Android 打开照相机、获取相册图片、获取图片并裁减

一.调用照相机

　　注:surfaceView在当Activity不在前台的时候,会被销毁(onPause方法之后,执行销毁方法)当Activity回到前台时,在Activity执行onResume方法之后,会被重新创建,虽然如此,但并不需要在onResume方法中获取创建事件,因为surfaceView的生命周期可以通过其自身回调函数获取;

public class MainActivity extends Activity {
    private Camera camera;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        SurfaceView sf = (SurfaceView) findViewById(R.id.sv);
        sf.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        sf.getHolder().setFixedSize(176, 176);
        sf.getHolder().setKeepScreenOn(true);
        sf.getHolder().addCallback(new Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                camera = Camera.open();
                Camera.Parameters params = camera.getParameters();
                Log.e("camera", params.flatten()); // 获取可以设置的参数
                // params.setPreviewSize(480, 800);
                params.setPreviewFrameRate(5); // 每秒帧数
                params.setPictureSize(1024, 768); // 图片大小
                params.setJpegQuality(80); // 图片质量
                camera.setParameters(params);
                try {
                    camera.setPreviewDisplay(holder);
                    camera.startPreview();
                } catch (IOException e) {
                }
            }
            @Override
            public void surfaceChanged(SurfaceHolder holder, int format,
                    int width, int height) {
            }
            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {
                if (camera != null) {
                    camera.release(); // 不用之后要释放该对象
                }
            }
        });
    }

　　 public void takePicture(View v) {
        if (camera != null) {
            switch (v.getId()) {
            case R.id.take_picture:
                camera.takePicture(null, null, new LSPictureCallback());
                break;
            case R.id.auto_focus:
                camera.autoFocus(new AutoFocusCallback() {
                    @Override
                    public void onAutoFocus(boolean success, Camera camera) {
                    }
                });
                break;
            }
        }
    }

    private class LSPictureCallback implements PictureCallback {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            File jpgFile = new File(Environment.getExternalStorageDirectory(),
                    System.currentTimeMillis() + "");
            FileOutputStream outStream = null;
            try {
                outStream = new FileOutputStream(jpgFile);
                outStream.write(data);
                outStream.close();
                camera.startPreview(); // 照相保存图片之后继续进行画面预览
            } catch (Exception e) {
            }
        }
    }
}

二.获取系统默认的相册中的图片的方法
　　1、打开相册

                Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(i, 0x3001);

　　2、获取选择结果，重写onActivityResult方法

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 0x3001 && resultCode == RESULT_OK && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };

            Cursor cursor = getContentResolver().query(selectedImage,
                    filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();
            iv.setImageBitmap(BitmapFactory.decodeFile(picturePath));
        }
    }

三、 获取图片并截取

                File tempFile = new File(Environment.getExternalStorageDirectory().getPath() + "/cpm.jpg");
                Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                intent.setType("image/*");
                intent.putExtra("crop", "true");// 截取图片
                intent.putExtra("aspectX", 1);//
                intent.putExtra("aspectY", 1);// 表示x/y方向上的比例,在此设置为1:2
                intent.putExtra("output", Uri.fromFile(tempFile));
                intent.putExtra("outputFormat", "JPEG");
                startActivity(intent);