Android 拍照及相册选图的那些坑

原因：android手机厂商太多，ROM定制化太严重，给我们码农带了诸多不便。

Android的拍照功能的实现：

1.调用系统的相机：

步骤1：

 public void openCamera(View view) {        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);        mImagePath = FileUtil.genSystemCameraPhotoPath();        intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(mImagePath)));        startActivityForResult(intent, REQUST_CODE_CAMERA);  }  case R.id.button1://第一种方法，获取压缩图       Intent intent1 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);       // 启动相机       startActivityForResult(intent1, REQUEST_THUMBNAIL);       break;     case R.id.button2://第二种方法，获取原图       Intent intent2 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);       Uri uri = Uri.fromFile(new File(picPath));       //为拍摄的图片指定一个存储的路径       intent2.putExtra(MediaStore.EXTRA_OUTPUT, uri);       startActivityForResult(intent2, REQUEST_ORIGINAL);       break;

步骤2：

 @Override   protected void onActivityResult(int requestCode, int resultCode, Intent data) {     super.onActivityResult(requestCode, resultCode, data);     if (resultCode == RESULT_OK) {       if (requestCode == REQUEST_THUMBNAIL) {//对应第一种方法         /**          * 通过这种方法取出的拍摄会默认压缩，因为如果相机的像素比较高拍摄出来的图会比较高清，          * 如果图太大会造成内存溢出（OOM），因此此种方法会默认给图片压缩 ,坦白说拿到的就是一个缩略                                      图         */         Bundle bundle = data.getExtras();         Bitmap bitmap = (Bitmap) bundle.get("data");         mImageView.setImageBitmap(bitmap);       }       else if(resultCode == REQUEST_ORIGINAL){//对应第二种方法         /**          * 这种方法是通过内存卡的路径进行读取图片，所以的到的图片是拍摄的原图          */           result = BitmapFactory.decodeFile(picPath);        }      }     }   }

2.自定义的相机：

这个就简单提下
a.新建一个class extends SurfaceView
b.在其构造方法里面init一些基本的属性，增加回调 getHolder().addCallback(callback);

private SurfaceHolder.Callback callback = new SurfaceHolder.Callback() {        @Override        public void surfaceCreated(SurfaceHolder holder) {            try {                openCamera(mCameraFacing); // 1.打开相机                initParameters(); // 2.设置相机参数                mCamera.setPreviewDisplay(getHolder()); // 3.设置预览显示的Surface            } catch (Exception e) {                Toast.makeText(getContext(), "打开相机失败", Toast.LENGTH_SHORT).show();            }        }        @Override        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {            updateCamera(); // 4.更新相机属性，每次更换分辨率需要更新的操作，包括设置预览大小和方向，开始预览        }        @Override        public void surfaceDestroyed(SurfaceHolder holder) {            releaseCamera(); // 5.释放相机资源        }    };

c.差不多就a,b了，哈哈。。。

这里只说下可能出现的旋转问题（比如三星七八手机逆时针旋转了90度）：
既然照片存储的时候是歪的，那我们显示的时候就必须转正了，如何操作呢？

请看下步：

----------------->>>>>>> 旋转问题全家桶 <<<<<<<--------------------

法子1：旋转JPEG byte[]类型的图片(适合自定义相机拍出来回调的照片，PictureCallback里面)

//  在 Android 4.1.1 的 Camera 源码中找到    // Returns the degrees in clockwise. Values are 0, 90, 180, or 270.    public static int getOrientation(byte[] jpeg) {        if (jpeg == null) {            return 0;        }        int offset = 0;        int length = 0;        // ISO/IEC 10918-1:1993(E)        while (offset + 3 < jpeg.length && (jpeg[offset++] & 0xFF) == 0xFF) {            int marker = jpeg[offset] & 0xFF;            // Check if the marker is a padding.            if (marker == 0xFF) {                continue;            }            offset++;            // Check if the marker is SOI or TEM.            if (marker == 0xD8 || marker == 0x01) {                continue;            }            // Check if the marker is EOI or SOS.            if (marker == 0xD9 || marker == 0xDA) {                break;            }            // Get the length and check if it is reasonable.            length = pack(jpeg, offset, 2, false);            if (length < 2 || offset + length > jpeg.length) {                return 0;            }            // Break if the marker is EXIF in APP1.            if (marker == 0xE1 && length >= 8 &&                    pack(jpeg, offset + 2, 4, false) == 0x45786966 &&                    pack(jpeg, offset + 6, 2, false) == 0) {                offset += 8;                length -= 8;                break;            }            // Skip other markers.            offset += length;            length = 0;        }        // JEITA CP-3451 Exif Version 2.2        if (length > 8) {            // Identify the byte order.            int tag = pack(jpeg, offset, 4, false);            if (tag != 0x49492A00 && tag != 0x4D4D002A) {                return 0;            }            boolean littleEndian = (tag == 0x49492A00);            // Get the offset and check if it is reasonable.            int count = pack(jpeg, offset + 4, 4, littleEndian) + 2;            if (count < 10 || count > length) {                return 0;            }            offset += count;            length -= count;            // Get the count and go through all the elements.            count = pack(jpeg, offset - 2, 2, littleEndian);            while (count-- > 0 && length >= 12) {                // Get the tag and check if it is orientation.                tag = pack(jpeg, offset, 2, littleEndian);                if (tag == 0x0112) {                    // We do not really care about type and count, do we?                    int orientation = pack(jpeg, offset + 8, 2, littleEndian);                    switch (orientation) {                        case 1:                            return 0;                        case 3:                            return 180;                        case 6:                            return 90;                        case 8:                            return 270;                    }                    return 0;                }                offset += 12;                length -= 12;            }        }        return 0;    }

法子2：旋转从指定Path拿出来的图片

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;            case ExifInterface.ORIENTATION_FLIP_HORIZONTAL:                degree = 0;                break;            case ExifInterface.ORIENTATION_FLIP_VERTICAL:                degree = 180;                break;            case ExifInterface.ORIENTATION_TRANSPOSE:                degree = 90;                break;            case ExifInterface.ORIENTATION_TRANSVERSE:                degree = 270;                break;            }        } catch (IOException e) {            e.printStackTrace();        }        return degree;    }

法子3：旋转原始预览数据NV21（相机预览回调函数PreviewCallback）

private byte[] rotateYUV420Degree90(byte[] data, int imageWidth, int imageHeight)    {        byte [] yuv = new byte[imageWidth*imageHeight*3/2];        // Rotate the Y luma        int i = 0;        for(int x = 0;x < imageWidth;x++)        {            for(int y = imageHeight-1;y >= 0;y--)            {                yuv[i] = data[y*imageWidth+x];                i++;            }        }        // Rotate the U and V color components        i = imageWidth*imageHeight*3/2-1;        for(int x = imageWidth-1;x > 0;x=x-2)        {            for(int y = 0;y < imageHeight/2;y++)            {                yuv[i] = data[(imageWidth*imageHeight)+(y*imageWidth)+x];                i--;                yuv[i] = data[(imageWidth*imageHeight)+(y*imageWidth)+(x-1)];                i--;            }        }        return yuv;    }

法子4：旋转的就是一个bitmap

@Override  public void onPictureTaken(byte[] data, Camera camera) {     Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);     Matrix matrix = new Matrix();     matrix.preRotate(rotate);     bitmap = Bitmap.createBitmap(bitmap ,0,0, bitmap .getWidth(), bitmap.getHeight(),matrix,true);  };

旋转完后可能还会有个镜像的问题(比如前置的摄像头)

Matrix matrix = new Matrix();matrix.postScale(-1, 1);bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

拍照的坑就赞告一段落了。休息一会儿吧，骚年。生命诚可贵！！！

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Android的图库选图的坑：

续