Android集成第三方微信登錄

第一步：

在微信開放平台創建安卓應用，需要輸入的包名和簽名就不用再提吧，不知道的自行百度。 
應用創建完畢后會得到兩個值：AppID、AppSecret，用這兩個值來請求微信。 
然后去微信開放平台的資源中心 ，選擇安卓資源包 ，如圖： 

注意：輸入的包名和簽名要和項目中的一致！

第二步：

將安卓資源包中的libammsdk.jar 導入到項目中的libs文件夾下面。 
並在項目中的創建一個包 ，包名必須為 package+wxapi，比如你的包名是com.xxx.Android，那就要創建一個 com.xxx.android.wxapi。然后在這個 包下面 建一個類 ，類名為WXEntryActivity。 
在AndroidManifest.xml 注冊這個類

    <activity
            android:name="com.xxx.android.wxapi.WXEntryActivity"
            android:configChanges="keyboardHidden|orientation|screenSize"
            android:exported="true"
            android:launchMode="singleTop"
            android:screenOrientation="portrait"
            android:theme="@android:style/Theme.Translucent.NoTitleBar" >
     </activity>

下面是WXEntryActivity中的代碼：

public class WXEntryActivity extends Activity implements IWXAPIEventHandler {
    private IWXAPI api;
    private BaseResp resp = null;
    private String WX_APP_ID = "創建應用后得到的APP_ID";
    // 獲取第一步的code后，請求以下鏈接獲取access_token
    private String GetCodeRequest = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code";
    // 獲取用戶個人信息
    private String GetUserInfo = "https://api.weixin.qq.com/sns/userinfo?access_token=ACCESS_TOKEN&openid=OPENID";
    private String WX_APP_SECRET = "創建應用后得到的APP_SECRET";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        api = WXAPIFactory.createWXAPI(this, WX_APP_ID, false);
        api.handleIntent(getIntent(), this);
    }

    // 微信發送請求到第三方應用時，會回調到該方法
    @Override
    public void onReq(BaseReq req) {
        finish();
    }

    // 第三方應用發送到微信的請求處理后的響應結果，會回調到該方法
    @Override
    public void onResp(BaseResp resp) {
        String result = "";
        if (resp != null) {
            resp = resp;
        }
        switch (resp.errCode) {
        case BaseResp.ErrCode.ERR_OK:
            result = "發送成功";
            Toast.makeText(this, result, Toast.LENGTH_LONG).show();
            String code = ((SendAuth.Resp) resp).code;

            /*
             * 將你前面得到的AppID、AppSecret、code，拼接成URL 獲取access_token等等的信息(微信)
             */
            String get_access_token = getCodeRequest(code);
            AsyncHttpClient client = new AsyncHttpClient();
            client.post(get_access_token, new JsonHttpResponseHandler() {
                @Override
                public void onSuccess(int statusCode, JSONObject response) {
                    // TODO Auto-generated method stub
                    super.onSuccess(statusCode, response);
                    try {


                        if (!response.equals("")) {
                            String access_token = response
                                    .getString("access_token");
                            String openid = response.getString("openid");
                            String get_user_info_url = getUserInfo(
                                    access_token, openid);
                            getUserInfo(get_user_info_url);
                        }

                    } catch (Exception e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            });

            finish();
            break;
        case BaseResp.ErrCode.ERR_USER_CANCEL:
            result = "發送取消";
            Toast.makeText(this, result, Toast.LENGTH_LONG).show();
            finish();
            break;
        case BaseResp.ErrCode.ERR_AUTH_DENIED:
            result = "發送被拒絕";
            Toast.makeText(this, result, Toast.LENGTH_LONG).show();
            finish();
            break;
        default:
            result = "發送返回";
            Toast.makeText(this, result, Toast.LENGTH_LONG).show();
            finish();
            break;
        }
    }

    /**
     * 通過拼接的用戶信息url獲取用戶信息
     * 
     * @param user_info_url
     */
    private void getUserInfo(String user_info_url) {
        AsyncHttpClient client = new AsyncHttpClient();
        client.get(user_info_url, new JsonHttpResponseHandler() {
            @Override
            public void onSuccess(int statusCode, JSONObject response) {
                // TODO Auto-generated method stub
                super.onSuccess(statusCode, response);
                try {

                    System.out.println("獲取用戶信息:" + response);

                    if (!response.equals("")) {
                        String openid = response.getString("openid");
                        String nickname = response.getString("nickname");
                        String headimgurl = response.getString("headimgurl");

                    }

                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        });
    }

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

    /**
     * 獲取access_token的URL（微信）
     * 
     * @param code
     *            授權時，微信回調給的
     * @return URL
     */
    private String getCodeRequest(String code) {
        String result = null;
        GetCodeRequest = GetCodeRequest.replace("APPID",
                urlEnodeUTF8(WX_APP_ID));
        GetCodeRequest = GetCodeRequest.replace("SECRET",
                urlEnodeUTF8(WX_APP_SECRET));
        GetCodeRequest = GetCodeRequest.replace("CODE", urlEnodeUTF8(code));
        result = GetCodeRequest;
        return result;
    }

    /**
     * 獲取用戶個人信息的URL（微信）
     * 
     * @param access_token
     *            獲取access_token時給的
     * @param openid
     *            獲取access_token時給的
     * @return URL
     */
    private String getUserInfo(String access_token, String openid) {
        String result = null;
        GetUserInfo = GetUserInfo.replace("ACCESS_TOKEN",
                urlEnodeUTF8(access_token));
        GetUserInfo = GetUserInfo.replace("OPENID", urlEnodeUTF8(openid));
        result = GetUserInfo;
        return result;
    }

    private String urlEnodeUTF8(String str) {
        String result = str;
        try {
            result = URLEncoder.encode(str, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

}

第三步：

在Activity中調起訪問微信

public class LoginActivity extends Activity implements OnClickListener {

    private Button login;

    // 微信登錄
    private static IWXAPI WXapi;
    private String WX_APP_ID = "創建應用后得到的APP_ID";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        // 啟動activity時不自動彈出軟鍵盤
        getWindow().setSoftInputMode(
                WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.login);
        init();
    }

    private void init() {
        login = (Button) findViewById(R.id.bt_login);

        login.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {

        case R.id.login:
            WXLogin();
            break;
        default:
            break;
        }

    }

    /**
     * 登錄微信
     */
    private void WXLogin() {
        WXapi = WXAPIFactory.createWXAPI(this, WX_APP_ID, true);
        WXapi.registerApp(WX_APP_ID);
        SendAuth.Req req = new SendAuth.Req();
        req.scope = "snsapi_userinfo";
        req.state = "wechat_sdk_demo";
        WXapi.sendReq(req);

    }

}