一点点的源码··我以前也做过··

float cpuData = 0; // Cpu

                float Meming = 0; // 内存

                ManagementObjectSearcher searcher = new ManagementObjectSearcher("Select * From Win32_Process Where ParentProcessID=" + Global.process.Id);

                ManagementObjectCollection moc = searcher.Get();

                foreach (ManagementObject mo in moc) {

                    Process p = Process.GetProcessById(Convert.ToInt32(mo["ProcessID"]));

                    Meming += p.WorkingSet64  / 1024 / 1024; // 内存的用量

                    PerformanceCounter proccessCpu = new PerformanceCounter("Process", "% Processor Time", p.ProcessName);

                    cpuData += proccessCpu.NextValue() / Environment.ProcessorCount; // CPU的使用率

                }