Android笔记：集成原生微信授权获取用户信息登录

其实两年前做过这个功能，项目最近需要加上获取微信用户信息的需求，索性我就写成一篇文章，当做笔记
我在项目中用到的是点击一个按钮发起微信授权请求的需求，首先判断是否安装微信，如果安装微信则进行用户授权，授权成功之后通过微信提供的接口获取openID等用户信息，然后做自己的业务：

1、 Android端要使用微信登录，必须在微信开发平台创建APP并且审核通过，得到appid和secret
2、 依赖微信SDK

dependencies {
compile ‘com.tencent.mm.opensdk:wechat-sdk-android-without-mta:+’
}

3、添加权限

<uses-permission android:name="android.permission.INTERNET"/>  
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>  
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>  
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>  
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 

4、注册到微信

iwxapi = WXAPIFactory.createWXAPI(this, Constant.APP_ID, true);
 iwxapi.registerApp(Constant.APP_ID);

5、 判断是否安装微信，已安装则发起授权请求

if (!iwxapi.isWXAppInstalled()) {
     Intent intent = new Intent(this, MyDialogActivity.class);
     startActivity(intent);
  } else {
      final SendAuth.Req req = new SendAuth.Req();
       req.scope = "snsapi_userinfo";
       req.state = "wechat_sdk_demo_test";
       iwxapi.sendReq(req);
}

6、在包名下创建wxapi包和WXEntryActivity类（继承Activity并实现IWXAPIEventHandler接口）WXEntryActivity是微信回调的一个类，通常给个透明的主题或者处理完业务逻辑就直接finish。需要在回调中拿到code，然后再根据code去获取AccessToken，然后再根据AccessToken和OpenId去获取UserInfo。
代码如下：

public class WXEntryActivity extends AppCompatActivity implements IWXAPIEventHandler {
    private IWXAPI iwxapi;
    private String unionid;
    private String openid;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportActionBar().hide();
//        // 隐藏状态栏
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        //接收到分享以及登录的intent传递handleIntent方法，处理结果
        iwxapi = WXAPIFactory.createWXAPI(this, Constant.APP_ID, false);
        iwxapi.handleIntent(getIntent(), this);

    }


    @Override
    public void onReq(BaseReq baseReq) {
    }


    //请求回调结果处理
    @Override
    public void onResp(BaseResp baseResp) {
        //登录回调
        switch (baseResp.errCode) {
            case BaseResp.ErrCode.ERR_OK:
                String code = ((SendAuth.Resp) baseResp).code;
                //获取用户信息
                getAccessToken(code);
                break;
            case BaseResp.ErrCode.ERR_AUTH_DENIED://用户拒绝授权
                finish();
                break;
            case BaseResp.ErrCode.ERR_USER_CANCEL://用户取消
                finish();
                break;
            default:
                finish();
                break;
        }
    }

    private void getAccessToken(String code) {
        //获取授权
        StringBuffer loginUrl = new StringBuffer();
        loginUrl.append("https://api.weixin.qq.com/sns/oauth2/access_token")
                .append("?appid=")
                .append(Constant.APP_ID)
                .append("&secret=")
                .append(Constant.SECRET)
                .append("&code=")
                .append(code)
                .append("&grant_type=authorization_code");
        OkHttpUtils.ResultCallback<String> resultCallback = new OkHttpUtils.ResultCallback<String>() {
            @Override
            public void onSuccess(String response) {
                String access = null;
                String openId = null;
                try {
                    JSONObject jsonObject = new JSONObject(response);
                    access = jsonObject.getString("access_token");
                    openId = jsonObject.getString("openid");
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                //获取个人信息
                String getUserInfo = "https://api.weixin.qq.com/sns/userinfo?access_token=" + access + "&openid=" + openId;
                OkHttpUtils.ResultCallback<String> reCallback = new OkHttpUtils.ResultCallback<String>() {
                    @Override
                    public void onSuccess(String responses) {

                        String nickName = null;
                        String sex = null;
                        String city = null;
                        String province = null;
                        String country = null;
                        String headimgurl = null;
                        try {
                            JSONObject jsonObject = new JSONObject(responses);

                            openid = jsonObject.getString("openid");
                            nickName = jsonObject.getString("nickname");
                            sex = jsonObject.getString("sex");
                            city = jsonObject.getString("city");
                            province = jsonObject.getString("province");
                            country = jsonObject.getString("country");
                            headimgurl = jsonObject.getString("headimgurl");
                            unionid = jsonObject.getString("unionid");
                            loadNetData(1, openid, nickName, sex, province,
                                    city, country, headimgurl, unionid);

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                    }

                    @Override
                    public void onFailure(Exception e) {
                        Toast.makeText(WXEntryActivity.this, "登录失败", Toast.LENGTH_SHORT).show();
                        finish();
                    }
                };
                OkHttpUtils.get(getUserInfo, reCallback);
            }

            @Override
            public void onFailure(Exception e) {
                Toast.makeText(WXEntryActivity.this, "登录失败", Toast.LENGTH_SHORT).show();
                finish();
            }
        };
        OkHttpUtils.get(loginUrl.toString(), resultCallback);
    }

    @Override
    protected void onPause() {
        overridePendingTransition(0, 0);
        super.onPause();
    }



}

这里贴上OkHttpUtils的代码便于大家使用：

public class OkHttpUtils {

   private static OkHttpUtils mInstance;
   private OkHttpClient mOkHttpClient;
   private Handler mDelivery;
   private Gson mGson;

   private OkHttpUtils() {
       mOkHttpClient = new OkHttpClient.Builder()
               .connectTimeout(10, TimeUnit.SECONDS)
               .writeTimeout(10, TimeUnit.SECONDS)
               .readTimeout(30, TimeUnit.SECONDS)
               .build();
       mGson = new Gson();
       mDelivery = new Handler(Looper.getMainLooper());
   }

   private synchronized static OkHttpUtils getmInstance() {
       if (mInstance == null) {
           mInstance = new OkHttpUtils();
       }
       return mInstance;
   }

   private void getRequest(String url, final ResultCallback callback) {
       final Request request = new Request.Builder().url(url).build();
       deliveryResult(callback, request);
   }

   private void postRequest(String url, final ResultCallback callback, List<Param> params) {
       Request request = buildPostRequest(url, params);
       deliveryResult(callback, request);
   }

   /**
    * 处理结果
    * @param callback
    * @param request
    */
   private void deliveryResult(final ResultCallback callback, Request request) {

       mOkHttpClient.newCall(request).enqueue(new Callback() {
           @Override
           public void onFailure(Call call, IOException e) {
               sendFailCallback(callback, e);
           }

           @Override
           public void onResponse(Call call, Response response) throws IOException {
               try {
                   String str = response.body().string();
                   if (callback.mType == String.class) {
                       /**
                        * 返回字符串
                        */
                       sendSuccessCallBack(callback, str);
                   } else {
                       /**
                        * 这里处理解析返回对象
                        */
                       Object object = mGson.fromJson(str, callback.mType);
                       sendSuccessCallBack(callback, object);

                   }
               } catch (final Exception e) {
//                    LogUtils.e(TAG, "convert json failure", e);
                   sendFailCallback(callback, e);
               }
           }
       });
   }

   private void sendFailCallback(final ResultCallback callback, final Exception e) {
       mDelivery.post(new Runnable() {
           @Override
           public void run() {
               if (callback != null) {
                   callback.onFailure(e);
               }
           }
       });
   }

   private void sendSuccessCallBack(final ResultCallback callback, final Object obj) {
       mDelivery.post(new Runnable() {
           @Override
           public void run() {
               if (callback != null) {
                   callback.onSuccess(obj);
               }
           }
       });
   }

   private Request buildPostRequest(String url, List<Param> params) {
       FormBody.Builder builder= new FormBody.Builder();
       for (Param param : params) {
           builder.add(param.key, param.value);
       }
       RequestBody requestBody = builder.build();
       return new Request.Builder().url(url).post(requestBody).build();
   }


   /**********************对外接口************************/

   /**
    * get请求
    * @param url  请求url
    * @param callback  请求回调
    */
   public static void get(String url, ResultCallback callback) {
       getmInstance().getRequest(url, callback);
   }

   /**
    * post请求
    * @param url       请求url
    * @param callback  请求回调
    * @param params    请求参数
    */
   public static void post(String url, final ResultCallback callback, List<Param> params) {
       getmInstance().postRequest(url, callback, params);
   }

   /**
    * http请求回调类,回调方法在UI线程中执行
    * @param <T>
    */
   public static abstract class ResultCallback<T> {

       Type mType;

       public ResultCallback(){
           mType = getSuperclassTypeParameter(getClass());
       }

       static Type getSuperclassTypeParameter(Class<?> subclass) {
           Type superclass = subclass.getGenericSuperclass();
           if (superclass instanceof Class) {
               throw new RuntimeException("Missing type parameter.");
           }
           ParameterizedType parameterized = (ParameterizedType) superclass;
           return $Gson$Types.canonicalize(parameterized.getActualTypeArguments()[0]);
       }

       /**
        * 请求成功回调
        * @param response
        */
       public abstract void onSuccess(T response);

       /**
        * 请求失败回调
        * @param e
        */
       public abstract void onFailure(Exception e);
   }

   /**
    * post请求参数类   这里可以根据项目抽取成泛型
    */
   public static class Param {

       String key;
       String value;

       public Param() {
       }

       public Param(String key, String value) {
           this.key = key;
           this.value = value;
       }

   }


}

到此登录授权就结束了，大家有什么不懂的，或者遇到什么问题可在下方留言。