Android获取当前进程CPU使用率的方法

可以通过以下方法来获取Android当前进程CPU使用率：

1. 获取当前进程ID：

int pid = android.os.Process.myPid();

2. 获取当前进程CPU使用时间：

long cpuTime = 0;
RandomAccessFile reader = null;
try {
    reader = new RandomAccessFile("/proc/" + pid + "/stat", "r");
    String line = reader.readLine();
    String[] arr = line.split("\\s+");
    cpuTime = Long.parseLong(arr[13]) + Long.parseLong(arr[14]);
} catch (IOException e) {
    e.printStackTrace();
} finally {
    if (reader != null) {
        try {
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

3. 获取系统总CPU使用时间：

long totalCpuTime1 = 0;
long idleCpuTime1 = 0;
RandomAccessFile cpuReader = null;
try {
    cpuReader = new RandomAccessFile("/proc/stat", "r");
    String cpuLine = cpuReader.readLine();
    String[] cpuArr = cpuLine.split("\\s+");
    for (int i = 2; i < cpuArr.length; i++) {
        totalCpuTime1 += Long.parseLong(cpuArr[i]);
    }
    idleCpuTime1 = Long.parseLong(cpuArr[4]);
} catch (IOException e) {
    e.printStackTrace();
} finally {
    if (cpuReader != null) {
        try {
            cpuReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

4. 计算当前进程CPU使用率：

long totalCpuTime2 = 0;
long idleCpuTime2 = 0;
RandomAccessFile cpuReader2 = null;
try {
    cpuReader2 = new RandomAccessFile("/proc/stat", "r");
    String cpuLine2 = cpuReader2.readLine();
    String[] cpuArr2 = cpuLine2.split("\\s+");
    for (int i = 2; i < cpuArr2.length; i++) {
        totalCpuTime2 += Long.parseLong(cpuArr2[i]);
    }
    idleCpuTime2 = Long.parseLong(cpuArr2[4]);
} catch (IOException e) {
    e.printStackTrace();
} finally {
    if (cpuReader2 != null) {
        try {
            cpuReader2.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
double cpuUsage = ((double) (totalCpuTime2 - totalCpuTime1) - (double) (idleCpuTime2 - idleCpuTime1)) / (double) (totalCpuTime2 - totalCpuTime1) * 100.0;

这样就可以得到当前进程的CPU使用率了。