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(); } 如何实现忘记密码,回答一个问题后把密码自动发到你指定的邮箱的程序 asp.net button单击后的问题? 如何在Asp.net的Web服务器控件里使用AutoCompleteExtender 流程图插件问题 一个很菜的问题,请教大家 webparts作为后台可以随意的设置怎让设置好的后台在前台显示了 请大家访问数据库都用SqlHelper来做吗?还是自己写呀?SqlHelper有很多个版本吗?有帮助可以看的吗? Nhibernate的问题。 框架如何显示?? 怎样在datalist显示的数据上创建链接? 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();
}