我的应用程序运行一些可能需要很长时间的数据库查询。
在执行这些查询时,我的应用程序似乎卡住了,看起来应用程序已停止工作。
我需要使用进度条来避免这个问题,但我不确定如何预测执行查询所需的时间。
运行查询的代码如下
private void CheckSsMissingDate()
{
while (DateTime.Parse(time) <= DateTime.Now)
{
var ssCon = OpenSQLConnection();
var cmd = new SqlCommand("SELECT TOP (1)Date_Time,Value1,Value2,Value3,Value4,Value5,Value6,
"+ "Value7,Value8,Value9 from RAW_S001T01 where Date_Time >='" + tempTime + "'",ssCon);
var dr = cmd.ExecuteReader();
var count = 0;
while (dr.Read())
{
ssChkDate = (dr["Date_Time"].ToString());
conssChkDate = DateTime.Parse(ssChkDate).ToString("yyyy-MM-dd HH:mm:ss");
tempTime = Convert.ToDateTime(ssChkDate);
tempTime = tempTime.AddMinutes(15);
TValue1 = (dr["Value1"].ToString());
TValue2 = (dr["Value2"].ToString());
TValue3 = (dr["Value3"].ToString());
TValue4 = (dr["Value4"].ToString());
TValue5 = (dr["Value5"].ToString());
TValue6 = (dr["Value6"].ToString());
TValue7 = (dr["Value7"].ToString());
TValue8 = (dr["Value8"].ToString());
TValue9 = (dr["Value9"].ToString());
if (CheckMsMissingDate(conssChkDate) == false)
{
InsertMissing(conssChkDate,TValue1,TValue2,TValue3,TValue4,TValue5,TValue6,TValue7,TValue8,TValue9);
count = count + 1;
}
}
dr.Close();
ssCon.Close();
updateCount.Text = count + @" Missing Records added.";
}
}
如何显示进度条来显示查询的进度?
最佳答案
你可以使用BackgroundWorker()
来解决这类问题。
首先定义一个BackgroundWorker()
类的全局变量
喜欢
private BackgroundWorker bgw;
然后使用下面的代码开始您的查询执行,例如 button1_Click()
事件或任何其他内容。
bgw = new BackgroundWorker();
bgw.WorkerReportsProgress = true;
bgw.ProgressChanged += new ProgressChangedEventHandler(bgw_ProgressChanged);
bgw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bgw_RunWorkerCompleted);
bgw.DoWork += new DoWorkEventHandler(bgw_DoWork);
bgw.RunWorkerAsync();
现在定义方法如下:
void bgw_DoWork(object sender, DoWorkEventArgs e)
{
//Your time taking work. Here it's your data query method.
CheckSsMissingDate();
}
void bgw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
//Progress bar.
progressBar1.Value = e.ProgressPercentage;
}
void bgw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
//After completing the job.
MessageBox.Show(@"Finished");
}
关于c# - C#中长时间运行任务的进度条,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20759386/