[英]UITableView scroll to section that is closest to todays date
我有一個tableview
,里面有日程表。 每一天都是一個單獨的section
。 你可以在這看到我的意思
現在我希望tableview
滾動到今天的section
,或者如果今天沒有section
到最近的section
。
我知道我應該使用以下代碼:
[tableView scrollToRowAtIndexPath:scrollIndexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
現在我有一個NSMutableDictionary
包含我的排序約會/天。 你可以看到下面的功能:
-(NSDictionary *)sortKalendar:(NSMutableArray *)appointments{
NSMutableDictionary *buffer = [[NSMutableDictionary alloc] init];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd-MM-yyyy"];
for (int i = 0; i < appointments.count; i++) {
Appointment *object = [appointments objectAtIndex:i];
NSString *date = [formatter stringFromDate:object.app_start];
if(!(date == NULL) ){
NSLog(@"date is %@",date);
if ([buffer objectForKey:date]) {
[(NSMutableArray *)[buffer objectForKey:date] addObject:object];
} else {
NSMutableArray *mutableArray = [[NSMutableArray alloc] initWithObjects:object, nil];
[buffer setObject:mutableArray forKey:date];
}
}
}
NSDictionary *result = [NSDictionary dictionaryWithDictionary:buffer];
return result;
}
我的問題是,如何找到正確的NSIndexpath
?
提前致謝 !
編輯
目前我正在使用以下內容。 但有些事情仍然不對。
NSArray *keys = [dictAppointments allKeys];
NSLog(@"KEYS ARE %@",keys) ;
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd-MM-yyyy"];
NSArray *sortedArray = [keys sortedArrayUsingComparator:^(id obj1, id obj2) {
NSDate *date1 = [formatter dateFromString:obj1];
NSDate *date2 = [formatter dateFromString:obj2];
NSNumber *interval1 = [NSNumber numberWithDouble:[date1 timeIntervalSinceNow]];
NSNumber *interval2 = [NSNumber numberWithDouble:[date2 timeIntervalSinceNow]];
return (NSComparisonResult)[interval1 compare:interval2];
}];
NSLog(@"Sorted Array %@",sortedArray);
NSString *closestDateString = [sortedArray objectAtIndex:0];
NSLog(@"Closest date string is %@",closestDateString);
int section = [keys indexOfObject:closestDateString];
NSIndexPath *scrollIndexPath = [NSIndexPath indexPathForRow:0 inSection:section];
[tableView scrollToRowAtIndexPath:scrollIndexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
這給了我以下日志:
2014-01-07 13:28:42.420 Adsolut[9579:60b] KEYS ARE (
"03-12-2013",
"20-12-2013",
"17-12-2013",
"05-01-2014",
"21-12-2013",
"31-12-2013",
"04-01-2014",
"06-01-2014",
"16-01-2014",
"29-12-2013",
"03-01-2014",
"11-01-2014",
"18-12-2013",
"31-01-2014"
)
2014-01-07 13:28:42.437 Adsolut[9579:60b] Sorted Array (
"03-12-2013",
"17-12-2013",
"18-12-2013",
"20-12-2013",
"21-12-2013",
"29-12-2013",
"31-12-2013",
"03-01-2014",
"04-01-2014",
"05-01-2014",
"06-01-2014",
"11-01-2014",
"16-01-2014",
"31-01-2014"
)
您可以使用約會日期和當前日期之間的時間間隔對數組進行排序,
NSArray *keys = [yourDictionary allKeys];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd-MM-yyyy"];
NSArray *sortedArray = [keys sortedArrayUsingComparator:^(id obj1, id obj2) {
NSDate *date1 = [formatter dateFromString:obj1];
NSDate *date2 = [formatter dateFromString:obj2];
NSNumber *interval1 = [NSNumber numberWithDouble:abs([date1 timeIntervalSinceNow])];
NSNumber *interval2 = [NSNumber numberWithDouble:abs([date2 timeIntervalSinceNow])];
return (NSComparisonResult)[interval1 compare:interval2];
}];
最近的日期,
NSString *closestDateString = [sortedArray objectAtIndex:0];
從那以后
int section = [keys indexOfObject:closestDateString];
NSIndexPath *scrollIndexPath = [NSIndexPath indexPathForRow:0 inSection:section];
你有一個排序日期數組,不是嗎? 我們把它說成dateArray
。
今天獲取日期對象: NSDate * today = [NSDate date];
搜索dateArray到最近的日期,獲取最近日期的索引。
NSDate * today = [NSDate date] ;
__block NSUInteger section = NSNotFound ;
__block NSTimeInterval timeInterval = NSTimeIntervalSince1970 ;
[dateArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSDate * date = obj ;
NSTimeInterval ti = [today timeIntervalSinceDate:date] ;
if (ti < 0)
ti = -ti ;
if (ti <= timeInterval) {
section = idx ;
timeInterval = ti ;
} else {
*stop = YES ;
}
}] ;
你現在知道了段索引,讓我們把它稱為sectionIndex
,該段中的第一行索引是0。
所以NSIndexPath是[NSIndexPath indexPathForRow:0 inSection:sectionIndex]
獲取日期列表(從您的字典或已有的字典)。 解決。 循環遍歷它( indexOfObjectPassingTest:
以查找日期>=
今天(或使用謂詞進行過濾,然后從結果中獲取第一項並獲取索引)。
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