第二次冲刺（四）

今天我完成了照相机的功能。

关键代码为：

private void showPop() {
        View bottomView = View.inflate(getActivity(), R.layout.layout_bottom_dialog, null);
        TextView mAlbum = bottomView.findViewById(R.id.tv_album);
        TextView mCamera = bottomView.findViewById(R.id.tv_camera);
        TextView mCancel = bottomView.findViewById(R.id.tv_cancel);

        pop = new PopupWindow(bottomView, -1, -2);
        pop.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
        pop.setOutsideTouchable(true);
        pop.setFocusable(true);
        WindowManager.LayoutParams lp = getActivity().getWindow().getAttributes();
        lp.alpha = 0.5f;
        getActivity().getWindow().setAttributes(lp);
        pop.setOnDismissListener(new PopupWindow.OnDismissListener() {

            @Override
            public void onDismiss() {
                WindowManager.LayoutParams lp = getActivity().getWindow().getAttributes();
                lp.alpha = 1f;
                getActivity().getWindow().setAttributes(lp);
            }
        });
        pop.setAnimationStyle(R.style.main_menu_photo_anim);
        pop.showAtLocation(getActivity().getWindow().getDecorView(), Gravity.BOTTOM, 0, 0);

        View.OnClickListener clickListener = new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                switch (view.getId()) {
                    case R.id.tv_album:
                        //相册
                        if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
                            //相册中的照片都是存储在SD卡上的，需要申请运行时权限，WRITE_EXTERNAL_STORAGE是危险权限，表示同时授予程序对SD卡的读和写的能力
                            ActivityCompat.requestPermissions(getActivity(), new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
                        }else {
                            openAlbum();

                        }
                        break;
                    case R.id.tv_camera:
                        //拍照
                        File outputImage = new File(getActivity().getExternalCacheDir(),"output_image.jpg");
                        try{
                            if(outputImage.exists())
                                outputImage.delete();
                            outputImage.createNewFile();
                        }catch (IOException e){
                            e.printStackTrace();
                        }
                        if(Build.VERSION.SDK_INT >=24){
                            imageUri = FileProvider.getUriForFile(getActivity(),
                                    "com.example.cameraalbumtest.fileprovider",outputImage);
                        }else{
                            imageUri = Uri.fromFile(outputImage);
                        }

                        Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                        intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);
                        startActivityForResult(intent,TAKE_PHOTO);
                        break;
                    case R.id.tv_cancel:
                        //取消
                        closePopupWindow();
                        break;
                }
                closePopupWindow();
            }
        };
        mCamera.setOnClickListener(clickListener);
        mAlbum.setOnClickListener(clickListener);

        mCancel.setOnClickListener(clickListener);
    }

    public void closePopupWindow() {
        if (pop != null && pop.isShowing()) {
            pop.dismiss();
            pop = null;
        }
    }

    private void openAlbum(){
        Intent intent = new Intent("android.intent.action.GET_CONTENT");
        intent.setType("image/*");
        startActivityForResult(intent,CHOOSE_PHOTO);//打开相册
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case TAKE_PHOTO:
                if (resultCode == RESULT_OK) {
                    try {
                        Bitmap bitmap = BitmapFactory.decodeStream(getActivity().getContentResolver().openInputStream(imageUri));
                        Touxiang.setImageBitmap(bitmap);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
                break;

            case CHOOSE_PHOTO:
                if(resultCode == RESULT_OK) {
                    //因为sdk19以后返回的数据不同，所以要根据手机系统版本进行不同的操作
                    //判断手机系统版本
                    if(Build.VERSION.SDK_INT >= 19) {
                        handleImageOnKiKai(data);
                    }else {
                        handleImageBeforeKiKai(data);
                    }
                }
                break;
            default:
                break;
        }
    }
    //>=19的操作
    @TargetApi(19)
    private void handleImageOnKiKai(Intent data) {
        String imagePath = null;
        Uri uri = data.getData();
        if(DocumentsContract.isDocumentUri(getActivity(), uri)) {
            //如果是Document类型的Uri，则通过document id 处理
            String docId = DocumentsContract.getDocumentId(uri);
            if("com.android.providers.media.documents".equals(uri.getAuthority())) {
                String id = docId.split(":")[1];
                String selection = MediaStore.Images.Media._ID + "=" + id;
                imagePath = getImagePath(
                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);
            }else if("com.android.providers.downloads.documents".equals(uri.getAuthority())) {
                Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));
                imagePath = getImagePath(contentUri, null);
            }else if("content".equalsIgnoreCase(uri.getScheme())) {
                //不是document类型的Uri，普通方法处理
                imagePath = getImagePath(uri, null);
            }
            displayImage(imagePath);
        }
    }

    //<19的操作
    private void handleImageBeforeKiKai(Intent data) {
        Uri uri = data.getData();
        String imagePath = getImagePath(uri, null);
        displayImage(imagePath);
    }

    private String getImagePath(Uri uri, String selection) {
        String path = null;
        //通过Uri 和selection获取真正的图片路径
        Cursor cursor = getActivity().getContentResolver().query(
                uri, null, selection, null, null);
        if(cursor != null) {
            if(cursor.moveToFirst()) {
                path = cursor.getString(
                        cursor.getColumnIndex(MediaStore.Images.Media.DATA));
            }
            cursor.close();
        }
        return path;
    }

    private void displayImage(String path) {
        if(path != null) {
            Bitmap bitmap = BitmapFactory.decodeFile(path);
            Touxiang.setImageBitmap(bitmap);
        }else {
            Toast.makeText(getActivity(), "Load Failed", Toast.LENGTH_LONG).show();
        }
    }