用CString强制清空函数与直接写0方法 速度对比

 CString str[200];LARGE_INTEGER liFreq,liStart,liEnd;int i;for (i=0;i<200;i++)    //先赋值,分配一下内存{str[i] = "abc";}QueryPerformanceFrequency(&liFreq);QueryPerformanceCounter(&liStart);for (i=0;i<200;i++){str[i].Empty();}QueryPerformanceCounter(&liEnd);double fCount = liEnd.QuadPart - liStart.QuadPart;TRACE("直接Empty用时____%.10f 秒\n",fCount/liFreq.QuadPart);QueryPerformanceCounter(&liStart);for (i=0;i<200;i++){str[i] = "";}QueryPerformanceCounter(&liEnd);fCount = liEnd.QuadPart - liStart.QuadPart;TRACE("写0清零用时______%.10f 秒\n",fCount/liFreq.QuadPart);

显示结果

直接Empty用时____0.0003964411 秒
写0清零用时______0.0000331363 秒
直接Empty用时____0.0008400491 秒
写0清零用时______0.0000704519 秒
直接Empty用时____0.0008397506 秒
写0清零用时______0.0000707504 秒
直接Empty用时____0.0008406462 秒
写0清零用时______0.0000704519 秒