SDK之：微信登录

微信登录接入步骤：

事先准备：
以下两个字段在微信开发平台会有，AppSecret在官网上不会储存了，自行保管，但是可以重置
AppID：xxxxxx
AppSecret：yyyyyy

依赖：
compile 'com.tencent.mm.opensdk:wechat-sdk-android-with-mta:+'

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"/>

WXEntryActivity注册：对于微信登录来说，该类只能放在(包名.wxapi）目录下
<activity
android:name=".wxapi.WXEntryActivity"
android:configChanges="keyboardHidden|orientation|screenSize"
android:exported="true"
android:screenOrientation="portrait"
android:theme="@android:style/Theme.Translucent.NoTitleBar" />

WXEntryActivity类如下：

public class WXEntryActivity extends FragmentActivity implements IWXAPIEventHandler {

private IWXAPI api;

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

    api = WXAPIFactory.createWXAPI(this, AppID, false);
    //下方注册代码若不行，可以放在BaseApplication中的onCreate()；方法中或者是登录页面的Activity中注册
    api.registerApp(AppID);

    api.handleIntent(getIntent(), this);
}

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    setIntent(intent);
    api.handleIntent(intent, this);
}
//微信发送的请求将回调以下方法
@Override
public void onReq(BaseReq req) {
    switch (req.getType()) {
        case ConstantsAPI.COMMAND_GETMESSAGE_FROM_WX:

            break;
        case ConstantsAPI.COMMAND_SHOWMESSAGE_FROM_WX:

            break;
        default:
            break;
    }
}
//发送到微信请求的响应结果将回调以下方法
@Override
public void onResp(BaseResp resp) {
    switch (resp.errCode) {
        case BaseResp.ErrCode.ERR_OK:
            //获取回传的code（临时票据参数）
            String code = ((SendAuth.Resp) resp).code;
            finish();
            //保存微信的用户信息（该方法里面是把信息提供给了接口）code加上APPID和AppSecret,通过API 换取access_token
            getAccessToken(WXEntryActivity.this, code);
            break;
        case BaseResp.ErrCode.ERR_USER_CANCEL:
            //取消
            break;
        case BaseResp.ErrCode.ERR_AUTH_DENIED:
            //发送被拒绝
            break;
        default:
            break;
    }
}
}

步骤一：点击微信登录后，首先调用微信登录授权接入

//点击微信登录的按钮
wxImage.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        loginWx();
    }
});

/**
* 微信登录授权接入
*/
public static void loginWx() {
    final SendAuth.Req req = new SendAuth.Req();
    req.scope = "snsapi_userinfo";
    req.state = "wechat_sdk_demo_test";
    api.sendReq(req);
}

步骤二：授权通过后，在WXEntryActivity中的onResp()方法中获取微信回传的临时票据参数code，该参数的作用在于与AppID和AppSecret获取openid 和access_token。

/**
 * 获取微信用户的openid和access_token(接口凭证)
 */
public static void getAccessToken(final Activity activity, String code) {
    if (!TextUtils.isEmpty(code) && !code.equals("null")) {
        final OkHttpClient okHttpClient = new OkHttpClient();
        String accessCodeUrl = "https://api.weixin.qq.com/sns/oauth2/access_token";
        HashMap<String, String> map = new HashMap<>();
        map.put("appid", AppID);
        map.put("secret", AppSecret);
        map.put("code", code);
        map.put("grant_type", "authorization_code");
        String paramStr = getParams(accessCodeUrl, map);//获取带参数的url
        Request request = new Request.Builder().url(paramStr).build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {//带上请求之后的回传
            @Override
            public void onFailure(Call call, IOException e) {

            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String value = response.body().string();
                try {
                    JSONObject object = new JSONObject(value);
                    //该回传的值中包含openid和access_token字段
                    String openid = object.getString("openid");
                    String access_token = object.getString("access_token");
                    //获取到以上字段之后就是获取用户的相关信息
                    getUserInfo(activity, okHttpClient, openid, access_token);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    } 
}

其中，getUserInfo()为获取用户信息的方法，通过openid 和access_token参数获取用户信息：

/**
 * 获取微信用户信息
 * @param activity
 * @param okHttpClient
 * @param openid
 * @param access_token
 */
public static void getUserInfo(final Activity activity, OkHttpClient okHttpClient, String openid, String access_token) {
    HashMap<String, String> param = new HashMap<String, String>();
    param.put("openid", openid);
    param.put("access_token", access_token);
    String paramsStr = HttpManager.getParams("https://api.weixin.qq.com/sns/userinfo", param);
    Request request = new Request.Builder().url(paramsStr).build();
    Call call = okHttpClient.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {

        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String value = response.body().string();
            try {
                JSONObject object = new JSONObject(value);
                activity.finish();
                JSONObject valueObject = new JSONObject();
                //该回传的值中包含用户信息等几个字段
                valueObject.put("openId", object.getString("openid"));
                valueObject.put("nickname", object.getString("nickname"));
                valueObject.put("avatar", object.getString("headimgurl"));
                valueObject.put("unionid", object.getString("unionid"));
                int sex = object.getInt("sex");
                if (sex == 1) {
                    valueObject.put("gender", "男");
                } else {
                    valueObject.put("gender", "女");
                }
                //此时valueObject里包含了用户各字段的信息
                authLogin(valueObject);
            } catch (Exception e) {
                  e.printStackTrace();
            }
      }
    });
}

其中getParams()为获取带有参数的url拼接：

/**
 * 获取带有参数的url拼接
 * @param url
 * @param param
 */
public static String getParams(String url, HashMap<String, String> param) {
    String getparams = "";
    for (Map.Entry<String, String> entry : param.entrySet()) {
        getparams = getparams + entry.getKey() + "=" + entry.getValue() + "&";
    }
    if (getparams.length() > 1) {
        getparams = getparams.substring(0, getparams.length() - 1);
    }
    url = url + "?" + getparams;
    LogUtil.logI("url:" + url);
    return url;
}

其中 authLogin()为微信登录请求后台API的方法：

 /**
 * 微信登录的请求接口
 * @param openId
 * @param nickname
 * @param avatar
 * @param userType
 * @param unionid
 */
public void authLogin(JSONObject jsonObject) {
    String nickname = jsonObject.getString("nickname");
    String openId = jsonObject.getString("openId");
    String avatar = jsonObject.getString("avatar");
    String unionid = jsonObject.getString("unionid");
    //请求登录的具体字段应根据后台来定
    HashMap<String, String> param = new HashMap<>();
    param.put("openId", openId);//openid授权用户唯一标识
    param.put("nickname", nickname);//用户名称
    param.put("avatar", avatar);//用户头像地址
    param.put("userType", “微信登录”);//登录类型
    param.put("unionId", unionid);//当且仅当该移动应用已获得该用户的userinfo授权时，才会出现该字段
    manager.post(NetworkAPI.Oauth_Login, new HttpCallback() {
        @Override
        public void onSuccess(int code, String value, String msg, String pageStr) {
            if (code == RequestSucceed) {
                //登录成功之后存下用户信息类
                spUtil.putString("user", value);
                //用户信息实体类
                UserBean user = GsonUtil.toBean(value, UserBean.class);
                
                //此时登录已成功！！
            }
        }

        @Override
        public void onFailure(String value) {
         
        }
    }, param);
}

结束。