[英]Android Lollipop save image downloaded in background on SD-CARD
在之前我曾用过ANDROID套件的情况下,我能够毫无问题地将图像存储在sd卡上,但是现在,我遇到了很多困难。
我不明白如何使用新的Android Lollipop的Access Store框架,也不知道它对我的情况是否有用。
下面的代码是我的项目的一部分,并且运行良好
private Bitmap getBitmap(String url, String image){
String root = Environment.getExternalStorageDirectory().toString();
root = "/mnt/extSdCard/";
Bitmap bitmap = null;
File f=fileCache.getFile(url);
//from SD cache
bitmap = decodeFile(f);
if(bitmap!=null)
return bitmap;
try{
bitmap = BitmapFactory.decodeFile(root + image);
if(bitmap!=null){
return bitmap;
}
}catch (Exception e) {
e.printStackTrace();
}
//from web
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
Foto foto = new Foto();
try {
try{
foto = new ObjectMapper().readValue(new URL("http://www.xxxxxx.yyyy/project/script.php?id="+url),
Foto.class);
if(foto!=null){
String[] values = image.split("/");
File dir = new File(root + values[0]);
if (!dir.exists()) {
dir.mkdir();
String fname = values[1];
File file = new File (dir, fname);
bitmap = BitmapFactory.decodeByteArray(foto.getFoto(), 0, foto.getFoto().length);
try {
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}else{
String fname = values[1];
File file = new File (dir, fname);
bitmap = BitmapFactory.decodeByteArray(foto.getFoto(), 0, foto.getFoto().length);
try {
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
//bitmap = decodeFile(f);
return bitmap;
}else{
return bitmap;
}
}catch(Exception e){
e.printStackTrace();
return null;
}
} catch (Exception ex){
if (ex instanceof SQLiteConstraintException){
bitmap = BitmapFactory.decodeByteArray(foto.getFoto(), 0, foto.getFoto().length);
return bitmap;
}else{
ex.printStackTrace();
return null;
}
}
}else{
return bitmap;
}
}
我如何将其更改为使用Android的新ASF?
如果我使用Environment.getExternalStorageDirectory().getAbsolutePath();
我无法获取SD卡的路径。
谢谢
在这个例子中使用SAF,我能够在sdcard上写:
public class MainActivity extends AppCompatActivity {
Uri sdCardUri;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
startActivityForResult(intent, 1);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode)
{
case 1:
if (resultCode == Activity.RESULT_OK) {
sdCardUri = data.getData();
getContentResolver().takePersistableUriPermission(sdCardUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
}
createFile();
break;
}
}
private void createFile() {
DocumentFile sdCard=DocumentFile.fromTreeUri(this,sdCardUri);
DocumentFile createFile=sdCard.findFile("teste.txt");
if (createFile==null)
createFile=sdCard.createFile("text","teste.txt");
OutputStream outStream = null;
try {
outStream = getContentResolver().openOutputStream(createFile.getUri());
} catch (FileNotFoundException e) {
e.printStackTrace();
}
try {
String teste="Isto é um teste";
outStream.write(teste.getBytes());
outStream.flush();
outStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
我使用de SAF选择sdcard以获取完全权限,如https://metactrl.com/docs/sdcard-on-lollipop/中所述
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