如何优雅的处理Android 的OnActivityResult,RequestPermissions

序言

我们知道Android里面启动一个Activity For Result时，回调会回到原来这个Activity的OnActivityResult中，如果此时，你正在写一个其他组件，而不能直接依赖这个Activity那是不是很尴尬？
还有当我们在写一个图片库组件时，发现要请求权限，权限请求完后在进行操作，可是权限请求的回调依然在Activity中的onRequestPermissionsResult，那我们怎么做呢？
今天介绍一个开源库 ActivityResultPermission ，一个用于帮助OnActivityResult，PermissionRequest 解耦合的库，不需要依赖Activity中的回调.

原理

解耦合Activity中的回调，有两种方式

一种是启动一个新的Activity来判断权限，获取ActivityForResult的结果. （可以参考RxAcitityResult,RxPermission的实现方式）
如下:

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.IntentSender;
import android.os.Bundle;

import io.reactivex.functions.Action;

public class HolderActivity extends Activity {
    private static Request request;
    private OnPreResult onPreResult;
    private OnResult onResult;
    private int resultCode;
    private int requestCode;
    private Intent data;
    private static int FAILED_REQUEST_CODE = -909;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (request == null) {
            finish();
            return;
        }

        onPreResult = request.onPreResult();
        onResult = request.onResult();

        if (savedInstanceState != null) return;

        if (request instanceof RequestIntentSender) {
            RequestIntentSender requestIntentSender = (RequestIntentSender) request;

            if (requestIntentSender.getOptions() == null) startIntentSender(requestIntentSender);
            else startIntentSenderWithOptions(requestIntentSender);
        } else {
            try {
                startActivityForResult(request.intent(), 0);
            } catch (ActivityNotFoundException e) {
                if (onResult != null) {
                    onResult.error(e);
                }
            }
        }
    }

    private void startIntentSender(RequestIntentSender requestIntentSender) {
        try {
            startIntentSenderForResult(requestIntentSender.getIntentSender(), 0,
                    requestIntentSender.getFillInIntent(), requestIntentSender.getFlagsMask(),
                    requestIntentSender.getFlagsValues(), requestIntentSender.getExtraFlags());
        } catch (IntentSender.SendIntentException exception) {
            exception.printStackTrace();
            onResult.response(FAILED_REQUEST_CODE, RESULT_CANCELED, null);
        }
    }

    private void startIntentSenderWithOptions(RequestIntentSender requestIntentSender) {
        try {
            startIntentSenderForResult(requestIntentSender.getIntentSender(), 0,
                    requestIntentSender.getFillInIntent(), requestIntentSender.getFlagsMask(),
                    requestIntentSender.getFlagsValues(), requestIntentSender.getExtraFlags(), requestIntentSender.getOptions());
        } catch (IntentSender.SendIntentException exception) {
            exception.printStackTrace();
            onResult.response(FAILED_REQUEST_CODE, RESULT_CANCELED, null);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        this.resultCode = resultCode;
        this.requestCode = requestCode;
        this.data = data;

        if (this.onPreResult != null) {
            this.onPreResult.response(requestCode, resultCode, data)
                    .doOnComplete(new Action() {
                        @Override
                        public void run() throws Exception {
                            finish();
                        }
                    })
                    .subscribe();
        } else {
            finish();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (onResult != null)
            onResult.response(requestCode, resultCode, data);
    }

    static void setRequest(Request aRequest) {
        request = aRequest;
    }
}

一种是添加一个Fragment，在Fragment中获取回调，进行解耦合.参考本文所提到库的代码如下

import android.app.Fragment;
import android.content.Intent;

import androidx.annotation.NonNull;

/**
 * author:DingDeGao
 * time:2019-07-16-14:30
 * function: ReplaceFragment
 */
public class ReplaceFragment extends Fragment {

    static final int ACTIVITY_REQUEST_CODE = 100;
    static final int PERMISSION_REQUEST_CODE = 101;


    private IHandle iHandle;

    public void setIHandle(IHandle iHandle) {
        this.iHandle = iHandle;
    }

    public IHandle getIHandle(){
        return iHandle;
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode != ACTIVITY_REQUEST_CODE) return;
        if(iHandle != null){
            iHandle.onActivityResultHandle(resultCode,data);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode != PERMISSION_REQUEST_CODE) return;
        if(iHandle != null){
            iHandle.onRequestPermissionsResultHandle(getActivity(),permissions,grantResults);
        }
    }
}

RxActivityResult，RxPermission采用都是前者，而此处采用了后者，使用Fragment.

与RxActivityResult和RxPermission有什么不同？

不需要依赖RxJava，但也支持链式调用.
功能更丰富，两者结合，使用更加方便，并支持部分国产Rom的权限判断，跳转权限设置页面.
代码量少，可以选择拷贝代码直接放入项目.（核心代码不到 400行）
Fragment的方式占用资源更少.

开始使用（minSdkVersion >= 14）

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.DingProg:ActivityResultPermission:v0.0.1'
}

OnActivityResult

 Intent intent = new Intent(this, OnActivityResultActivity.class);
 //通过ActivityResultPermissionUtils 去启动Activity，并注册其回调
 ActivityResultPermissionUtils.startActivityForResult(this, intent).activityResult(new Listener.ResultListener() {
            @Override
        public void onResult(Intent data) {
            if (data != null) {
                String testStr = data.getStringExtra("test");
                Toast.makeText(MainActivity.this, "openActivity with result is:" + testStr, Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void onCancel() {
            Toast.makeText(MainActivity.this, "openActivity with result cancel", Toast.LENGTH_SHORT).show();
        }
 });

Permissions处理

ActivityResultPermissionUtils.requestPermissions(this, Manifest.permission.CAMERA).permissions(new Listener.PermissionResultListener() {
        @Override
        public void permissionDenied(String permission, boolean rationale) {
            //rationale if true 仅仅点击了禁止
            if(rationale){
                Toast.makeText(MainActivity.this, "Denied permission", Toast.LENGTH_SHORT).show();
            }else{
            //点击禁止权限，并不允许在弹出
                  Toast.makeText(MainActivity.this, "Denied permission with ask never", Toast.LENGTH_SHORT).show();
                PermissionGoSettingsPageUtils.go(MainActivity.this);
            }
        }

        @Override
        public void permissionGranted() {
            releaseCamera();
            try{
                camera = Camera.open(0);
                camera.setPreviewDisplay(surfaceView.getHolder());
                camera.startPreview();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    });

如果对于一些非正常Rom（如oppo，vivo手机），可以调用PermissionUtils.checkSelfPermissionsWhitNoNoramal(context,permissions);

请求权限时，调用ActivityResultPermissionUtils.requestPermissions(this, permission).permissionsWithoutCheck();

关于更多请查看sample ActivityResultPermission

如何优雅的处理Android 的OnActivityResult,RequestPermissions

序言

原理

与RxActivityResult和RxPermission有什么不同？

开始使用 （minSdkVersion >= 14）

OnActivityResult

Permissions处理

开始使用（minSdkVersion >= 14）