Question

我已经实现了从SD或相机中选择图像的代码。但是，我的图片并未显示在ImageView中，我无法从SD卡中选择图片。

当我点击SD卡中的图像时，它会立即跳回我的活动。

    final String[] items = new String[] {"From Camera","From SD Card"};
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.select_dialog_item,items);
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Select Image");
    builder.setAdapter(adapter,new DialogInterface.OnClickListener(){
        public void onClick(DialogInterface dialog,int which){
            if(which == 0){
                intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                File file = new File(Environment.getExternalStorageDirectory(),"event_image"+String.valueOf(System.currentTimeMillis()+".jpg"));
                imageCaptureUri = Uri.fromFile(file);
                try {
                    intent.putExtra(MediaStore.EXTRA_OUTPUT,imageCaptureUri);
                    intent.putExtra("return data",true);
                    startActivityForResult(intent,PICK_FROM_CAMERA);
                }catch(Exception ex){
                    ex.printStackTrace();
                }
                dialog.cancel();
            }else{
                intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent,"Complete action using"),PICK_FROM_FILE);
            }
        }
    });
    final AlertDialog dialog = builder.create();
    mImageView  = (ImageView) findViewById(R.id.imageView);
    imagePicker = (ImageButton) findViewById(R.id.image_picker);
    imagePicker.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v){
            dialog.show();
        }
    });

  @Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode != RESULT_OK)
        return;
    Bitmap bitmap = null;
    String path ="";
    if(requestCode == PICK_FROM_FILE) {
        imageCaptureUri = data.getData();
        path = getRealPathFromURI(imageCaptureUri);
        if(path == null)
            path = imageCaptureUri.getPath();
        if(path != null){
            bitmap = BitmapFactory.decodeFile(path);
        }
    }else{
        path = imageCaptureUri.getPath();
        bitmap = BitmapFactory.decodeFile(path);
    }
    mImageView.setImageBitmap(bitmap);
}


  public String getRealPathFromURI(Uri contentURI){
    String[] proj = {MediaStore.Images.Media.DATA};
    Cursor cursor = managedQuery(contentURI,proj,null,null,null);
    if(cursor == null) return null;
    int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    cursor.moveToFirst();
    return cursor.getString(column_index);
}

Answer 1

首先，你需要在AndroidManifest.xml中使用权限 WRITE_EXTERNAL_STORAGE

在xml布局中：

<ImageView
    android:id="@+id/img"
    android:layout_width="match_parent"
    android:layout_height="380dp"
    android:background="#f241c9" />

<Button
    android:id="@+id/btnCapture"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="20dp"
    android:text="Take Photo" />

<Button
    android:id="@+id/btnPick"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="20dp"
    android:text="Pick Photo" />

在您的活动课程中：

private static final String TAG = "my_log";
private static final int REQUEST_CAPTURE_FROM_CAMERA = 1;
private static final int REQUEST_PICK_FROM_FILE = 2;
private static final int REQUEST_CROP_INTENT = 3;

ImageView img;
Button btnCapture, btnPick;
File file;

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

    img = (ImageView) findViewById(R.id.img);
    btnCapture = (Button) findViewById(R.id.btnCapture);
    btnPick = (Button) findViewById(R.id.btnPick);

    btnCapture.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
            file = new File(Environment.getExternalStorageDirectory() + File.separator + "img_captured.jpg");
            // put Uri as extra in intent object
            intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
            startActivityForResult(intent, REQUEST_CAPTURE_FROM_CAMERA);
        }
    });

    btnPick.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent, "Complete action using"), REQUEST_PICK_FROM_FILE);
        }
    });

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (resultCode != RESULT_OK) return;

    if (requestCode == REQUEST_CAPTURE_FROM_CAMERA) {
        try {
            cropImage(Uri.fromFile(file));
        } catch (ActivityNotFoundException e) {
            Toast.makeText(this, "Your device does not support the crop action!", Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }
    } else if (requestCode == REQUEST_PICK_FROM_FILE) {
        try {
            cropImage(data.getData());
        } catch (ActivityNotFoundException e) {
            Toast.makeText(this, "Your device does not support the crop action!", Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }
    } else if (requestCode == REQUEST_CROP_INTENT) {
        // Create an instance of bundle and get the returned data
        Bundle extras = data.getExtras();
        // get the cropped bitmap from extras
        Bitmap bitmap = extras.getParcelable("data");
        img.setImageBitmap(bitmap);
        if (saveBitmapToStorage(bitmap)) {
            Log.d(TAG, "Bitmap saved to file successful.");
        } else {
            Log.d(TAG, "Failed to save Bitmap to storage.");
        }
    }

}

public void cropImage(Uri picUri) {
    //call the standard crop action intent
    Intent cropIntent = new Intent("com.android.camera.action.CROP");
    //indicate image type and Uri of image
    cropIntent.setDataAndType(picUri, "image/*");
    //set crop properties
    cropIntent.putExtra("crop", "true");
    //indicate aspect of desired crop
    cropIntent.putExtra("aspectX", 1);
    cropIntent.putExtra("aspectY", 1);
    //indicate output X and Y
    cropIntent.putExtra("outputX", 256);
    cropIntent.putExtra("outputY", 256);
    //retrieve data on return
    cropIntent.putExtra("return-data", true);
    //start the activity - we handle returning in onActivityResult
    startActivityForResult(cropIntent, REQUEST_CROP_INTENT);
}

private boolean saveBitmapToStorage(Bitmap finalBitmap) {
    boolean result = false;

    File file = new File(Environment.getExternalStorageDirectory() + File.separator + "img_cropped.jpg");
    Log.d(TAG, "file path = " + file.getAbsolutePath());

    try {
        FileOutputStream out = new FileOutputStream(file);
        finalBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
        out.flush();
        out.close();

        // send Broadcast to notify this photo and see it in Gallery
        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
        Uri contentUri = Uri.fromFile(file);
        mediaScanIntent.setData(contentUri);
        sendBroadcast(mediaScanIntent);

        result = true;
    } catch (Exception e) {
        e.printStackTrace();
    }

    return result;
}

Android选择图像或相机

1 个答案: