我有这个类捕获图像，然后将其保存在SQLite中，但从我的理解，它保存为blob，（我在互联网上发现这个代码并重用了一部分），我想实际保存路径然后检索它，因为它的质量下降了很多。
public class fotos extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor>{
static final int CAPTURE_PHOTO = 2;
private FloatingActionButton add;
private ProgressDialog progressBar;
private int progressBarStatus = 0;
private Handler progressBarHandler = new Handler();
DbHelper dbHelper;
boolean active = false;
Bitmap thumbnail;
///////////////////////////////////////////////
ImagesAdapter imagesAdapter;
RecyclerView mRecyclerView;
private static final int IMAGES_LOADER = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fotos);
add = findViewById(R.id.add);
mRecyclerView = findViewById(R.id.recyclerView);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
imagesAdapter = new ImagesAdapter(this);
mRecyclerView.setAdapter(imagesAdapter);
getLoaderManager().initLoader(IMAGES_LOADER, null, this);
if(ContextCompat.checkSelfPermission(fotos.this, android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(fotos.this, new String[]{android.Manifest.permission.CAMERA, android.Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}else{
active = true;
}
dbHelper = new DbHelper(this);
}
public void takePicture(View view) {
Intent it = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(it, CAPTURE_PHOTO);
}
public void setProgressBar(){
progressBar = new ProgressDialog(this);
progressBar.setCancelable(true);
progressBar.setMessage("Espera, por favor...");
progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressBar.setProgress(0);
progressBar.setMax(100);
progressBar.show();
progressBarStatus = 0;
new Thread(new Runnable() {
@Override
public void run() {
while(progressBarStatus < 100){
progressBarStatus += 30;
try{
Thread.sleep(1000);
} catch (InterruptedException e){
e.printStackTrace();
}
progressBarHandler.post(new Runnable() {
@Override
public void run() {
progressBar.setProgress(progressBarStatus);
}
});
}
if(progressBarStatus >= 100){
try{
Thread.sleep(2000);
} catch (InterruptedException e){
e.printStackTrace();
}
progressBar.dismiss();
}
}
}).start();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == CAPTURE_PHOTO && resultCode == RESULT_OK){
onCaptureImageResult(data);
}
}
private void onCaptureImageResult(Intent data) {
//thumbnail = (Bitmap) data.getExtras().get("data");
setProgressBar();
thumbnail = (Bitmap) data.getExtras().get("data");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
thumbnail.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] date = baos.toByteArray();
dbHelper.addToDb(date);
Toast.makeText(fotos.this, "Imagem salva com sucesso!", Toast.LENGTH_SHORT).show();
}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
String[] projetion = {
DbHelper.COLUMN_NAME,
};
return new CursorLoader(this,
ImagesProvider.CONTENT_URI,
projetion,
null,
null,
null);
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
imagesAdapter.swapCursor(data);
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
imagesAdapter.swapCursor(null);
}
}
Db的：
public class DbHelper extends SQLiteOpenHelper{
private static final String TAG = DbHelper.class.getSimpleName();
private static final String DATABASE_NAME = "image.db";
private static final int DATABAS_VERSION = 1;
Context context;
SQLiteDatabase db;
ContentResolver mContentResolver;
public final static String COLUMN_NAME = "imagename";
public final static String TABLE_NAME = "imagetable";
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABAS_VERSION);
mContentResolver = context.getContentResolver();
db = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
final String SQL_CREATE_IMAGE_TABLE = "CREATE TABLE " + TABLE_NAME + " (" +
_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_NAME + " BLOB NOT NULL " + " );";
db.execSQL(SQL_CREATE_IMAGE_TABLE);
Log.d(TAG, "Database criado com sucesso!");
}
public void addToDb(byte[] date) {
ContentValues cv = new ContentValues();
cv.put(COLUMN_NAME, date);
db.insert(TABLE_NAME, null, cv);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
}
在清单
中 <application>
...
<activity android:name=".activitys.info_sinistro.midia.fotos" >
<meta-data
android:name=".activitys.info_sinistro.midia.fotos"
android:value=".activitys.info_sinistro.midia.fotos"/>
</activity>
<provider
android:name=".activitys.info_sinistro.Provider.ImagesProvider"
android:authorities="insidetechnology.studio.ostdor.xiope"
android:exported="true"/>
...
</application>
在API 24中我知道你需要这个提供者，所以这是正确的吗？
答案 0 :(得分：1)
我在我的应用程序中使用相同的原理，我使用内置摄像头捕获图像并在数据库中保存它的路径。
基本上，一旦你点击相机按钮就会发出你已经知道的意图，但我会分享它的完整性：
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getActivity().getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
Log.e(TAG, "Error while creating the file");
}
// Continue only if the File was successfully created
if (photoFile != null) {
mFile = photoFile;
Uri photoURI = FileProvider.getUriForFile(getActivity(), "com.yourpackage.fileprovider", photoFile);
//Uri photoURI = Uri.fromFile(photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}
}
我认为为了使FileProvider能够正常工作，您需要将其包含在<application>标记内的清单文件中：
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="com.yourpackage.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths">
</meta-data>
</provider>
@xml/file_paths：
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path name="my_images" path="." />
</paths>
最后在您的dispatchTakePictureIntent()中，您还可以使用createImageFile()创建一个文件：
private File createImageFile() throws IOException {
File path = new File(Util.getFileDirectory(getActivity()), "FOLDER_NAME");
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(new Date());
String imageFileName = "FileName_" + timeStamp + ".jpg";
if(path.mkdirs()) {
Log.v(TAG, "Directory created");
} else {
Log.d(TAG, "Directory is already present");
}
return new File(path, imageFileName);
}
最后，您将获得onActivityResult()中的图片：
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_IMAGE_CAPTURE) {
if (resultCode == RESULT_OK) {
// you got the photo
String imagePath = mImage.getAbsolutePath()
// you can save this path to the database
} else if (resultCode != RESULT_CANCELED) {
Log.e(TAG, "Error while taking a photo. Error " + resultCode);
}
}
}
这会有效，但是FileProvider可能会有一些额外的不必要的步骤，如果我错了，请有人纠正我。但是这段代码正在运作。