如何获取设备的总 RAM 大小？

Question

我想获取设备的完整 RAM 大小。 memoryInfo.getTotalPss() 返回 0。ActivityManager.MemoryInfo 中没有获取 RAM 总大小的功能。

如何做到这一点？

Answer 1

从 API 级别 16 开始，您现在可以使用 MemoryInfo 类的 totalMem 属性。

像这样：

ActivityManager actManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
ActivityManager.MemoryInfo memInfo = new ActivityManager.MemoryInfo();
actManager.getMemoryInfo(memInfo);
long totalMemory = memInfo.totalMem;

API 15 级及以下仍需要使用 unix 命令，如cweiske's answer 所示。

Answer 2

标准 unix 命令：$ cat /proc/meminfo

注意/proc/meminfo 是一个文件。您实际上不必运行cat，您只需读取文件即可。

Answer 3

我可以通过这种方式获得可用的RAM内存

public String getTotalRAM() {

    RandomAccessFile reader = null;
    String load = null;
    DecimalFormat twoDecimalForm = new DecimalFormat("#.##");
    double totRam = 0;
    String lastValue = "";
    try {
        reader = new RandomAccessFile("/proc/meminfo", "r");
        load = reader.readLine();

        // Get the Number value from the string
        Pattern p = Pattern.compile("(\\d+)");
        Matcher m = p.matcher(load);
        String value = "";
        while (m.find()) {
            value = m.group(1);
            // System.out.println("Ram : " + value);
        }
        reader.close();

        totRam = Double.parseDouble(value);
        // totRam = totRam / 1024;

        double mb = totRam / 1024.0;
        double gb = totRam / 1048576.0;
        double tb = totRam / 1073741824.0;

        if (tb > 1) {
            lastValue = twoDecimalForm.format(tb).concat(" TB");
        } else if (gb > 1) {
            lastValue = twoDecimalForm.format(gb).concat(" GB");
        } else if (mb > 1) {
            lastValue = twoDecimalForm.format(mb).concat(" MB");
        } else {
            lastValue = twoDecimalForm.format(totRam).concat(" KB");
        }



    } catch (IOException ex) {
        ex.printStackTrace();
    } finally {
        // Streams.close(reader);
    }

    return lastValue;
}

测试到 Android 4.3：SAMSUNG S3

Answer 4

您可以使用以下代码获取总 RAM 大小：

var activityManager = GetSystemService(Activity.ActivityService) as ActivityManager;
var memoryInfo = new ActivityManager.MemoryInfo();
activityManager.GetMemoryInfo(memoryInfo);

var totalRam = memoryInfo.TotalMem / (1024 * 1024);

如果设备有 1GB RAM，totalRam 将为 1000。

Answer 5

要获取 RAM 值，只需执行以下操作：

ActivityManager actManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    ActivityManager.MemoryInfo memInfo = new ActivityManager.MemoryInfo();
    assert actManager != null;
    actManager.getMemoryInfo(memInfo);
    long totalMemory = memInfo.totalMem;
    long availMemory = memInfo.availMem;
    long usedMemory = totalMemory - availMemory;
    float precentlong = (((float) (availMemory / totalMemory)) * 100);

在这里，您将获得 Total 以及 Free 和 Used RAM 大小。 这些值将是“long”，因此将其格式化为人类可读的（即 MB/GB）。 使用以下方法：

 private String floatForm(double d) {
    return String.format(java.util.Locale.US, "%.2f", d);
}

private String bytesToHuman(long size) {
    long Kb = 1024;
    long Mb = Kb * 1024;
    long Gb = Mb * 1024;
    long Tb = Gb * 1024;
    long Pb = Tb * 1024;
    long Eb = Pb * 1024;

    if (size < Kb) return floatForm(size) + " byte";
    if (size >= Kb && size < Mb) return floatForm((double) size / Kb) + " KB";
    if (size >= Mb && size < Gb) return floatForm((double) size / Mb) + " MB";
    if (size >= Gb && size < Tb) return floatForm((double) size / Gb) + " GB";
    if (size >= Tb && size < Pb) return floatForm((double) size / Tb) + " TB";
    if (size >= Pb && size < Eb) return floatForm((double) size / Pb) + " Pb";
    if (size >= Eb) return floatForm((double) size / Eb) + " Eb";

    return "0";
}

所以现在将这些值设置为任何文本视图：

totalRam_tv.setText("".concat(bytesToHuman(totalMemory)));

Answer 6

获取总内存和可用内存的简单方法如下：

//Method call returns the free RAM currently and returned value is in bytes.
Runtime.getRuntime().freeMemory();

//Method call returns the total RAM currently and returned value is in bytes.
Runtime.getRuntime().maxMemory();

希望这会奏效。

要将值格式化为 KB 和 MB，可以使用以下方法：

/**
     * Method to format the given long value in human readable value of memory.
     * i.e with suffix as KB and MB and comma separated digits.
     *
     * @param size Total size in long to be formatted. <b>Unit of input value is assumed as bytes.</b>
     * @return String the formatted value. e.g for input value 1024 it will return 1KB.
     * <p> For the values less than 1KB i.e. same input value will return back. e.g. for input 900 the return value will be 900.</p>
     */
    private String formatSize(long size) {
        String suffix = null;

        if (size >= 1024) {
            suffix = " KB";
            size /= 1024;
            if (size >= 1024) {
                suffix = " MB";
                size /= 1024;
            }
        }

        StringBuilder resultBuffer = new StringBuilder(Long.toString(size));

        int commaOffset = resultBuffer.length() - 3;
        while (commaOffset > 0) {
            resultBuffer.insert(commaOffset, ',');
            commaOffset -= 3;
        }

        if (suffix != null) resultBuffer.append(suffix);
        return resultBuffer.toString();
    }

可以自定义方法体以获得理想的结果。