android 简单实现，微信第三方登录

能拿到微信用户的用户名，头像，性别，城市等数据.........

讲下遇到的坑，不注意看官方API的后果。

微信常见问题：

https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&id=open1419318060&token=&lang=zh_CN

android 移动接入指南: https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&id=1417751808&token=&lang=zh_CN

android 移动应用微信登录开发指南:https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&id=open1419317851&token=&lang=zh_CN

我就是使用了和开发平台填写不一致的签名，所以一直启动不了微信那个授权界面。还有就是微信关闭了或者也没后台运行，点两下登录，才能掉起微信的授权界面，具体什么原因没深究，好像官方API有解释。

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看完API，照着android接入指南搭好环境之后，就可以写代码了，微信第三方登录还是比较简单的，官方也说了就三步：

第一步：获得code

 注册到微信：这个必须要做

发送请求，掉起微信授权界面：

发送请求会有返回参数，是一串字符，那个就是code，详细的参数请看官方文档，这样就完成了三步中的第一步了。

第二步，获得token

//请求Token
private void getAccessToken(String code) {
    String url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid="
            + GlobalConstant.WX_APPID
            + "&secret=" + GlobalConstant.WX_SECRET
            + "&code=" + code
            + "&grant_type=authorization_code";

    VolleyRequest.newStringRequest(Request.Method.GET, url, null, new Response.Listener() {
        @Override
        public void onResponse(JSONObject response) {
            try {
                access_token = response.getString("access_token");
                expires_in = response.getInt("expires_in");
                refresh_token = response.getString("refresh_token");
                openid = response.getString("openid");
                scope = response.getString("scope");
                unionid = response.getString("unionid");
                Log.e("ljj", "access_token: " + access_token + "\n" + "expires_in: " + expires_in + "\n"
                        + "refresh_token: " + refresh_token + "\n"
                        + "openid: " + openid + "\n" + "scope: " + scope + "\n" + "unionid: " + unionid);

            } catch (JSONException e) {
                e.printStackTrace();
            }
        //发起用户详细信息请求
        getUser(access_token, openid);

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e("ljj", "error: " + error);
        }
    });
}

这样会有一大段的json返回给你，要自己解析，拿出需要的token和openid，在第三步中作为参数发出去

第三步：获得用户详细信息

在第二步中，写了一个方法直接发送了请求

public void getUser(String access_token, String openid) {
    String url = "https://api.weixin.qq.com/sns/userinfo?access_token="
            + access_token
            + "&openid=" + openid;
    Log.e("hg", "onResponse: " + url);

    VolleyRequest.newStringRequest(Request.Method.GET, url, null, new Response.Listener() {
        @Override
        public void onResponse(JSONObject response) {

            //获取的微信用户信息，有头像，性别，名字，城市等等；
            Log.e("hg", "onResponse: " + response);
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e("ljj", "error: " + error);
        }
    });
}

虽然是新手，以前没写过播客，但CSDN这个博客编辑器，有点难操作，挺浪费时间的，一点都不灵性......

直接上代码吧，一共有三步，除了第一步写在了其他界面，第二步，第三步，均写在了wxapi文件下的WXEntryActivity 这个类里面了，下面这个是这个类的由来，在官方文档  android移动接入指南里面有介绍，要按照他的规范写。

第二步和第三步的源码：

package com.hanfang.anyfit.wxapi;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.hanfang.anyfit.AnyfitApplication;
import com.hanfang.anyfit.activity.BaseActivity;
import com.hanfang.anyfit.httputil.httpUtils.VolleyRequest;
import com.hanfang.anyfit.utils.GlobalConstant;
import com.tencent.mm.opensdk.modelbase.BaseReq;
import com.tencent.mm.opensdk.modelbase.BaseResp;
import com.tencent.mm.opensdk.modelmsg.SendAuth;
import com.tencent.mm.opensdk.openapi.IWXAPI;
import com.tencent.mm.opensdk.openapi.IWXAPIEventHandler;


import org.json.JSONException;
import org.json.JSONObject;

/**
 * Created by Administrator on 2017/6/18.
 */

public class WXEntryActivity extends BaseActivity implements IWXAPIEventHandler {
    private IWXAPI api;

    static String access_token;
    static int expires_in;
    static String refresh_token;
    static String openid;
    static String scope;
    static String unionid;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportActionBar();
        api = AnyfitApplication.mApp.api;
        api.handleIntent(getIntent(), this);

    }

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

    //微信发送请求到第三方应用，会用到该方法
    @Override
    public void onReq(BaseReq baseReq) {

    }

    //第三方应用发送到微信的请求处理后的响应结果，会回调到该方法
    @Override
    public void onResp(BaseResp baseResp) {
        switch (baseResp.errCode) {
            case BaseResp.ErrCode.ERR_OK:
                Toast.makeText(this, "发送成功", Toast.LENGTH_SHORT).show();
                String code = ((SendAuth.Resp) baseResp).code;
                Log.e("ljj", "wx:" + code);

                //请求Token
                getAccessToken(code);
                
                finish();

                break;
            case BaseResp.ErrCode.ERR_AUTH_DENIED:
                Toast.makeText(this, "发送被拒绝", Toast.LENGTH_SHORT).show();
                break;
            case BaseResp.ErrCode.ERR_USER_CANCEL:
                Toast.makeText(this, "发送取消", Toast.LENGTH_SHORT).show();
                break;
            case BaseResp.ErrCode.ERR_UNSUPPORT:
                Toast.makeText(this, "不支持错误", Toast.LENGTH_SHORT).show();
                break;
            default:
                Toast.makeText(this, "发送返回", Toast.LENGTH_SHORT).show();
                break;

        }
    }

    //请求Token
    private void getAccessToken(String code) {
        String url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid="
                + GlobalConstant.WX_APPID
                + "&secret=" + GlobalConstant.WX_SECRET
                + "&code=" + code
                + "&grant_type=authorization_code";

        VolleyRequest.newStringRequest(Request.Method.GET, url, null, new Response.Listener() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    access_token = response.getString("access_token");
                    expires_in = response.getInt("expires_in");
                    refresh_token = response.getString("refresh_token");
                    openid = response.getString("openid");
                    scope = response.getString("scope");
                    unionid = response.getString("unionid");
                    Log.e("ljj", "access_token: " + access_token + "\n" + "expires_in: " + expires_in + "\n"
                            + "refresh_token: " + refresh_token + "\n"
                            + "openid: " + openid + "\n" + "scope: " + scope + "\n" + "unionid: " + unionid);

                } catch (JSONException e) {
                    e.printStackTrace();
                }
                getUser(access_token, openid);
                Log.e("ljj", "onResponse: " + response);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("ljj", "error: " + error);
            }
        });
    }

    public void getUser(String access_token, String openid) {
        String url = "https://api.weixin.qq.com/sns/userinfo?access_token="
                + access_token
                + "&openid=" + openid;
        Log.e("hg", "onResponse: " + url);

        VolleyRequest.newStringRequest(Request.Method.GET, url, null, new Response.Listener() {
            @Override
            public void onResponse(JSONObject response) {
                //获取的微信用户信息，有头像，性别，名字，城市等等；
                Log.e("hg", "onResponse: " + response);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("ljj", "error: " + error);
            }
        });
    }
}

新手上路，有哪里不对的，望指出。