微信打赏的ID怎么生成的

[Gensun]

NSString *rewardStr = @"m0#tYKR_$YKjkz~7IjWLFL";
NSData *rewardData = [rewardStr dataUsingEncoding:4];  
[qrCodeScanner notifyResult:rewardStr type:@"WX_CODE" version:0 rawData:rewardData];