1.创建应用

2.进入应用详情，填写应用的签名与包名

https://res.wx.qq.com/open/zh_CN/htmledition/res/dev/download/sdk/Gen_Signature_Android2.apk

填写应用相关的包名，得到相关签名

• 2.这里必须要填写，否则导致后期调用接口出错。

3.回到应用进行相关的代码配置

4.调用接口的流程

    // send oauth request
    Final SendAuth.Req req = new SendAuth.Req();
    req.scope = "snsapi_userinfo";
    req.state = "wechat_sdk_demo_test";
    api.sendReq(req);

2. 授权登录之后，进行回调根据code获取access_token
   https://api.weixin.qq.com/sns/oauth2/access_token?appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code

返回说明

{ 
"access_token":"ACCESS_TOKEN", 
"expires_in":7200, 
"refresh_token":"REFRESH_TOKEN",
"openid":"OPENID", 
"scope":"SCOPE",
"unionid":"o6_bmasdasdsad6_2sgVt7hMZOPfL"
}

3. 刷新access_token有效期
   1.access_token过期，则进行通过refresh_token进行刷新操作
   2.access_token未过期，重新调用接口，access_token不会改变，有效期会有所变动

注意： refresh_token拥有较长的有效期（30天），当refresh_token失效的后，需要用户重新授权。

请求方法

获取第一步的code后，请求以下链接进行refresh_token：
https://api.weixin.qq.com/sns/oauth2/refresh_token?appid=APPID&grant_type=refresh_token&refresh_token=REFRESH_TOKEN

返回说明

{
"access_token":"ACCESS_TOKEN",
"expires_in":7200,
"refresh_token":"REFRESH_TOKEN",
"openid":"OPENID",
"scope":"SCOPE"
}

4. 检验授权凭证（access_token）是否有效
   https://api.weixin.qq.com/sns/auth?access_token=ACCESS_TOKEN&openid=OPENID

返回说明

{
"errcode":0,"errmsg":"ok"
}

5. 根据access_token调用接口，获取用户个人信息（UnionID机制）
   https://api.weixin.qq.com/sns/userinfo?access_token=ACCESS_TOKEN&openid=OPENID

返回说明

{
"openid":"OPENID",
"nickname":"NICKNAME",
"sex":1,
"province":"PROVINCE",
"city":"CITY",
"country":"COUNTRY",
"headimgurl": "http://wx.qlogo.cn/mmopen/g3MonUZtNHkdmzicIlibx6iaFqAc56vxLSUfpb6n5WKSYVY0ChQKkiaJSgQ1dZuTOgvLLrhJbERQQ4eMsv84eavHiaiceqxibJxCfHe/0",
"privilege":[
"PRIVILEGE1",
"PRIVILEGE2"
],
"unionid": " o6_bmasdasdsad6_2sgVt7hMZOPfL"
}

建议：

开发者最好保存unionID信息，以便以后在不同应用之间进行用户信息互通。

• 同时需要注意的代码块
• 1.要在Androidminfiest.xml配置

AppID：相当于包名（package）
  <activity
            android:name="AppID.wxapi.WXEntryActivity"
            android:exported="true"
            android:label="@string/app_name"
            android:launchMode="singleTask"
            android:taskAffinity="com.jifenzhi.android"
            android:theme="@android:style/Theme.Translucent.NoTitleBar" />

• 2.需要将WXEntryActivity放到路径名AppID.wxapi.WXEntryActivity包下

public class WXEntryActivity extends Activity implements IWXAPIEventHandler {

    private IWXAPI api;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        api = WXAPIFactory.createWXAPI(this, HttpsManager.WEIXIN_APP_ID, false);
        try {
            Intent intent = getIntent();
            api.handleIntent(intent, this);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        setIntent(intent);
        api.handleIntent(intent, this);
    }

    @Override
    public void onReq(BaseReq req) {
        switch (req.getType()) {
            case ConstantsAPI.COMMAND_GETMESSAGE_FROM_WX:
//                goToGetMsg();
                break;
            case ConstantsAPI.COMMAND_SHOWMESSAGE_FROM_WX:
//                goToShowMsg((ShowMessageFromWX.Req) req);
                break;
            default:
                break;
        }
        finish();
    }

    @Override
    public void onResp(BaseResp resp) {
        int result = 0;
        switch (resp.errCode) {
            case BaseResp.ErrCode.ERR_OK:
                if (resp.getType() == ConstantsAPI.COMMAND_SENDAUTH) {
                    SendAuth.Resp authResp = (SendAuth.Resp) resp;
                    final String code = authResp.code;
                    Observable.just(new HashMapNull())
                            .concatMap((Function<HashMapNull, ObservableSource<?>>) hashMapNull -> {
                                hashMapNull.put("code", code);
                                hashMapNull.put("grant_type", "authorization_code");
                                hashMapNull.put("appid", WEIXIN_APP_ID);
                                hashMapNull.put("secret", WEIXIN_APP_SECRET);
                                return HttpsManager.getInstance().apiService.getWxAccessToken("https://api.weixin.qq.com/sns/oauth2/access_token", hashMapNull);
                            })
                            .compose(RxHelper.observableIO2Main(this))
                            .subscribe(new BaseObserver<Object>() {
                                @Override
                                public void onBaseNext(Object data) {
                                    WeiXinTokenModel weiXinTokenModel = (WeiXinTokenModel) data;
                                    Intent intent = new Intent(WXEntryActivity.this, LoginActivity.class);
                                    intent.putExtra("weiXinTokenModel", weiXinTokenModel);
                                    startActivity(intent);
                                }

                                @Override
                                public void onBaseError(String message) {

                                }

                            });
                }
                break;
            case BaseResp.ErrCode.ERR_USER_CANCEL:
                result = R.string.errcode_cancel;
                break;
            case BaseResp.ErrCode.ERR_AUTH_DENIED:
                result = R.string.errcode_deny;
                break;
            case BaseResp.ErrCode.ERR_UNSUPPORT:
                result = R.string.errcode_unsupported;
                break;
            default:
                result = R.string.errcode_unknown;
                break;
        }
        finish();
    }

}

• 3.当应用进行授权登录之后，应用进行回调通过WXEntryActivity类得到code值，并通过code请求接口得到access_token，再通过access_token与openid，请求用户信息接口得到用户信息，并将其保存下来