android - 如何获取外部存储 SD 卡大小(已安装 SD 卡)？

Question

Link :I worked on based on this Link

我添加了这一行来查找尺寸(内部和外部)尺寸，

return availableExternalMemorySize/(1024*1024);

我在我的平板电脑上测试过。我得到内部和外部 SD 卡大小，

在内部存储中:

1. 总内存 --1007
2. 可用内存 --683

在外部存储中:

1. 总内存 -- 1763
2. 可用内存 -- 1554

但在平板电脑中，我看到了设置。外部存储大小为 8GB。但是当我以编程方式测试时，它显示了 1.7 GB。

查找外部存储大小的过程是什么？

Answer 1

要获取外部 SD 卡的可用“空闲”空间以显示与菜单->设置->SD 卡和手机存储的号码一致的号码，请使用以下代码:

StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
double sdAvailSize = (double)stat.getAvailableBlocks()
                   * (double)stat.getBlockSize();
//One binary gigabyte equals 1,073,741,824 bytes.
double gigaAvailable = sdAvailSize / 1073741824;

以下是获取内部存储大小的方法:

 StatFs statFs = new StatFs(Environment.getRootDirectory().getAbsolutePath());        
 long blockSize = statFs.getBlockSize();
 long totalSize = statFs.getBlockCount()*blockSize;
 long availableSize = statFs.getAvailableBlocks()*blockSize;
 long freeSize = statFs.getFreeBlocks()*blockSize;

以下是获取外部存储大小(SD 卡大小)的方法:

 StatFs statFs = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());        
 long blockSize = statFs.getBlockSize();
 long totalSize = statFs.getBlockCount()*blockSize;
 long availableSize = statFs.getAvailableBlocks()*blockSize;
 long freeSize = statFs.getFreeBlocks()*blockSize;

---

简短的笔记

空闲 block :

The total number of blocks that are free on the file system, including reserved blocks (that are not available to normal applications).

可用 block :

The number of blocks that are free on the file system and available to applications.

---

检测SD卡是否挂载的方法如下:

 String state = Environment.getExternalStorageState();
 if (Environment.MEDIA_MOUNTED.equals(state)) 
 {
   // We can read and write the media    
 } 
 else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) 
 {
    // We can only read the media     
 } 
 else 
 {
    // No external media
 }

相关文档:http://developer.android.com/reference/android/os/StatFs.html