数据转换

//字典转字符串

+(NSString *)stringWithDict:(NSDictionary *)dict

{

NSError *parseError = nil;

NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:&parseError];

if (parseError) {

NSLog(@"stringWithDict: /n%@",parseError);

}

return [[NSString alloc]initWithData:jsonData encoding:NSUTF8StringEncoding];

}

---

//字符串转字典

+(NSDictionary *)dictWithString:(NSString *)string

{

NSData *data=[string dataUsingEncoding:NSUTF8StringEncoding];

NSError *error;

NSDictionary *dict=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error];

if (error) {

NSLog(@"dictWithString:　/n%@",error);

}

return dict;

}

---

//字符串转日期

+(NSDate *)dateWithString:(NSString *)string timeStringFormat:(NSString *)format

{

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

[formatter setDateFormat:NSLocalizedString(format,nil)];

NSDate *date = [formatter dateFromString:string];

return date;

}

---

//日期转字符串

+(NSString *)stringWithDate:(NSDate *)date timeStringFormat:(NSString *)format

{

NSDateFormatter *formatter=[[NSDateFormatter alloc]init];

[formatter setDateFormat:NSLocalizedString(format,nil)];

NSString *nowDate=[formatter stringFromDate:date];

return nowDate;

}

---

//计算某个时间到目前时间差(XX 分钟/小时/天 前，)

+(int)numberOfTimeFromTodayByTime:(NSDate *)time timeType:(time_type)timetype

{

NSTimeInterval old=[time timeIntervalSince1970];

NSDate *nowDate=[NSDate dateWithTimeIntervalSinceNow:0];

NSTimeInterval now=[nowDate timeIntervalSince1970]*1;

NSTimeInterval cha=now-old;

NSString *timeString=@"";

if (timetype==minute) {

timeString=[NSString stringWithFormat:@"%f",cha/60];

}

if (timetype==hour) {

timeString=[NSString stringWithFormat:@"%f",cha/3600];

}

if (timetype==day) {

timeString=[NSString stringWithFormat:@"%f",cha/86400];

}

timeString=[timeString substringToIndex:timeString.length-7];

return timeString.intValue;

}