo where StuNumber = ‘” + str + “‘”, null);
                    del.Delete(“delete from StuSkill where StuNumber = ‘” + str + “‘”, null);//删除
                }

            }
            myTrans.Commit();
         }
        catch (Exception ex)
        {

            try
            {

                myTrans.Rollback();
            }
            catch (SqlException sqlEx)
            {

                if (del.DBconn() != null)
                {

                    Response.Write(sqlEx.GetType() + “数据库打开失败”);
                    Response.Redirect(“submit.htm”);
                }
            }
        }
        finally
        {

            conn.Close();
        }
        BindData();
    }
}