android.app.ActivityManager#getMemoryInfo ( )源码实例Demo

public void run() {
    mTimerTask = new TimerTask() {

        @Override
        public void run() {

            MemoryInfo mi = new MemoryInfo();
            ActivityManager activityManager = (ActivityManager) mContext.getSystemService(Activity.ACTIVITY_SERVICE);
            activityManager.getMemoryInfo(mi);
            Runtime runtime = Runtime.getRuntime();
            String s = String.format("free:%s%% %sKB total:%sKB max:%sKB ", runtime.freeMemory() * 100f / runtime.totalMemory(), runtime.freeMemory(), runtime.totalMemory() / 1024,
                    runtime.maxMemory() / 1024);
            // s += String.format("native: free:%sKB total:%sKB max:%sKB", android.os.Debug.getNativeHeapFreeSize() / 1024, android.os.Debug.getNativeHeapAllocatedSize() / 1024,
            // android.os.Debug.getNativeHeapSize() / 1024);
            // s += String.format("| availMem:%sKB", mi.availMem / 1024);
            Log.d("memory", s);
        }
    };

    mTimer = new Timer();
    mTimer.schedule(mTimerTask, 1000, 1000);
}
 

public static long getAvailMemory(Context context){
  ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
  ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
  am.getMemoryInfo(mi);
  //mi.availMem; 当前系统的可用内存
  //return Formatter.formatFileSize(context, mi.availMem);// 将获取的内存大小规格化
  WXLogUtils.w("app AvailMemory ---->>>"+mi.availMem/(1024*1024));
  return mi.availMem/(1024*1024);
}
 

public static long getAvailMemory(Context context){
  ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
  ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
  am.getMemoryInfo(mi);
  //mi.availMem; 当前系统的可用内存
  //return Formatter.formatFileSize(context, mi.availMem);// 将获取的内存大小规格化
  WXLogUtils.w("app AvailMemory ---->>>"+mi.availMem/(1024*1024));
  return mi.availMem/(1024*1024);
}
 

private static void checkMemoryConstraints() {
    final ActivityManager actManager = (ActivityManager) xdrip.getAppContext().getSystemService(Context.ACTIVITY_SERVICE);
    final ActivityManager.MemoryInfo memInfo = new ActivityManager.MemoryInfo();
    actManager.getMemoryInfo(memInfo);
    final long totalMemory = memInfo.totalMem;
    // TODO react to total memory
}
 

/**
 * 获取设备的可用内存大小
 *
 * @param cxt 应用上下文对象context
 * @return 当前内存大小
 */
public static int getDeviceUsableMemory(Context cxt) {
    ActivityManager am = (ActivityManager) cxt
            .getSystemService(Context.ACTIVITY_SERVICE);
    MemoryInfo mi = new MemoryInfo();
    am.getMemoryInfo(mi);
    // 返回当前系统的可用内存
    return (int) (mi.availMem / (1024 * 1024));
}
 

/**
 * Get available memory info.
 */
@TargetApi(Build.VERSION_CODES.CUPCAKE)
public static String getAvailMemory(Context context) {// 获取android当前可用内存大小
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
    am.getMemoryInfo(mi);
    // mi.availMem; 当前系统的可用内存
    return Formatter.formatFileSize(context, mi.availMem);// 将获取的内存大小规格化
}
 

public static Long getTotalMemory(Context cx) {// 获取android全部内存大小
	if (cx == null) {
		return 0L;
	}

	ActivityManager am = (ActivityManager) cx.getSystemService(Context.ACTIVITY_SERVICE);
	MemoryInfo mi = new MemoryInfo();
	am.getMemoryInfo(mi);
	LogUtil.i(TAG, "Total memory: " + mi.totalMem);
	// mi.totalMem; 当前系统的全部内存

	return mi.totalMem / BYTES_PER_MEGA;// 将获取的内存大小规格化
}
 

/**
 * 获取系统当前可用内存大小
 *
 * @param context
 * @return
 */
@TargetApi(Build.VERSION_CODES.CUPCAKE)
public static String getAvailMemory(Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
    am.getMemoryInfo(mi);
    return Formatter.formatFileSize(context, mi.availMem);// 将获取的内存大小规格化
}
 

private boolean isLowMemory() {
    ActivityManager activityManager = (ActivityManager)context.getSystemService(ACTIVITY_SERVICE);
    if (activityManager != null) {
        ActivityManager.MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
        activityManager.getMemoryInfo(memoryInfo);
        return memoryInfo.lowMemory;
    } else {
        return true;
    }
}
 

/**
 * 获取设备的可用内存大小
 * 
 * @param cxt
 *            应用上下文对象context
 * @return 当前内存大小
 */
public static int getDeviceUsableMemory(Context cxt) {
    ActivityManager am = (ActivityManager) cxt
            .getSystemService(Context.ACTIVITY_SERVICE);
    MemoryInfo mi = new MemoryInfo();
    am.getMemoryInfo(mi);
    // 返回当前系统的可用内存
    return (int) (mi.availMem / (1024 * 1024));
}
 

public static String getRamInfo(Context context) {
    long totalSize;
    long availableSize;

    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
    activityManager.getMemoryInfo(memoryInfo);

    totalSize = memoryInfo.totalMem;
    availableSize = memoryInfo.availMem;

    return String.format("%s / %s", Formatter.formatFileSize(context, availableSize), Formatter.formatFileSize(context, totalSize));
}
 

private boolean isLowMemory() {
    ActivityManager activityManager = (ActivityManager)context.getSystemService(ACTIVITY_SERVICE);
    if (activityManager != null) {
        ActivityManager.MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
        activityManager.getMemoryInfo(memoryInfo);
        return memoryInfo.lowMemory;
    } else {
        return true;
    }
}
 

public static long getFreeMemory(Context context) {

        // 获取android当前可用内存大小
        long fm = 0;
        try {
            ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
            ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
            am.getMemoryInfo(mi);
            fm = mi.availMem/(1024*1024);
        } catch (Exception e) {

        }

        return fm;
    }
 

private boolean isLowMemory() {
    ActivityManager activityManager = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);
    if (activityManager != null) {
        ActivityManager.MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
        activityManager.getMemoryInfo(memoryInfo);
        return memoryInfo.lowMemory;
    } else {
        return true;
    }
}
 

/**
 * 获取当前可用内存，返回数据以字节为单位。
 *
 * @param context 可传入应用程序上下文。
 * @return 当前可用内存单位为B。
 */
public static long getAvailableMemory(Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
    am.getMemoryInfo(memoryInfo);
    return memoryInfo.availMem;
}
 

/**
 * 获取android当前可用内存大小
 *
 * @param context
 * @return
 */
private static String getAvailMemory(Context context) {

    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
    if (am != null) {
        am.getMemoryInfo(mi);
    }
    //mi.availMem; 当前系统的可用内存
    return Formatter.formatFileSize(context, mi.availMem);
}
 

public static long getmem_UNUSED(Context mContext) {
    long MEM_UNUSED;
    // 得到ActivityManager
    ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);	
    // 创建ActivityManager.MemoryInfo对象          
    ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
    am.getMemoryInfo(mi);
    // 取得剩余的内存空间        
    MEM_UNUSED = mi.availMem/1048576;
    return MEM_UNUSED;
}
 

/**
 * 同步获取系统的总ram大小
 *
 * @param activityManager
 * @return
 */
private static long getRamTotalMem(ActivityManager activityManager) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
        ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
        activityManager.getMemoryInfo(mi);
        return mi.totalMem / 1024;
    } else if (sTotalMem.get() > 0L) {//如果已经从文件获取过值，则不需要再次获取
        return sTotalMem.get();
    } else {
        final long tm = getRamTotalMemByFile();
        sTotalMem.set(tm);
        return tm;
    }
}
 

public static long getFreeMemory() {
    ActivityManager am = (ActivityManager) BlockCanaryInternals.getContext().provideContext().getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
    am.getMemoryInfo(mi);
    return mi.availMem / 1024;
}
 

public static long getMemUnused(Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService("activity");
    MemoryInfo memoryInfo = new MemoryInfo();
    am.getMemoryInfo(memoryInfo);
    return memoryInfo.availMem / 1024;
}