需求描述：

在很多时候，我们需要在APP中调用摄像头拍摄相片或者选取本地相册中的图片进行裁剪，然后将裁剪后的图片上传至后台服务器。这方面有很多种实现方法，所以不再罗列，我只将我在这方面遇到的一些细节优化的地方总结一下。

关于裁剪

用的是https://github.com/jdamcd/android-crop， above API-14。这个开源代码将Itent封装的比较好。

工具入口是：

public class Crop {

public static final int REQUEST_CAPTURE = 1216;

public static final int REQUEST_CROP = 6709;

public static final int REQUEST_PICK = 9162;

public static final int RESULT_ERROR = 404;

static interface Extra {

String ASPECT_X = "aspect_x";

String ASPECT_Y = "aspect_y";

String MAX_X = "max_x";

String MAX_Y = "max_y";

String ERROR = "error";

}

private Intent cropIntent;

/**

* Create a crop Intent builder with source and destination image Uris

*

* @param source Uri for image to crop

* @param destination Uri for saving the cropped image

*/

public static Crop of(Uri source, Uri destination) {

return new Crop(source, destination);

}

private Crop(Uri source, Uri destination) {

cropIntent = new Intent();

cropIntent.setData(source);

cropIntent.putExtra(MediaStore.EXTRA_OUTPUT, destination);

}

/**

* Set fixed aspect ratio for crop area

* 自定义宽高比

* @param x Aspect X

* @param y Aspect Y

*/

public Crop withAspect(int x, int y) {

cropIntent.putExtra(Extra.ASPECT_X, x);

cropIntent.putExtra(Extra.ASPECT_Y, y);

return this;

}

/**

* Crop area with fixed 1:1 aspect ratio

* 默认一比一宽高比

*/

public Crop asSquare() {

cropIntent.putExtra(Extra.ASPECT_X, 1);

cropIntent.putExtra(Extra.ASPECT_Y, 1);

return this;

}

/**

* Set maximum crop size

*

* @param width Max width

* @param height Max height

*/

public Crop withMaxSize(int width, int height) {

cropIntent.putExtra(Extra.MAX_X, width);

cropIntent.putExtra(Extra.MAX_Y, height);

return this;

}

/**

* Send the crop Intent from an Activity

*

* @param activity Activity to receive result

*/

public void start(Activity activity) {

start(activity, REQUEST_CROP);

}

/**

* Send the crop Intent from an Activity with a custom requestCode

*

* @param activity Activity to receive result

* @param requestCode requestCode for result

*/

public void start(Activity activity, int requestCode) {

activity.startActivityForResult(getIntent(activity), requestCode);

}

/**

* Send the crop Intent from a Fragment

*

* @param context Context

* @param fragment Fragment to receive result

*/

public void start(Context context, Fragment fragment) {

start(context, fragment, REQUEST_CROP);

}

/**

* Send the crop Intent from a support library Fragment

*

* @param context Context

* @param fragment Fragment to receive result

*/

public void start(Context context, android.support.v4.app.Fragment fragment) {

start(context, fragment, REQUEST_CROP);

}

/**

* Send the crop Intent with a custom requestCode

*

* @param context Context

* @param fragment Fragment to receive result

* @param requestCode requestCode for result

*/

@TargetApi(Build.VERSION_CODES.HONEYCOMB)

public void start(Context context, Fragment fragment, int requestCode) {

fragment.startActivityForResult(getIntent(context), requestCode);

}

/**

* Send the crop Intent with a custom requestCode

*

* @param context Context

* @param fragment Fragment to receive result

* @param requestCode requestCode for result

*/

public void start(Context context, android.support.v4.app.Fragment fragment, int requestCode) {

fragment.startActivityForResult(getIntent(context), requestCode);

}

/**

* Get Intent to start crop Activity

*

* @param context Context

* @return Intent for CropImageActivity

*/

public Intent getIntent(Context context) {

cropIntent.setClass(context, CropImageActivity.class);

return cropIntent;

}

/**

* Retrieve URI for cropped image, as set in the Intent builder

*

* @param result Output Image URI

*/

public static Uri getOutput(Intent result) {

return result.getParcelableExtra(MediaStore.EXTRA_OUTPUT);

}

/**

* Retrieve error that caused crop to fail

*

* @param result Result Intent

* @return Throwable handled in CropImageActivity

*/

public static Throwable getError(Intent result) {

return (Throwable) result.getSerializableExtra(Extra.ERROR);

}

/**

* Utility to start an image picker

*

* @param activity Activity that will receive result

*/

public static void pickImage(Activity activity) {

pickImage(activity, REQUEST_PICK);

}

/**

* Utility to start an image picker with request code

*

* @param activity Activity that will receive result

* @param requestCode requestCode for result

*/

public static void pickImage(Activity activity, int requestCode) {

Intent intent = new Intent(Intent.ACTION_GET_CONTENT).setType("image/*");

try {

activity.startActivityForResult(intent, requestCode);

} catch (ActivityNotFoundException e) {

Toast.makeText(activity, R.string.crop__pick_error, Toast.LENGTH_SHORT).show();

}

}

/**

* 拍照获取

* @param activity

* 需要在Intent中加入保存的SD卡路径，否则onActivityResult中的得到的data图片会压缩很小

*/

public static void pickCAPTURE(Activity activity, Uri path) {

pickCAPTURE(activity, path, REQUEST_CAPTURE);

}

public static void pickCAPTURE(Activity activity, Uri path, int requestCode){

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

intent.putExtra(MediaStore.EXTRA_OUTPUT, path);

try {

activity.startActivityForResult(intent, requestCode);

} catch (ActivityNotFoundException e) {

Toast.makeText(activity, R.string.crop__pick_error, Toast.LENGTH_SHORT).show();

}

}

}

当然你也可以不用这个，用SDK本身的裁剪功能就可以了，同样可以在onActivityResult中返回得到裁剪的图片，而且可以自定义裁剪尺寸：

private void startImageZoom(Uri uri) {

Intent intent = new Intent("com.android.camera.action.CROP");

intent.setDataAndType(uri, "image/*");

intent.putExtra("crop", "true");

intent.putExtra("aspectX", 1);

intent.putExtra("aspectY", 0.7);

intent.putExtra("outputX", 1080);

intent.putExtra("outputY", 756);

intent.putExtra("return-data", true);

getActivity().startActivityForResult(intent, 3);

}

关于Uri、Bitmap、以及保存路径的转换

提供一个工具类：

public class UtilsImageProcess {

/**

* 将得到的一个Bitmap保存到SD卡上，得到一个URI地址

*/

public static Uri saveBitmap(Bitmap bm) {

//在SD卡上创建目录

File tmpDir = new File(Environment.getExternalStorageDirectory() + "/org.chenlijian.test");

if (!tmpDir.exists()) {

tmpDir.mkdir();

}

File img = new File(tmpDir.getAbsolutePath() + "test.png");

try {

FileOutputStream fos = new FileOutputStream(img);

bm.compress(Bitmap.CompressFormat.PNG, 85, fos);

fos.flush();

fos.close();

return Uri.fromFile(img);

} catch (FileNotFoundException e) {

e.printStackTrace();

return null;

} catch (IOException e) {

e.printStackTrace();

return null;

}

}

/**

* 将得到的一个Bitmap保存到SD卡上，得到一个绝对路径

*/

public static String getPath(Bitmap bm) {

//在SD卡上创建目录

File tmpDir = new File(Environment.getExternalStorageDirectory() + "/org.chenlijian.test");

if (!tmpDir.exists()) {

tmpDir.mkdir();

}

File img = new File(tmpDir.getAbsolutePath() + "/test.png");

try {

FileOutputStream fos = new FileOutputStream(img);

bm.compress(Bitmap.CompressFormat.PNG, 85, fos);

fos.flush();

fos.close();

return img.getCanonicalPath();

} catch (FileNotFoundException e) {

e.printStackTrace();

return null;

} catch (IOException e) {

e.printStackTrace();

return null;

}

}

/**

* 将图库中选取的图片的URI转化为URI

*/

public static Uri convertUri(Uri uri, Context context) {

InputStream is;

try {

is = context.getContentResolver().openInputStream(uri);

Bitmap bitmap = BitmapFactory.decodeStream(is);

is.close();

return saveBitmap(bitmap);

} catch (FileNotFoundException e) {

e.printStackTrace();

return null;

} catch (IOException e) {

e.printStackTrace();

return null;

}

}

/**

* 在拍摄照片之前生成一个文件路径Uri，保证拍出来的照片没有被压缩太小,用日期作为文件名，确保唯一性

*/

public static String getSavePath(){

String saveDir = Environment.getExternalStorageDirectory() + "/org.chenlijian.test";

File dir = new File(saveDir);

if (!dir.exists()) {

dir.mkdir();

}

Date date = new Date();

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");

String fileName = saveDir + "/" + formatter.format(date) + ".png";

return fileName;

}

/**

* 计算图片的缩放值

*/

public static int calculateInSampleSize(BitmapFactory.Options options,int reqWidth, int reqHeight) {

final int height = options.outHeight;

final int width = options.outWidth;

int inSampleSize = 1;

if (height > reqHeight || width > reqWidth) {

final int heightRatio = Math.round((float) height/ (float) reqHeight);

final int widthRatio = Math.round((float) width / (float) reqWidth);

inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;

}

return inSampleSize;

}

/**

* 根据路径获得图片并压缩，返回bitmap用于显示

*/

public static Bitmap getSmallBitmap(String filePath) {

final BitmapFactory.Options options = new BitmapFactory.Options();

options.inJustDecodeBounds = true;

BitmapFactory.decodeFile(filePath, options);

// Calculate inSampleSize

options.inSampleSize = calculateInSampleSize(options, 480, 800);

// Decode bitmap with inSampleSize set

options.inJustDecodeBounds = false;

// 设置为true，画质更好一点，加载时间略长

options.inPreferQualityOverSpeed = true;

return BitmapFactory.decodeFile(filePath, options);

}

}

关于拍照

通过拍照Intent，然后onActivityResult得到图片样张，再对其进行裁剪。一般得到的图片都很小，是因为经过了压缩，所以为了不让其压缩，需要在拍照Intent中加入保存的SD卡路径，然后在onActivityResult中得到的data为null，我们直接获取之前设置的SD卡路径的图片对其进行裁剪即可。当然不进行压缩图片肯定很大，之后我们可以根据自己的需求进行压缩。代码上面已经贴出来了。

示例

选择获取图片方式：

case R.id.btn_dialog_one_select_img:

imgDialog.dismiss();

path_name = UtilsImageProcess.getSavePath();

Crop.pickCAPTURE(getActivity(), Uri.fromFile(new File(path_name)));

break;

case R.id.btn_dialog_two_select_img:

imgDialog.dismiss();

Crop.pickImage(getActivity());

break;

返回处理结果：

public void onActivityResult(int requestCode, int resultCode, Intent data) {

// TODO Auto-generated method stub

super.onActivityResult(requestCode, resultCode, data);

if (resultCode == Activity.RESULT_OK) {

if (requestCode == Crop.REQUEST_CAPTURE) { //拍照得到URI

Bitmap bitmap = UtilsImageProcess.getSmallBitmap(path_name);

Uri source = UtilsImageProcess.saveBitmap(bitmap);

beginCrop(source);

} else if (requestCode == Crop.REQUEST_PICK && data != null) { //从相册中选取得到得到图片

Uri source = UtilsImageProcess.convertUri(data.getData(), getActivity());

beginCrop(source);

} else if (requestCode == Crop.REQUEST_CROP && data != null) { //得到裁剪后的图片

handleCrop(data);

}else {

((ActivityMain) getActivity()).dialogDismiss();

}

}

}

//启动裁剪Activity

private void beginCrop(Uri source) {

Uri destination1 = Uri.fromFile(new File(Environment.getExternalStorageDirectory() + "/org.chenlijian.test", "test_crop.png"));

Crop.of(source, destination1).asSquare().start(getActivity());

}

//处理裁剪得到的图片，通过Volley上传到服务器

private void handleCrop(Intent data) {

Uri uri = Crop.getOutput(data);

try {

Bitmap bitmap = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), uri);

String imagePath = UtilsImageProcess.getPath(bitmap);

uploadTask = networkModule.arrangeUploadImg("arrangeUploadImg", imagePath);

uploadTask.setId(0);

uploadTask.setReceiver(this);

uploadTask.pullTrigger();

} catch (IOException e) {

e.printStackTrace();

}

}

关于自定义封装Volley接口，上传图片或者文件，我会在下一篇文章中进行分析。