Android如何通过代码获取cpu使用率

你可以通过以下代码获取Android设备的CPU使用率：

1. 首先，你需要获取设备当前的CPU使用情况：

private static final String TAG = "CpuUsage";
private static final int UPDATE_INTERVAL = 1000; // 更新间隔时间
private static long lastTotalCpuTime = 0;
private static long lastProcessCpuTime = 0;

public static float getCpuUsage() {
    float cpuUsage = 0.0f;

    long totalCpuTime = getTotalCpuTime();
    long processCpuTime = getProcessCpuTime();

    if (lastTotalCpuTime != 0) {
        long deltaTotalCpuTime = totalCpuTime - lastTotalCpuTime;
        long deltaProcessCpuTime = processCpuTime - lastProcessCpuTime;

        cpuUsage = deltaProcessCpuTime * 100.0f / deltaTotalCpuTime;
    }

    lastTotalCpuTime = totalCpuTime;
    lastProcessCpuTime = processCpuTime;

    return cpuUsage;
}

private static long getTotalCpuTime() {
    try {
        BufferedReader reader = new BufferedReader(new FileReader("/proc/stat"));
        String line;
        while ((line = reader.readLine()) != null) {
            if (line.startsWith("cpu ")) {
                String[] fields = line.split("\\s+");
                long totalCpuTime = 0;
                for (int i = 1; i < fields.length; i++) {
                    totalCpuTime += Long.parseLong(fields[i]);
                }
                return totalCpuTime;
            }
        }
    } catch (IOException e) {
        Log.e(TAG, "Failed to read /proc/stat", e);
    }
    return 0;
}

private static long getProcessCpuTime() {
    try {
        int pid = android.os.Process.myPid();
        BufferedReader reader = new BufferedReader(new FileReader("/proc/" + pid + "/stat"));
        String line = reader.readLine();
        String[] fields = line.split("\\s+");
        long utime = Long.parseLong(fields[13]);
        long stime = Long.parseLong(fields[14]);
        long cutime = Long.parseLong(fields[15]);
        long cstime = Long.parseLong(fields[16]);
        return utime + stime + cutime + cstime;
    } catch (IOException e) {
        Log.e(TAG, "Failed to read /proc/pid/stat", e);
    }
    return 0;
}

2. 然后，你需要使用一个定时器来定时获取CPU使用情况：

private Timer mTimer = new Timer();
private TimerTask mTimerTask = new TimerTask() {
    @Override
    public void run() {
        float cpuUsage = getCpuUsage();
        Log.d(TAG, "CPU Usage: " + cpuUsage);
    }
};

// 在onCreate()中启动定时器
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mTimer.schedule(mTimerTask, 0, UPDATE_INTERVAL);
}

// 在onDestroy()中停止定时器
@Override
protected void onDestroy() {
    super.onDestroy();
    mTimer.cancel();
}

这样，你就可以通过代码获取Android设备的CPU使用率了。