[Android SQLite]数据存储与访问 - 外部存储

接下来就到SD卡了吧 ^_^

不是所有的手机都有SD卡,但是Android系统本身提供了对SD卡很便捷的访问方法

一般下载的数据都比较大就都放到SD卡了...具体原因,未知 哈哈

public class SD_Demo extends Activity implements OnClickListener
{
private StringBuilder randomNumBersString = null;

private TextView displayView = null;

@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main1);
setupViews();
}

private void setupViews()
{
displayView = (TextView) findViewById(R.id.display);
findViewById(R.id.random).setOnClickListener(this);
findViewById(R.id.write).setOnClickListener(this);
randomNumBersString = new StringBuilder();
}

@Override
public void onClick(View v)
{
switch (v.getId())
{
case R.id.random:
for (int i = 0; i < 10; i++)
{
randomNumBersString.append(Math.random()+"\n");
}
displayView.setText(randomNumBersString.toString());
break;

case R.id.write:
String fileName = "SdcardFile-"+System.currentTimeMillis()+".txt";;
boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED); 
File dir = null;
if (sdCardExist)
{
dir = new File( Environment.getExternalStorageDirectory().toString() + File.separator + "123321");
if (!dir.exists())
{
dir.mkdirs();
}
}
if (dir.exists() && dir.canWrite())
{
File newFile = new File(dir.getAbsolutePath()+ "/" + fileName);
FileOutputStream fos = null;
try
{
newFile.createNewFile();
if (newFile.exists() && newFile.canWrite())
{
fos = new FileOutputStream(newFile);
fos.write(randomNumBersString.toString().getBytes());
displayView.setText(String.format("%s文件写入SD卡", fileName));
}
} catch (IOException e)
{
e.printStackTrace();
}finally
{
if (fos != null)
{
try
{
fos.flush();
fos.close();
} catch (IOException e)
{
e.printStackTrace();
}
}
}
}
break;
}
}
}

很有价值的参考文章

http://hi.baidu.com/tdskee/blog/item/af76a0515469bb08367abe8a.html