NSdate 与 NSString转换

1. date类型转换为字符串，格式可以在这个格式字符串中自定义，例如加上时分秒

   -(NSString*)nsdateToString:(NSDate *)date
   {
   NSDateFormatter *dateFormat=[[NSDateFormatter alloc]init];
   [dateFormat setDateFormat:@"yyyy-MM-dd"];
   NSString* string=[dateFormat stringFromDate:date];
   NSLog(@"%@",string);
   return string;
   }
   

2. 字符串类型转换为NSDate

   - (NSDate *)dateFromString:(NSString *)dateString
    {
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat: @"yyyy-MM-dd"];
    NSDate *destDate= [dateFormatter dateFromString:dateString];
    return destDate;
    }