在vb.net里通过什么方法可以实时的检测到数据库的变化?? 如题,比如SQLSERVER里的一张表,里面加入一条数据以后,程序可以立刻检测到,并且做出相应的反映。好心人帮忙给点意见吧! 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 private System.Threading.Timer t1 = null;public DataChecker() { // // Required for Windows Form Designer support // InitializeComponent(); // // TODO: Add any constructor code after InitializeComponent call // t1 = new System.Threading.Timer(new TimerCallback(Timer_Callback), 'C', 0, 500); } protected void Timer_Callback(object state) { ThreadPool.QueueUserWorkItem(new WaitCallback(GetData), state); } int retVal; private void GetData(object type) { char priceType = (char)type; string sql = null; sql = "SELECT Price FROM tblPrices WHERE Type='"+priceType.ToString()+"'"; SqlConnection cn = new SqlConnection("Server=localhost; Database=Prices; Integrated Security=SSPI"); cn.Open(); SqlCommand cmd = new SqlCommand(sql, cn); lock(this) { retVal = (int)cmd.ExecuteScalar(); switch(priceType) { case 'C': lastCoffeePrice = Convert.ToInt32(txtCoffeePrice.Text); txtCoffeePrice.Text = retVal.ToString(); break; case 'T': lastTeaPrice = Convert.ToInt32(txtTeaPrice.Text); txtTeaPrice.Text = retVal.ToString(); break; case 'G': lastGoldPrice = Convert.ToInt32(txtGoldPrice.Text); txtGoldPrice.Text = retVal.ToString(); break; } } allUpdates++; cn.Close(); } 在线求教 httpHandler 处理网站部分图片 巨大问题。 .net mvc中多个Remote数据验证 asp.net页面中如何直接拖放控件? 急!!客户端打印的问题 100分水晶报表打印的解决方案。先到先得分.顺便散散分. linkButton 各位高手帮我解决一下 在线等待回答关于连接数据库的问题: 怎样等待几秒钟 孟子e章中的"将DataGrid输出到Excel文件 "怎么调试失败? 请问aspnet怎么显示messagebox之类的提示框 DataGrid的问题 有没有办法解决事件丢失的问题
public DataChecker()
{
//
// Required for Windows Form Designer support
//
InitializeComponent(); //
// TODO: Add any constructor code after InitializeComponent call
// t1 = new System.Threading.Timer(new TimerCallback(Timer_Callback), 'C', 0, 500);
} protected void Timer_Callback(object state)
{
ThreadPool.QueueUserWorkItem(new WaitCallback(GetData), state);
}
int retVal;
private void GetData(object type)
{
char priceType = (char)type;
string sql = null; sql = "SELECT Price FROM tblPrices WHERE Type='"+priceType.ToString()+"'"; SqlConnection cn = new SqlConnection("Server=localhost; Database=Prices; Integrated Security=SSPI");
cn.Open(); SqlCommand cmd = new SqlCommand(sql, cn);
lock(this)
{
retVal = (int)cmd.ExecuteScalar();
switch(priceType)
{
case 'C':
lastCoffeePrice = Convert.ToInt32(txtCoffeePrice.Text);
txtCoffeePrice.Text = retVal.ToString();
break;
case 'T':
lastTeaPrice = Convert.ToInt32(txtTeaPrice.Text);
txtTeaPrice.Text = retVal.ToString();
break;
case 'G':
lastGoldPrice = Convert.ToInt32(txtGoldPrice.Text);
txtGoldPrice.Text = retVal.ToString();
break;
}
}
allUpdates++;
cn.Close();
}