OC可变参数的参数传递

+ (void)logWithFormat:(NSString *)format, ... {
    va_list paramList;
    va_start(paramList,format);
    NSString* log = [[NSString alloc]initWithFormat:format arguments:paramList];
    NSString* logToStore = [log stringByAppendingString:@"\n"];
    va_end(paramList);
    
    NSString* logPath = [[self cacheDirectory] stringByAppendingPathComponent:LogFileName];
    BOOL writeResult = [self appendStringUsingFileHandle:logToStore toPath:logPath];
    if (writeResult) {
        NSLog(@"%@",log);
    }else {
        NSLog(@"写入失败：%@",log);
    }
}