-(NSString )createMD5SingForPay:(NSString )appid_key partnerid:(NSString)partnerid_key prepayid:(NSString )prepayid_key package:(NSString )package_key noncestr:(NSString)noncestr_key timestamp:(UInt32)timestamp_key 
{ 
NSMutableDictionary *signParams = [NSMutableDictionary dictionary]; 
[signParams setObject:appid_key forKey:@”appid”]; 
[signParams setObject:noncestr_key forKey:@”noncestr”]; 
[signParams setObject:package_key forKey:@”package”]; 
[signParams setObject:partnerid_key forKey:@”partnerid”]; 
[signParams setObject:prepayid_key forKey:@”prepayid”]; 
[signParams setObject:[NSString stringWithFormat:@”%u”,(unsigned int)timestamp_key] forKey:@”timestamp”];
NSMutableString *contentString =[NSMutableString string]; 
NSArray *keys = [signParams allKeys]; 
//按字母順序排序 
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 ( ![[signParams objectForKey:categoryId] isEqualToString:@”“] 
&& ![[signParams objectForKey:categoryId] isEqualToString:@”sign”] 
&& ![[signParams objectForKey:categoryId] isEqualToString:@”key”] 
) 
{ 
[contentString appendFormat:@”%@=%@&”, categoryId, [signParams objectForKey:categoryId]];
} 
} 
//添加商戶密鑰key字段 
[contentString appendFormat:@”key=%@”, @”這里填寫商戶密鑰”]; 
NSString *result = [self md5:contentString]; 
return result;

}//創(chuàng)建發(fā)起支付時的sige簽名

-(NSString ) md5:(NSString )str 
{ 
const char *cStr = [str UTF8String]; 
unsigned char result[16]= “0123456789abcdef”; 
CC_MD5(cStr, (CC_LONG)strlen(cStr), result); 
//這里的x是小寫則產(chǎn)生的md5也是小寫，x是大寫則md5是大寫，這里只能用大寫，微信的大小寫驗證很逗 
return [NSString stringWithFormat: 
@”%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X”, 
result[0], result[1], result[2], result[3], 
result[4], result[5], result[6], result[7], 
result[8], result[9], result[10], result[11], 
result[12], result[13], result[14], result[15] 
]; 
}//MD5 加密