RxPermissions+Matisse+Luban实现图片选择并压缩

前言：这次带来的是使用RxPermissions+知乎图片选择器Matisse+图片压缩工具Luban实现图片选择的功能。

implementation 'com.zhihu.android:matisse:0.5.1'
implementation 'com.github.tbruyelle:rxpermissions:0.10.2'
implementation 'top.zibin:Luban:1.1.7'

1.首先在RxPermissions申请完权限后开启知乎图片选择器（注意：使用知乎开源框架Matisse需注意的地方）

RxPermissions rxPermissions=new RxPermissions(this);
rxPermissions.requestEachCombined(Manifest.permission.CAMERA,
                                Manifest.permission.READ_EXTERNAL_STORAGE,
                                Manifest.permission.WRITE_EXTERNAL_STORAGE)
                        .subscribe(new Consumer<Permission>() {
                            @Override
                            public void accept(Permission permission) throws Exception {
                                if (permission.granted) {
                                    MyModule_PerfectInformationActivity.myModule_choiceImageEnum= MyModule_ChoiceImageEnum.PERFECTINFORMATION_PERSIONFRAGMENT_USERIMAGE;
                                    Matisse.from(this)
                                            .choose(MimeType.ofImage())
                                            .countable(true)
                                            .capture(true) //使用拍照功能
                                            .captureStrategy(new CaptureStrategy(true, "com.example.yuyi.common_module.fileprovider")) //是否拍照功能，并设置拍照后图片的保存路径
                                            .maxSelectable(1)
                                            .restrictOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT)
                                            .thumbnailScale(0.8f)
                                            .forResult(MatisseStateValue.REQUEST_CODE_CHOOSE);
                                } else if (permission.shouldShowRequestPermissionRationale) {
                                    ToastUtils.showShort("您已拒绝权限申请");
                                } else {
                                    ToastUtils.showShort("您已拒绝权限申请，请前往设置>应用管理>权限管理打开权限");
                                }
                            }
                        });

2.在onActivityResult方法中用Luban进行图片压缩处理

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == MatisseStateValue.REQUEST_CODE_CHOOSE && resultCode == RESULT_OK) {
            File fileByUri = FileUtil.getFileByUri(Matisse.obtainResult(data).get(0), this);
//            压缩文件
            Luban.with(this)
                    .load(fileByUri)
                    .ignoreBy(100)
                    .filter(new CompressionPredicate() {
                        @Override
                        public boolean apply(String path) {
                            return !(TextUtils.isEmpty(path) || path.toLowerCase().endsWith(".gif"));
                        }
                    })
                    .setCompressListener(new OnCompressListener() {
                        @Override
                        public void onStart() {
                            Log.e("测试", "开始");
                        }

                        @Override
                        public void onSuccess(File file) {
                            //转换成功后的文件

                        }

                        @Override
                        public void onError(Throwable e) {
                            Log.e("测试", "失败");
                        }
                    }).launch();
        }
    }

这里需要我使用了一个工具类将Uri转为File

public class FileUtil {
    public static File getFileByUri(Uri uri, Context context) {
        String path = null;
        if ("file".equals(uri.getScheme())) {
            path = uri.getEncodedPath();
            if (path != null) {
                path = Uri.decode(path);
                ContentResolver cr = context.getContentResolver();
                StringBuffer buff = new StringBuffer();
                buff.append("(").append(MediaStore.Images.ImageColumns.DATA).append("=").append("'" + path + "'").append(")");
                Cursor cur = cr.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[] { MediaStore.Images.ImageColumns._ID, MediaStore.Images.ImageColumns.DATA }, buff.toString(), null, null);
                int index = 0;
                int dataIdx = 0;
                for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {
                    index = cur.getColumnIndex(MediaStore.Images.ImageColumns._ID);
                    index = cur.getInt(index);
                    dataIdx = cur.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
                    path = cur.getString(dataIdx);
                }
                cur.close();
                if (index == 0) {
                } else {
                    Uri u = Uri.parse("content://media/external/images/media/" + index);
                    System.out.println("temp uri is :" + u);
                }
            }
            if (path != null) {
                return new File(path);
            }
        } else if ("content".equals(uri.getScheme())) {
            // 4.2.2以后
            String[] proj = { MediaStore.Images.Media.DATA };
            Cursor cursor = context.getContentResolver().query(uri, proj, null, null, null);
            if (cursor.moveToFirst()) {
                int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                path = cursor.getString(columnIndex);
            }
            cursor.close();

            return new File(path);
        } else {
            //Log.i(TAG, "Uri Scheme:" + uri.getScheme());
        }
        return null;
    }
}

扩展：结合我之前的文章（Android图文上传）可以实现图文上传

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