是否可以同时使用多个sqldependency

是否可以同时使用多个sqldependency

本文介绍了是否可以同时使用多个sqldependency?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

限时删除!!

 string connection =我的连接字符串; 
string obj1;
public Form1()
{
InitializeComponent();

}
private void Form1_Load(object sender,EventArgs e)
{
Method1();
Method2();
}
private bool DoesUserHavePermission()
{
try
{
SqlClientPermission clientPermission = new
SqlClientPermission(PermissionState.Unrestricted);

clientPermission.Demand();

返回true;
}
捕获
{
返回false;
}
}
private void Method1()
{
try
{
if(!DoesUserHavePermission())
return ;
SqlDependency.Stop(连接);
SqlDependency.Start(connection);

使用(SqlConnection cn = new SqlConnection(connection))
{
if(cn.State == ConnectionState.Close)
cn.Open();
using(SqlCommand cmd = cn.CreateCommand())
{
cmd.Connection = cn;
cmd.CommandType = CommandType.Text;
cmd.CommandText =我的table1命令文本;
SqlDependency dep = new SqlDependency(cmd);
dep.OnChange + = new OnChangeEventHandler(dep_onchange1);
obj1 = cmd.ExecuteScalar()。ToString();
}
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
}
void dep_onchange1(对象发送者,SqlNotificationEventArgs e)
{
//一些事件
Method1();
SqlDependency dep = sender as SqlDependency;
dep.OnChange - = new OnChangeEventHandler(dep_onchange1);
}
private void Method2()
{
try
{
if(!DoesUserHavePermission())
return;
SqlDependency.Stop(连接);
SqlDependency.Start(connection);

使用(SqlConnection cn = new SqlConnection(connection))
{
if(cn.State == ConnectionState.Close)
cn.Open();
using(SqlCommand cmd = cn.CreateCommand())
{
cmd.Connection = cn;
cmd.CommandType = CommandType.Text;
cmd.CommandText =我的table2命令文本;
SqlDependency dep = new SqlDependency(cmd);
dep.OnChange + = new OnChangeEventHandler(dep_onchange2);
obj2 = cmd.ExecuteScalar()。ToString();
}
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
}
void dep_onchange2(object sender,SqlNotificationEventArgs e)
{
//某些事件
Method2();
SqlDependency dep = sender as SqlDependency;
dep.OnChange - = new OnChangeEventHandler(dep_onchange2);
}
private void Form1_Closing(object sender,FormClosingEventArgs e)
{
SqlDependency.Stop(connection);
}





我的尝试:



我想同时在两个或三个不同的表中使用SqlDependency.SqlDependency为一个表工作。没有问题。但是不能用于两个或三个不同的表。我可以做什么这样做吗?所以SqlDependency适用于[table1],但它不适用于[table1]和[table2]。只有一个工作。 
解决方案

string connection="My connection String";
string obj1;
public Form1()
{
   InitializeComponent();

}
private void Form1_Load(object sender, EventArgs e)
{
   Method1();
   Method2();
}
private bool DoesUserHavePermission()
 {
   try
   {
      SqlClientPermission clientPermission = new
      SqlClientPermission(PermissionState.Unrestricted);

      clientPermission.Demand();

      return true;
   }
   catch
   {
      return false;
   }
}
private void Method1()
{
try
 {
    if (!DoesUserHavePermission())
       return;
SqlDependency.Stop(connection);
SqlDependency.Start(connection);

using (SqlConnection cn = new SqlConnection(connection))
   {
     if(cn.State==ConnectionState.Close)
       cn.Open();
     using (SqlCommand cmd = cn.CreateCommand())
       {
         cmd.Connection=cn;
         cmd.CommandType = CommandType.Text;
         cmd.CommandText = "my command text for table1";
         SqlDependency dep = new SqlDependency(cmd);
         dep.OnChange += new OnChangeEventHandler(dep_onchange1);
         obj1=cmd.ExecuteScalar().ToString();
       }
    }
}
  catch (Exception ex)
  {
    MessageBox.Show(ex.Message);
  }
}
void dep_onchange1(object sender, SqlNotificationEventArgs e)
{
   //some events
   Method1();
   SqlDependency dep = sender as SqlDependency;
   dep.OnChange -= new OnChangeEventHandler(dep_onchange1);
}
private void Method2()
{
try
 {
    if (!DoesUserHavePermission())
       return;
SqlDependency.Stop(connection);
SqlDependency.Start(connection);

using (SqlConnection cn = new SqlConnection(connection))
   {
     if(cn.State==ConnectionState.Close)
       cn.Open();
     using (SqlCommand cmd = cn.CreateCommand())
       {
         cmd.Connection=cn;
         cmd.CommandType = CommandType.Text;
         cmd.CommandText = "my command text for table2";
         SqlDependency dep = new SqlDependency(cmd);
         dep.OnChange += new OnChangeEventHandler(dep_onchange2);
         obj2=cmd.ExecuteScalar().ToString();
       }
    }
}
  catch (Exception ex)
  {
    MessageBox.Show(ex.Message);
  }
}
void dep_onchange2(object sender, SqlNotificationEventArgs e)
{
   //some events
   Method2();
   SqlDependency dep = sender as SqlDependency;
   dep.OnChange -= new OnChangeEventHandler(dep_onchange2);
}
private void Form1_Closing(object sender, FormClosingEventArgs e)
 {
   SqlDependency.Stop(connection);
 }



What I have tried:

I want to use SqlDependency for two or three different tables at the same time.SqlDependency working for one table.No problem.But not working for two or three different tables.What can I do about this?So SqlDependency working for  [table1] but it is not working for [table1] and [table2].İt is working only one. 
解决方案


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09-07 03:04