C# 获取任务执行时间

 [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
    static extern bool QueryPerformanceCounter(ref long count);

    [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
    static extern bool QueryPerformanceFrequency(ref long count);

private void TreatSub()
{

long count = 0;
        long count1 = 0;
        long freq = 0;
        double result = 0;

        QueryPerformanceFrequency(ref freq);
        QueryPerformanceCounter(ref count);

        //需要测试的模块，及需要获取执行时间的执行过程
        JiraPost.RequestBugStat req = new JiraPost.RequestBugStat();
        req.chartType = "bugType";
        req.project = "Demo";
        req.version = "";
        req.pageCount = TextBox2.Text;

        DataTable dt = JiraGet.GetBugTablesJira.GetBugTable(req);

        //
        QueryPerformanceCounter(ref count1);
        count = count1 - count;
        result = (double)(count) / (double)freq;

}