Android 微信支付集成过程

一、下载最新微信支付SDK demo 并运行过程
官网 https://pay.weixin.qq.com/wiki/doc/api/index.html
APP支付 https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_1
以下链接是当前可用链接(如若官方更新后请告知，感谢)

微信支付demo gradle版本(官方demo下载后无法运行，小编根据官方demo代码自己重新建的工程 )
https://download.csdn.net/download/w690333243/11008796
https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&id=open1419319167&token=&lang=zh_CN

eclipse demo
https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=11_1

新建的官方demo运行效果图

二、按照官方文档，在包名下新建 wxapi目录，并新建Activity WXPayEntryActivity（activity名必须是这个WXPayEntryActivity，在此activity中接收充值相关的结果回调）
在 app 下的build.gradle 中添加依赖

//compile 'com.tencent.mm.opensdk:wechat-sdk-android-with-mta:+'
 compile 'com.tencent.mm.opensdk:wechat-sdk-android-with-mta:5.3.1'

WXPayEntryActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import com.tencent.mm.opensdk.modelbase.BaseReq;
import com.tencent.mm.opensdk.modelbase.BaseResp;
import com.tencent.mm.opensdk.openapi.IWXAPI;
import com.tencent.mm.opensdk.openapi.IWXAPIEventHandler;
import com.tencent.mm.opensdk.openapi.WXAPIFactory;

public class WXPayEntryActivity extends BaseSwipeBackActivity implements IWXAPIEventHandler {
    private final String TAG = "WXPayEntryActivity";

    private IWXAPI api;

    @Override
    protected String getTitleText() {
        return null;
    }

    @Override
    protected void initViews(Bundle savedInstanceState) {
        api = WXAPIFactory.createWXAPI(this, App.appId);
        api.handleIntent(getIntent(), this);
    }

    @Override
    public int getContentViewId() {
        return R.layout.activity_wxpay_entry;
    }

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

    @Override
    public void onReq(BaseReq baseReq) {
        Log.i(TAG, "onReq: " + baseReq.toString());
    }


    /**
     * @auther WangQX
     * created at 2019/3/11 0011
     * https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9_12&index=2
     * errCode = -1  //签名错误、未注册APPID、项目设置APPID不正确、注册的APPID与设置的不匹配、其他异常等
     */
    @Override
    public void onResp(BaseResp baseResp) {
        Log.i(TAG, "onResp: ");
        Log.i(TAG, "onPayFinish,errCode=" + baseResp.errCode);
        if (baseResp.errCode == BaseResp.ErrCode.ERR_COMM) {
            showToast(getResources().getString(R.string.recharge_failed));
        } else if (baseResp.errCode == BaseResp.ErrCode.ERR_OK) {
            showToast(getResources().getString(R.string.recharge_successful));
        }
        startActivity(MyWalletActivity.class);
        finish();
    }
}

请求微信充值方法：
data是服务器返回的支付相关信息的json

//微信支付
    private void payWechat(final String data) {
        final IWXAPI msgApi = WXAPIFactory.createWXAPI(this, null);
        WeChatPayEntity weChatPayEntity = new Gson().fromJson(data, new TypeToken() {
        }.getType());
        if (weChatPayEntity == null) {
            return;
        }
        String appId = weChatPayEntity.getAppid();
        if (!TextUtils.isEmpty(appId)) {
            // 将该app注册到微信
            msgApi.registerApp(appId);
            PayReq req = new PayReq();
            App.appId = appId;
            req.appId = appId;
            req.partnerId = weChatPayEntity.getPartnerid();
            req.prepayId = weChatPayEntity.getPrepayid();
            req.packageValue = weChatPayEntity.getPackageX();
            req.nonceStr = weChatPayEntity.getNoncestr();
            req.timeStamp = weChatPayEntity.getTimestamp();
            req.sign = weChatPayEntity.getPaySign();
            boolean result = msgApi.sendReq(req);
            Log.d(TAG, "payWechat: result:"+result);
        }
    }

在 清单文件AndroidManifest.xml中添加

出现的问题：
android 的App只能在第一次调起微信支付界面，且支付不一定成功(没验证是否能支付成功，只看到第二次无法调起支付界面了)，原因:微信开放平台中填写的应用相关的包名、签名不正确
android studio 下 Terminal窗口中输入如下命令

keytool -list -keystore -v -keystore C:\Users\Administrator\Desktop\test.jks   查看签名

https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_5#
https://blog.csdn.net/xuchao_blog/article/details/58135338
https://blog.csdn.net/afanbaby/article/details/60885642
https://blog.csdn.net/Jarry_JR/article/details/80843901
https://blog.csdn.net/m_sicily/article/details/82493171
https://blog.csdn.net/u010083127/article/details/78968761
https://blog.csdn.net/u012552275/article/details/78758571/
https://blog.csdn.net/xinluqishi123/article/details/52234002
https://blog.csdn.net/li438730745/article/details/80494155
https://blog.csdn.net/ws1836300/article/details/53893102
https://www.jianshu.com/p/81c6c7d3390a
https://blog.csdn.net/hongcha36/article/details/78743535
https://blog.csdn.net/catshitone/article/details/73614321
https://blog.csdn.net/CLinuxF/article/details/79456207
https://blog.csdn.net/jay100500/article/details/52956000