实用技术——支付_微信

与微信官方签署在线协议

导入微信支付需要的SDK相关文件

配置App跳转的白名单

添加URL Schemes

配置代码

1. 在AppDelegate.m中向微信注册第三方应用
   //向微信终端程序注册第三方应用
   [WXApi registerApp:wexinAppId];
2. 确保支付结果回调方法能够接受到，在AppDelegate.m中添加一下代码
   - (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation{
   if([url.host isEqualToString:@"pay"]){
   return [WXApi handleOpenURL:url delegate:[WXApiManager sharedManager]];
   }else{
   return YES;
   }
   }
   - (BOOL)application:(UIApplication *)application handleOpenURL:(nonnull NSURL *)url
   {
   if([url.host isEqualToString:@"pay"]){
   return [WXApi handleOpenURL:url delegate:[WXApiManager sharedManager]];
   }else{
   return YES;
   }
   }
   - (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<NSString *,id> *)options{
   if([url.host isEqualToString:@"pay"]){
   return [WXApi handleOpenURL:url delegate:[WXApiManager sharedManager]];
   }else{
   return YES;
   }
   }

• 设置支付信息，调用微信支付
  NSMutableDictionary dict = [result[@"data"] objectAtIndex:0];
  //调起微信支付
  PayReq req = [[PayReq alloc] init];
  //由用户微信号和AppID组成的唯一标识
  req.openID = [dict objectForKey:@"appid"];
  //商家向财付通申请的商家id
  req.partnerId = [dict objectForKey:@"mch_id"];
  //预支付订单
  req.prepayId = [dict objectForKey:@"prepay_id"];
  //随机串，防重发
  req.nonceStr = [dict objectForKey:@"nonce_str"];
  //时间戳，防重发
  req.timeStamp = [[dict objectForKey:@"timeStamp"] intValue];
  //商家根据财付通文档填写的数据和签名
  req.package = @"Sign=WXPay";
  //商家根据微信开放平台文档对数据做的签名
  req.sign = [self getWeiXinPaySign:req];
  [WXApi sendReq:req];

• 处理支付结果
  为了对支付结果可以进行不同的操作处理，可以创建一个单例对象来管理。
  #import <Foundation/Foundation.h>
  #import "WXApi.h"
  @protocol WXApiManagerDelegate <NSObject>
  @optional
  - (void)managerDidRecvPayForSuccessResponse:(PayResp *)response;

  - (void)managerDidRecvPayForFailResponse:(PayResp *)response;
  @end
  
  @interface WXApiManager : NSObject<WXApiDelegate>
  @property (nonatomic, assign) id<WXApiManagerDelegate> delegate;
  + (instancetype)sharedManager;
  @end
  
  #import "WXApiManager.h"
  @implementation WXApiManager
  
  #pragma mark - LifeCycle
  +(instancetype)sharedManager {
    static dispatch_once_t onceToken;
    static WXApiManager *instance;
    dispatch_once(&onceToken, ^{
    instance = [[WXApiManager alloc] init];
    });
  return instance;
  }
  
  - (void)dealloc {
    self.delegate = nil;
    [super dealloc];
  }
  
  #pragma mark - WXApiDelegate
  - (void)onResp:(BaseResp *)resp {
      if([resp isKindOfClass:[PayResp class]]){
          switch (resp.errCode) {
              case WXSuccess:
              {
                  if (_delegate && [_delegate respondsToSelector:@selector(managerDidRecvPayForSuccessResponse:)]) {
                  PayResp *payResp = (PayResp *)resp;
                  [_delegate managerDidRecvPayForSuccessResponse:payResp];
          }
      }
          break;
          
      default:
          if (_delegate && [_delegate respondsToSelector:@selector(managerDidRecvPayForFailResponse:)]) {
              PayResp *payResp = (PayResp *)resp;
              [_delegate managerDidRecvPayForFailResponse:payResp];
          }
          break;
      }
    }
  }
  @end
  

• 签名sign生成方法
  //获取微信签名
  -(NSString)getWeiXinPaySign:(PayReq)req
  {
  NSMutableDictionary *signParams = [NSMutableDictionary dictionary];
  [signParams setObject: req.openID forKey:@"appid"];
  [signParams setObject: req.nonceStr forKey:@"noncestr"];
  [signParams setObject: req.package forKey:@"package"];
  [signParams setObject: req.partnerId forKey:@"partnerid"];
  [signParams setObject: [NSString stringWithFormat:@"%u",(unsigned int)req.timeStamp] forKey:@"timestamp"];
  [signParams setObject: req.prepayId forKey:@"prepayid"];
  //生成签名
  NSString *sign = [self createMd5Sign:signParams];
  return sign;
  }

  //创建package签名
  -(NSString*) createMd5Sign:(NSMutableDictionary*)dict
  {
      NSMutableString *contentString  =[NSMutableString string];
      NSArray *keys = [dict allKeys];
      //按字母顺序排序
      NSArray *sortedArray = [keys sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
          return [obj1 compare:obj2 options:NSNumericSearch];
      }];
      //拼接字符串
      for (NSString *categoryId in sortedArray) {
          if (![[dict objectForKey:categoryId] isEqualToString:@""] &&
              ![categoryId isEqualToString:@"sign"] &&
              ![categoryId isEqualToString:@"key"]){
          
              [contentString appendFormat:@"%@=%@&", categoryId, [dict objectForKey:categoryId]];
             }
          }
      //添加key字段,商户密钥
      [contentString appendFormat:@"key=%@", @"xxxxxxxxxxx"];
      //得到MD5 sign签名
      NSString *md5Sign =[WXUtil md5:contentString];
      return md5Sign;
    }
  //md5 encode
  +(NSString *) md5:(NSString *)str
  {
      const char *cStr = [str UTF8String];
      unsigned char digest[CC_MD5_DIGEST_LENGTH];
      CC_MD5( cStr, (unsigned int)strlen(cStr), digest );
  
      NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
      //这里的x是小写则产生的md5也是小写，是大写则产生的md5是大写
      for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)
          [output appendFormat:@"%02X", digest[i]];
  
      return output;
  }
  

注意事项：

1. 签名Sign一定得进行MD5加密，格式严格按照微信官方方式加密。
   prepayId（预支付订单）失效、过期。
   如果出现上述问题（一般是参数错误），就会造成调起微信支付，只出现一个确定按钮

• 支付结果无法获取回调？
  确保第四步的b步骤是否实现
• 如果APP里面使用了友盟或者ShareSDK做分享，那就不用再导入SDK了，否则会出现一些诡异的问题，
  例如无法调起手机微信客户端、无法调起微信客户端web页面，调起了但是一闪而过。这都基本上都是因为分享的SDK里面已经包括了微信的SDK。所以如果出现诡异的错误了看看是不是两个冲突了。
• 如果你用了友盟社会化分享来做微信登录的话，那么你要先用友盟注册微信，后调用微信SDK注册
  [UMSocialWechatHandlersetWXAppId:SHappSecret:SH url:SHAREURL]；
  [WXApiregisterApp:SHARE_WX withDescription:@"demo"];
• 微信无法调起
  未安装微信、未将微信加入白名单