Android中怎么实现微信支付功能，相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。
去微信开放平台申请微信支付服务，绑定自己的应用这里具体不多讲，但是一定要申请完成，将会得到是三个参数
//appid 微信分配的公众账号IDpublic static final String APP_ID = "";//商户号 微信分配的公众账号IDpublic static final String MCH_ID = "";// API密钥，在商户平台设置public static final String API_KEY= "";**坑点提示：在微信开发平台设置包名和签名。这里的包名一定要和你自己的包名一样，就是manifest中的package,签名一定要和你用官方app生成的一样(https://open.weixin.qq.com/zh_CN/htmledition/res/dev/download/sdk/Gen_Signature_Android.apk)。
微信会根据你的填写的包名，然后对你的keystore进行一种算法，生成你的签名。包名和签名一定要和微信开放平台的相同。不过这里需要注意的是，如果你发布的正式版本，需要用官方app重新生成签名，然后在开放平台重新设置sign，因为测试版本的keystore与正式版的keystore不一样。总之，就是你用的keystore生成的sign要和微信开放平台的时刻保持一致。**
准备工作做好了，接下来就是开发了，先下载微信的jar包，导入。
微信支付分为三个步骤
① .生成prepayId
@Overrideprotected Map<String, String> doInBackground(String... params) { // TODO Auto-generated method stub String url=String.format(params[0]); String entity=getProductArgs(); Log.e("Simon",">>>>"+entity); byte[] buf=Util.httpPost(url, entity); String content = new String(buf); Log.e("orion", "----"+content); Map<String,String> xml=decodeXml(content); return xml;}② .生成签名参数
private void genPayReq() { req.appId = Constants.APP_ID; req.partnerId = Constants.MCH_ID; if (resultunifiedorder!=null) { req.prepayId = resultunifiedorder.get("prepay_id"); req.packageValue = "prepay_id="+resultunifiedorder.get("prepay_id"); } else { Toast.makeText(MainActivity.this, "prepayid为空", Toast.LENGTH_SHORT).show(); } req.nonceStr = getNonceStr(); req.timeStamp = String.valueOf(genTimeStamp()); List<NameValuePair> signParams = new LinkedList<NameValuePair>(); signParams.add(new BasicNameValuePair("appid", req.appId)); signParams.add(new BasicNameValuePair("noncestr", req.nonceStr)); signParams.add(new BasicNameValuePair("package", req.packageValue)); signParams.add(new BasicNameValuePair("partnerid", req.partnerId)); signParams.add(new BasicNameValuePair("prepayid", req.prepayId)); signParams.add(new BasicNameValuePair("timestamp", req.timeStamp)); req.sign = genAppSign(signParams); sb.append("sign\n"+req.sign+"\n\n"); textView.setText(sb.toString()); Log.e("Simon", "----"+signParams.toString());}③ .调起支付
private void sendPayReq() { msgApi.registerApp(Constants.APP_ID); msgApi.sendReq(req); Log.i(">>>>>", req.partnerId);}下面给出完整代码
package com.alpha.live;import java.io.StringReader;import java.util.HashMap;import java.util.LinkedList;import java.util.List;import java.util.Map;import java.util.Random;import org.apache.http.NameValuePair;import org.apache.http.message.BasicNameValuePair;import org.xmlpull.v1.XmlPullParser;import com.tencent.mm.sdk.modelpay.PayReq;import com.tencent.mm.sdk.openapi.IWXAPI;import com.tencent.mm.sdk.openapi.WXAPIFactory;import android.app.Activity;import android.app.AlertDialog;import android.app.ProgressDialog;import android.os.AsyncTask;import android.os.Bundle;import android.util.Log;import android.util.Xml;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity implements OnClickListener { private Button submitButton; private Button confirmButton; private TextView textView; private StringBuffer sb; private Map<String,String> resultunifiedorder; private PayReq req; private final IWXAPI msgApi = WXAPIFactory.createWXAPI(this, null); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); submitButton=(Button) findViewById(R.id.bt_submit_order); confirmButton=(Button) findViewById(R.id.bt_corfirm); textView=(TextView) findViewById(R.id.tv_prepay_id); submitButton.setOnClickListener(this); confirmButton.setOnClickListener(this); sb=new StringBuffer(); req=new PayReq(); } @Override public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { case R.id.bt_submit_order: String urlString="https://api.mch.weixin.qq.com/pay/unifiedorder"; PrePayIdAsyncTask prePayIdAsyncTask=new PrePayIdAsyncTask(); prePayIdAsyncTask.execute(urlString); //生成prepayId break; case R.id.bt_corfirm: genPayReq();//生成签名参数 sendPayReq();//调起支付 break; default: break; } } private void sendPayReq() { msgApi.registerApp(Constants.APP_ID); msgApi.sendReq(req); Log.i(">>>>>", req.partnerId); } private long genTimeStamp() { return System.currentTimeMillis() / 1000; } private void genPayReq() { req.appId = Constants.APP_ID; req.partnerId = Constants.MCH_ID; if (resultunifiedorder!=null) { req.prepayId = resultunifiedorder.get("prepay_id"); req.packageValue = "prepay_id="+resultunifiedorder.get("prepay_id"); } else { Toast.makeText(MainActivity.this, "prepayid为空", Toast.LENGTH_SHORT).show(); } req.nonceStr = getNonceStr(); req.timeStamp = String.valueOf(genTimeStamp()); List<NameValuePair> signParams = new LinkedList<NameValuePair>(); signParams.add(new BasicNameValuePair("appid", req.appId)); signParams.add(new BasicNameValuePair("noncestr", req.nonceStr)); signParams.add(new BasicNameValuePair("package", req.packageValue)); signParams.add(new BasicNameValuePair("partnerid", req.partnerId)); signParams.add(new BasicNameValuePair("prepayid", req.prepayId)); signParams.add(new BasicNameValuePair("timestamp", req.timeStamp)); req.sign = genAppSign(signParams); sb.append("sign\n"+req.sign+"\n\n"); textView.setText(sb.toString()); Log.e("Simon", "----"+signParams.toString()); } private String genAppSign(List<NameValuePair> params) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < params.size(); i++) { sb.append(params.get(i).getName()); sb.append('='); sb.append(params.get(i).getValue()); sb.append('&'); } sb.append("key="); sb.append(Constants.API_KEY); this.sb.append("sign str\n"+sb.toString()+"\n\n"); String appSign = MD5.getMessageDigest(sb.toString().getBytes()); Log.e("Simon","----"+appSign); return appSign; } private class PrePayIdAsyncTask extends AsyncTask<String,Void, Map<String, String>> { private ProgressDialog dialog; @Override protected void onPreExecute() { // TODO Auto-generated method stub super.onPreExecute(); dialog = ProgressDialog.show(MainActivity.this, "提示", "正在提交订单"); } @Override protected Map<String, String> doInBackground(String... params) { // TODO Auto-generated method stub String url=String.format(params[0]); String entity=getProductArgs(); Log.e("Simon",">>>>"+entity); byte[] buf=Util.httpPost(url, entity); String content = new String(buf); Log.e("orion", "----"+content); Map<String,String> xml=decodeXml(content); return xml; } @Override protected void onPostExecute(Map<String, String> result) { // TODO Auto-generated method stub super.onPostExecute(result); if (dialog != null) { dialog.dismiss(); } sb.append("prepay_id\n"+result.get("prepay_id")+"\n\n"); textView.setText(sb.toString()); resultunifiedorder=result; } } public Map<String,String> decodeXml(String content) { try { Map<String, String> xml = new HashMap<String, String>(); XmlPullParser parser = Xml.newPullParser(); parser.setInput(new StringReader(content)); int event = parser.getEventType(); while (event != XmlPullParser.END_DOCUMENT) { String nodeName=parser.getName(); switch (event) { case XmlPullParser.START_DOCUMENT: break; case XmlPullParser.START_TAG: if("xml".equals(nodeName)==false){ //实例化student对象 xml.put(nodeName,parser.nextText()); } break; case XmlPullParser.END_TAG: break; } event = parser.next(); } return xml; } catch (Exception e) { Log.e("Simon","----"+e.toString()); } return null; } private String getProductArgs() { // TODO Auto-generated method stub StringBuffer xml=new StringBuffer(); try { String nonceStr=getNonceStr(); xml.append("<xml>"); List<NameValuePair> packageParams=new LinkedList<NameValuePair>(); packageParams.add(new BasicNameValuePair("appid",Constants.APP_ID)); packageParams.add(new BasicNameValuePair("body", "APP pay test")); packageParams.add(new BasicNameValuePair("mch_id", Constants.MCH_ID)); packageParams.add(new BasicNameValuePair("nonce_str", nonceStr)); packageParams.add(new BasicNameValuePair("notify_url", "https://www.baidu.com"));//写你们的回调地址 packageParams.add(new BasicNameValuePair("out_trade_no",genOutTradNo())); packageParams.add(new BasicNameValuePair("total_fee", "1")); packageParams.add(new BasicNameValuePair("trade_type", "APP")); String sign=getPackageSign(packageParams); packageParams.add(new BasicNameValuePair("sign", sign)); String xmlString=toXml(packageParams); return xmlString; } catch (Exception e) { // TODO: handle exception return null; } } //生成订单号,测试用，在客户端生成 private String genOutTradNo() { Random random = new Random();// return "dasgfsdg1234"; //订单号写死的话只能支付一次，第二次不能生成订单 return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes()); } //生成随机号，防重发 private String getNonceStr() { // TODO Auto-generated method stub Random random=new Random(); return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes()); } private String getPackageSign(List<NameValuePair> params) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < params.size(); i++) { sb.append(params.get(i).getName()); sb.append('='); sb.append(params.get(i).getValue()); sb.append('&'); } sb.append("key="); sb.append(Constants.API_KEY); String packageSign = MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase(); Log.e("Simon",">>>>"+packageSign); return packageSign; } private String toXml(List<NameValuePair> params) { StringBuilder sb = new StringBuilder(); sb.append("<xml>"); for (int i = 0; i < params.size(); i++) { sb.append("<"+params.get(i).getName()+">"); sb.append(params.get(i).getValue()); sb.append("</"+params.get(i).getName()+">"); } sb.append("</xml>"); Log.e("Simon",">>>>"+sb.toString()); return sb.toString(); }}看完上述内容，你们掌握Android中怎么实现微信支付功能的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注编程网行业资讯频道，感谢各位的阅读！
