如何查看Android设备上剩余多少MB或GB？我正在使用JAVA和android SDK 2.0.1。
是否有任何系统服务会暴露此类内容？
答案 0 :(得分：75)
Yaroslav的回答将给出SD卡的大小，而不是可用空间。 StatFs的getAvailableBlocks()将返回正常程序仍可访问的块数。这是我正在使用的功能：
public static float megabytesAvailable(File f) {
StatFs stat = new StatFs(f.getPath());
long bytesAvailable = (long)stat.getBlockSize() * (long)stat.getAvailableBlocks();
return bytesAvailable / (1024.f * 1024.f);
}
public static float megabytesAvailable(File f) {
StatFs stat = new StatFs(f.getPath());
long bytesAvailable = 0;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR2)
bytesAvailable = (long) stat.getBlockSizeLong() * (long) stat.getAvailableBlocksLong();
else
bytesAvailable = (long) stat.getBlockSize() * (long) stat.getAvailableBlocks();
return bytesAvailable / (1024.f * 1024.f);
}
答案 1 :(得分：53)
尝试this code：
StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
long bytesAvailable = (long)stat.getBlockSize() *(long)stat.getBlockCount();
long megAvailable = bytesAvailable / 1048576;
System.out.println("Megs :"+megAvailable);
getBlockCount() - 返回SD卡的大小;
getAvailableBlocks() - 返回正常程序仍可访问的块数（感谢Joe）
答案 2 :(得分：21)
我设计了一些随时可用的功能，以获得不同单位的可用空间。您只需将其中任何一个复制到项目中即可使用这些方法。
/**
* @return Number of bytes available on External storage
*/
public static long getAvailableSpaceInBytes() {
long availableSpace = -1L;
StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
availableSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
return availableSpace;
}
/**
* @return Number of kilo bytes available on External storage
*/
public static long getAvailableSpaceInKB(){
final long SIZE_KB = 1024L;
long availableSpace = -1L;
StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
availableSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
return availableSpace/SIZE_KB;
}
/**
* @return Number of Mega bytes available on External storage
*/
public static long getAvailableSpaceInMB(){
final long SIZE_KB = 1024L;
final long SIZE_MB = SIZE_KB * SIZE_KB;
long availableSpace = -1L;
StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
availableSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
return availableSpace/SIZE_MB;
}
/**
* @return Number of gega bytes available on External storage
*/
public static long getAvailableSpaceInGB(){
final long SIZE_KB = 1024L;
final long SIZE_GB = SIZE_KB * SIZE_KB * SIZE_KB;
long availableSpace = -1L;
StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
availableSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
return availableSpace/SIZE_GB;
}
答案 3 :(得分：5)
自API版本18以来引入了新方法。
我使用类似的东西进行大磁盘缓存大小估计（对于Picasso OkHttp下载缓存）。辅助方法就是这样：
private static final String BIG_CACHE_PATH = "my-cache-dir";
private static final float MAX_AVAILABLE_SPACE_USE_FRACTION = 0.9f;
private static final float MAX_TOTAL_SPACE_USE_FRACTION = 0.25f;
static File createDefaultCacheDirExample(Context context) {
File cache = new File(context.getApplicationContext().getCacheDir(), BIG_CACHE_PATH);
if (!cache.exists()) {
cache.mkdirs();
}
return cache;
}
/**
* Calculates minimum of available or total fraction of disk space
*
* @param dir
* @return space in bytes
*/
@SuppressLint("NewApi")
static long calculateAvailableCacheSize(File dir) {
long size = 0;
try {
StatFs statFs = new StatFs(dir.getAbsolutePath());
int sdkInt = Build.VERSION.SDK_INT;
long totalBytes;
long availableBytes;
if (sdkInt < Build.VERSION_CODES.JELLY_BEAN_MR2) {
int blockSize = statFs.getBlockSize();
availableBytes = ((long) statFs.getAvailableBlocks()) * blockSize;
totalBytes = ((long) statFs.getBlockCount()) * blockSize;
} else {
availableBytes = statFs.getAvailableBytes();
totalBytes = statFs.getTotalBytes();
}
// Target at least 90% of available or 25% of total space
size = (long) Math.min(availableBytes * MAX_AVAILABLE_SPACE_USE_FRACTION, totalBytes * MAX_TOTAL_SPACE_USE_FRACTION);
} catch (IllegalArgumentException ignored) {
// ignored
}
return size;
}
答案 4 :(得分：5)
基于this回答，添加了对Android版本的支持＆lt; 18
public static float megabytesAvailable(File file) {
StatFs stat = new StatFs(file.getPath());
long bytesAvailable;
if(Build.VERSION.SDK_INT >= 18){
bytesAvailable = getAvailableBytes(stat);
}
else{
//noinspection deprecation
bytesAvailable = stat.getBlockSize() * stat.getAvailableBlocks();
}
return bytesAvailable / (1024.f * 1024.f);
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
private static long getAvailableBytes(StatFs stat) {
return stat.getBlockSizeLong() * stat.getAvailableBlocksLong();
}
答案 5 :(得分：4)
另外，如果要检查内存上的可用空间，请使用：
File path = Environment.getDataDirectory();
StatFs stat = new StatFs(path.getPath());
...
答案 6 :(得分：2)
Google has information on this on the getting started page - 请参阅查询可用空间。他们说你可以通过getFreeSpace()检查可用空间，但是他们说这是不准确的，你应该期望比这更少的可用空间。他们说：
如果返回的数字比您要保存的数据大小多几MB，或者文件系统小于90％已满，那么继续操作可能是安全的。否则，您可能不应该写入存储。
另外，他们提出的建议是，通常更有用的不是检查可用空间而只是查看try catch错误：
在保存文件之前，无需检查可用空间量。您可以尝试立即编写文件，然后捕获IOException（如果发生）。如果您不确切知道需要多少空间，则可能需要执行此操作。例如，如果在通过将PNG图像转换为JPEG来保存之前更改文件的编码，则事先不会知道文件的大小。
我建议只有非常大的文件大小才能预先检查可用的存储空间，这样您就不会浪费时间下载或创建一个文件，如果文件显然太大而无法容纳。在任何一种情况下，您都应该始终使用try catch，所以我认为事先检查可用空间的唯一参数是资源和时间的不必要使用是多少。
答案 7 :(得分：0)
我希望这段代码可以帮助别人。经测试工作正常。感谢上述成员澄清它。
/**
* Get the free disk available space in boolean to download requested file
*
* @return boolean value according to size availability
*/
protected static boolean isMemorySizeAvailableAndroid(long download_bytes, boolean isExternalMemory) {
boolean isMemoryAvailable = false;
long freeSpace = 0;
// if isExternalMemory get true to calculate external SD card available size
if(isExternalMemory){
try {
StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
freeSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
if(freeSpace > download_bytes){
isMemoryAvailable = true;
}else{
isMemoryAvailable = false;
}
} catch (Exception e) {e.printStackTrace(); isMemoryAvailable = false;}
}else{
// find phone available size
try {
StatFs stat = new StatFs(Environment.getDataDirectory().getPath());
freeSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
if(freeSpace > download_bytes){
isMemoryAvailable = true;
}else{
isMemoryAvailable = false;
}
} catch (Exception e) {e.printStackTrace(); isMemoryAvailable = false;}
}
return isMemoryAvailable;
}
答案 8 :(得分：-2)
public String TotalExtMemory()
{
StatFs statFs = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());
int Total = (statFs.getBlockCount() * statFs.getBlockSize()) / 1048576;
String strI = Integer.toString(Total);
return strI;
}
public String FreeExtMemory()
{
StatFs statFs = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());
int Free = (statFs.getAvailableBlocks() * statFs.getBlockSize()) / 1048576;
String strI = Integer.toString(Free);
return strI;
}
public String BusyExtMemory()
{
StatFs statFs = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());
int Total = (statFs.getBlockCount() * statFs.getBlockSize()) / 1048576;
int Free = (statFs.getAvailableBlocks() * statFs.getBlockSize()) / 1048576;
int Busy = Total - Free;
String strI = Integer.toString(Busy);
return strI;
}