1. 旋转角度

当我们从手机读取图片时候发现其图片旋转了90或者其他度数,比如三星拍照后的照片就是个例子.这时候我们读取出来判断角度然后在逆向回转为正向的图片

1. 所需类 ExifInterface
   Exif是 Exchangeable Image File 缩写

/*** 读取图片属性：旋转的角度* * @param path 图片绝对路径* @return degree 旋转角度*/public static int readPictureDegree(String path) {int degree = 0;try {ExifInterface exifInterface = new ExifInterface(path);int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION,ExifInterface.ORIENTATION_NORMAL);switch (orientation) {case ExifInterface.ORIENTATION_ROTATE_90:degree = 90;break;case ExifInterface.ORIENTATION_ROTATE_180:degree = 180;break;case ExifInterface.ORIENTATION_ROTATE_270:degree = 270;break;}} catch (IOException e) {e.printStackTrace();}return degree;}

/*** 旋转图片* * @param angle 旋转角度* @param bitmap 原图* @return bitmap 旋转后的图片*/public static Bitmap rotateImage(int angle, Bitmap bitmap) {// 图片旋转矩阵Matrix matrix = new Matrix();matrix.postRotate(angle);// 得到旋转后的图片Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0,bitmap.getWidth(), bitmap.getHeight(), matrix, true);return resizedBitmap;}

2. 调用系统的剪切图片软件

当我们某个图片过大 想让用户自行选择剪切区域

1. 意图Intent的action “com.android.camera.action.CROP”
2. 意图Intent的data类型 文件地址Uri 如Uri.fromFile(new File(fileSrc))
3. 意图intent的type类型(mime) “image/*”

以下是可以传入到intent的数值 (putExtra)

/**** 裁剪图片* @param activity Activity* @param uri 图片的Uri*/public static void cropPicture(Activity activity, Uri uri) {Intent innerIntent = new Intent("com.android.camera.action.CROP");innerIntent.setDataAndType(uri, "image/*");innerIntent.putExtra("crop", "true");// 设置true才能出剪辑的小方框，不然没有剪辑功能，只能选取图片innerIntent.putExtra("aspectX", 1); // 放大缩小比例的XinnerIntent.putExtra("aspectY", 1);// 放大缩小比例的X   这里的比例为：   1:1innerIntent.putExtra("outputX", 320);  //这个是限制输出图片大小innerIntent.putExtra("outputY", 320); innerIntent.putExtra("return-data", true);// 切图大小不足输出，无黑框innerIntent.putExtra("scale", true);innerIntent.putExtra("scaleUpIfNeeded", true);File imageFile = new File(getImagePath(activity.getApplicationContext()));innerIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(imageFile));innerIntent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());activity.startActivityForResult(innerIntent, REQUEST_CROP_IMAGE);}

//回调:activityforresult
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data){
// 获取返回数据
Bitmap bmp = data.getParcelableExtra("data");}

3. 拍照获取图片

1. intent 的action: MediaStore.ACTION_IMAGE_CAPTURE
   直接案例:

// 设置相机拍照后照片保存路径File mPictureFile = new File(Environment.getExternalStorageDirectory(), "picture" + System.currentTimeMillis()/1000 + ".jpg");// 启动拍照,并保存到临时文件Intent mIntent = new Intent();mIntent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);mIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(mPictureFile));mIntent.putExtra(MediaStore.Images.Media.ORIENTATION, 0);startActivityForResult(mIntent, REQUEST_CAMERA_IMAGE);

回调acativityforesult

protected void onActivityResult(int requestCode, int resultCode, Intent data) {if (resultCode != RESULT_OK) {return;}if (!mPictureFile.exists()) {showTip("拍照失败，请重试");return;}fileSrc = mPictureFile.getAbsolutePath();}

4.更新画册

当你更新一张图片在手机中时不会立即出现在图册中,需要重启手机或者通知系统去扫描

private void updateGallery(String filename) {MediaScannerConnection.scanFile(this, new String[] {filename}, null,new MediaScannerConnection.OnScanCompletedListener() {@Overridepublic void onScanCompleted(String path, Uri uri) {}});}

5.从手机相册获取

直接案例

Intent intent = new Intent();intent.setType("image/*");intent.setAction(Intent.ACTION_PICK);startActivityForResult(intent, REQUEST_PICTURE_CHOOSE);

回调:

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {if (resultCode != RESULT_OK) {return;}
if ("file".equals(data.getData().getScheme())) {// 有些低版本机型返回的Uri模式为filefileSrc = data.getData().getPath();} else {// Uri模型为content//选择数据地址字段String[] proj = {MediaStore.Images.Media.DATA};Cursor cursor = getContentResolver().query(data.getData(), proj,null, null, null);cursor.moveToFirst();//获取字段在第几列int idx = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);//获取所在地址fileSrc = cursor.getString(idx);cursor.close();}}