获取微信发票功能

流程概述：
发起请求：初始化IWXAPI->IWXAPI.sendReq(ChooseCardFromWXCardPackage.Req)
接收：需要WXEntryActivity->onResp(BaseResp resp){ChooseCardFromWXCardPackage.Resp cardResp = (ChooseCardFromWXCardPackage.Resp) resp;}
与H5的JS交互：JS调用安卓：JsCallAndroid->getInvoice() {WXInvoiceUtils.getInvoice();}
安卓回传JS: WebView.evaluateJavascript(“javascript:window.PostWxInvoiceList(DATA)”, callBack);

1. 初始化IWXAPI

像支付一样，需要先初始化IWXAPI，定义全局变量 private IWXAPI wechat;

    public void initWechat(Activity context,String wxAppid) {
       if (null == wechat) {
            wechat = WXAPIFactory.createWXAPI(context.getApplicationContext(), wxAppid, true);
            boolean isSuccsee = wechat.registerApp(wxAppid);
            Log.e("initWechat","isSuccsee"+isSuccsee)
        }
    }

2. 发起获取发票请求

请求方法：IWXAPI.sendReq(ChooseCardFromWXCardPackage.Req );
ChooseCardFromWXCardPackage.Req 参数配置方法如下：

  /**
   * 发起获取发票请求
   */
  public static void getInvoice() {
        //时间戳
        String timeStamp = String.valueOf(System.currentTimeMillis() / 1000);
        ChooseCardFromWXCardPackage.Req req = new ChooseCardFromWXCardPackage.Req();
        //微信开发者账号appId
        req.appId = wxAppid;
        //类型：获取发票
        req.cardType = "INVOICE";
        //随机字符串
        req.nonceStr = timeStamp;
        //时间戳
        req.timeStamp = timeStamp;
        //签名类型SHA1
        req.signType = "SHA1";
        req.locationId = "";
        req.cardId = "";
        req.canMultiSelect = "1";
        //签名
        req.cardSign = createSign(req.appId, req.nonceStr, req.nonceStr, req.cardType);
        wechat.sendReq(req);
    }

3. 生成请求微信签名信息

利用SortedMap 保存并排序app_id，nonce_str，card_type，time_stamp等参数，然后进行SHA1加密。

    /**
     * 微信支付签名算法sign
     */
    private static String createSign(String appId, String nonceStr, String timestamp, String card_type) {
        SortedMap<Object, Object> parameters = new TreeMap<>();
        parameters.put("app_id", appId);
        parameters.put("nonce_str", nonceStr);
        parameters.put("card_type", timestamp);
        parameters.put("time_stamp", card_type);
        StringBuffer sb = new StringBuffer();
        Set es = parameters.entrySet();
        // 所有参与传参的参数按照accsii排序（升序）
        Iterator it = es.iterator();
        while (it.hasNext()) {
            @SuppressWarnings("rawtypes")
            Map.Entry entry = (Map.Entry) it.next();
            String k = (String) entry.getKey();
            Object v = entry.getValue();
            if (null != v && !"".equals(v) && !"sign".equals(k)
                    && !"key".equals(k)) {
                sb.append(k + "=" + v + "&");
            }
        }
        String sign = shaEncode(sb.toString()).toUpperCase();
        return sign;
    }

4. Java SHA1实现方法

/**
     * SHA1实现
     *
     * @author haojy
     * 2020年7月29日
     */
    public static String shaEncode(String inStr) {
        MessageDigest sha = null;
        try {
            sha = MessageDigest.getInstance("SHA");
        } catch (Exception e) {
            System.out.println(e.toString());
            e.printStackTrace();
            return "";
        }

        byte[] byteArray = new byte[0];
        try {
            byteArray = inStr.getBytes("UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        byte[] md5Bytes = sha.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();
        for (int i = 0; i < md5Bytes.length; i++) {
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16) {
                hexValue.append("0");
            }
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString();
    }

5. 接收返回数据

需要注意WXEntryActivity位置，需要放到app包名的Pageage下

public class WXEntryActivity extends Activity implements IWXAPIEventHandler {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        WechatManager.getInstance().getApi().handleIntent(getIntent(), this);
    }

    @Override
    public void onReq(BaseReq baseReq) {
    }

    //发送到微信请求的响应结果
    @Override
    public void onResp(BaseResp resp) {
       if (resp instanceof ChooseCardFromWXCardPackage.Resp) {
         ChooseCardFromWXCardPackage.Resp cardResp = (ChooseCardFromWXCardPackage.Resp) resp;
         SPUtils.getInstance().put("CardItemList", cardResp.cardItemList);
      }
      finish();
    }

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

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原文链接：https://blog.csdn.net/hjy258/article/details/109021271