When I attempt to update my table **UITableview** using the code below my cells become smaller. I was wondering if anyone has faced the same problem and would know why this is happening.
NSMutableArray* indexPaths = [[NSMutableArray alloc] init];
for (int i = 20; i < 20 + 20; i++) {
[indexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
}
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:(UITableViewRowAnimationBottom)];
[self.tableView endUpdates];
....
#CreativityKills.
if your auto layout is on please try following method to add after add rows. It may help you if it was a problem of auto-layout.
NSMutableArray* indexPaths = [[NSMutableArray alloc] init];
for (int i = 20; i < 20 + 20; i++) {
[indexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
}
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:(UITableViewRowAnimationBottom)];
[self.tableView endUpdates];
[self adjustHeightOfTableview];
- (void)adjustHeightOfTableview
{
CGFloat height = self.tableView.contentSize.height;
CGFloat maxHeight = self.tableView.superview.frame.size.height - self.tableView.frame.origin.y;
// if the height of the content is greater than the maxHeight of
// total space on the screen, limit the height to the size of the
// superview.
if (height > maxHeight)
height = maxHeight;
// now set the height constraint accordingly
[UIView animateWithDuration:0.25 animations:^{
self.tableViewHeightConstraint.constant = height;
[self.view setNeedsUpdateConstraints];
}];
}
Hope this may help you.
May be you have not given implementation for UITableViewDelegate method:
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat
{
return 44.0;//your default row height
}
Related
I'm using insertRowsAtIndexPaths:withRowAnimation, and setting with UITableViewRowAnimationNone. Then i use the the mehod below
Insert UITableView row without ANY animation
But it causes a flash when reload the tableview. How can i fix the flash?
Thank you。
My demo is want to pull to load more local data and show on the tableview，but the last position is previous contentOffset.So i overwrite the UITableView's setContentSize function.
- (void)setContentSize:(CGSize)contentSize {
if (!CGSizeEqualToSize(self.contentSize, CGSizeZero)) {
if (contentSize.height> self.contentSize.height) {
CGPoint offset = self.contentOffset;
offset.y += contentSize.height - self.contentSize.height;
self.contentOffset = offset;
}
}
[super setContentSize:contentSize];
}
When pull to refresh, load the data and refresh tableview:
for (long j = 0; j < result.count; j++) {
NSIndexPath *index = [NSIndexPath indexPathForRow:j inSection:0];
[array addObject:index];
}
[UIView performWithoutAnimation:^{
[_mainTableView beginUpdates];
[_mainTableView insertRowsAtIndexPaths:array withRowAnimation:UITableViewRowAnimationNone];
[_mainTableView endUpdates];
}];
I want to add cells at the bottom of a UITableView, and scroll to make it fully visible (just like in Whatsapp when you send or receive a message).
I've tried doing this:
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForItem:[self.tableView numberOfRowsInSection:0]-1 inSection:0] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
But this makes a graphical glitch and the table flashes and make a bad scrolling instead of a smooth one.
Any help with this?
here what I have done is, inserted a row and then changed the content inset of the tableView
-(IBOutlet)sendButton:(id)sender
{
[array addObject:textView.text];
[self addAnotherRow];
}
- (void)addAnotherRow {
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:(array.count - 1) inSection:0];
[self.messagesTableView beginUpdates];
[self.messagesTableView insertRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[self.messagesTableView endUpdates];
[self updateContentInsetForTableView:self.messagesTableView animated:YES];
// TODO: if the scroll offset was at the bottom it can be scrolled down (allow user to scroll up and not override them)
[self.messagesTableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
- (void)updateContentInsetForTableView:(UITableView *)tableView animated:(BOOL)animated {
NSUInteger lastRow = [self tableView:tableView numberOfRowsInSection:0];
NSLog(#"last row: %lu", (unsigned long)lastRow);
NSLog(#"items count: %lu", (unsigned long)array.count);
NSUInteger lastIndex = lastRow > 0 ? lastRow - 1 : 0;
NSIndexPath *lastIndexPath = [NSIndexPath indexPathForItem:lastIndex inSection:0];
CGRect lastCellFrame = [self.messagesTableView rectForRowAtIndexPath:lastIndexPath];
// top inset = table view height - top position of last cell - last cell height
CGFloat topInset = MAX(CGRectGetHeight(self.messagesTableView.frame) - lastCellFrame.origin.y - CGRectGetHeight(lastCellFrame), 0);
// What about this way? (Did not work when tested)
// CGFloat topInset = MAX(CGRectGetHeight(self.tableView.frame) - self.tableView.contentSize.height, 0);
NSLog(#"top inset: %f", topInset);
UIEdgeInsets contentInset = tableView.contentInset;
contentInset.top = topInset;
NSLog(#"inset: %f, %f : %f, %f", contentInset.top, contentInset.bottom, contentInset.left, contentInset.right);
NSLog(#"table height: %f", CGRectGetHeight(self.messagesTableView.frame));
UIViewAnimationOptions options = UIViewAnimationOptionBeginFromCurrentState;
[UIView animateWithDuration:animated ? 0.25 : 0.0 delay:0.0 options:options animations:^{
tableView.contentInset = contentInset;
} completion:^(BOOL finished) {
}];
}
Note: to view existing messages from array, you have to include this
also.
- (void)viewDidLayoutSubviews {
[self updateContentInsetForTableView:self.messagesTableView animated:NO];
}
example function to add an item:
- (IBAction)addItem:(UIBarButtonItem *)sender {
[self.items addObject:[NSString stringWithFormat:#"Item %lu", self.items.count + 1]];
NSIndexPath *indexPathToInsert = [NSIndexPath indexPathForRow:self.items.count - 1 inSection:0];
[self.tableView insertRowsAtIndexPaths:#[indexPathToInsert] withRowAnimation:UITableViewRowAnimationAutomatic];
[self.tableView scrollToRowAtIndexPath:indexPathToInsert atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
for me the animation looks perfectly fine this way!
Well, what I did is use [self.tableView scrollToRowAtIndexPath... but calling it from a 0.1s NSTimer.
Make insertions animated and after endUpdates scroll bottom not animating. Worked for me
Swift
self.tableView.beginUpdates()
self.tableView.insertRowsAtIndexPaths(newIndexPaths, withRowAnimation: UITableViewRowAnimation.Top)
self.tableView.endUpdates()
self.tableView.scrollToRowAtIndexPath(NSIndexPath(forRow: self.tableDataCount-1, inSection: 0), atScrollPosition: .Bottom, animated: false)
I want to add rows to a tableview with begin/endUpdates to prevent the jump of the tableview when i do reloadData
this is my code
- (void)updateTableWithNewRowCount:(NSInteger)rowCount
andNewData:(NSArray *)newData {
// Save the tableview content offset
CGPoint tableViewOffset = [self.messagesTableView contentOffset];
// Turn of animations for the update block
// to get the effect of adding rows on top of TableView
[UIView setAnimationsEnabled:NO];
[self.messagesTableView beginUpdates];
NSMutableArray *rowsInsertIndexPath = [[NSMutableArray alloc] init];
int heightForNewRows = 0;
for (NSInteger i = 0; i < rowCount; i++) {
NSIndexPath *tempIndexPath = [NSIndexPath indexPathForRow:i inSection:0];
[rowsInsertIndexPath addObject:tempIndexPath];
// [self.messages insertObject:[newData objectAtIndex:i] atIndex:i];
[self addMessage:[newData objectAtIndex:i]];
heightForNewRows =
heightForNewRows + [self heightForCellAtIndexPath:tempIndexPath];
}
[self.messagesTableView insertRowsAtIndexPaths:rowsInsertIndexPath
withRowAnimation:UITableViewRowAnimationNone];
tableViewOffset.y += heightForNewRows;
[self.messagesTableView endUpdates];
[UIView setAnimationsEnabled:YES];
[self.messagesTableView setContentOffset:tableViewOffset animated:NO];
}
And sometimes (not everytime) I get this error
invalid number of rows in section 0.
The number of rows contained in an existing section after
the update (2) must be equal to the number of rows contained in that section
before the update (2), plus or minus the number of rows inserted or deleted
from that section (2 inserted, 0 deleted) and plus or minus the number of
rows moved into or out of that section (0 moved in, 0 moved out).
How do i prevent this error ?
if you dont want animation then use directly
- (void)updateTableWithNewRowCount:(NSInteger)rowCount
andNewData:(NSArray *)newData {
// Save the tableview content offset
CGPoint tableViewOffset = [self.messagesTableView contentOffset];
// Turn of animations for the update block
// to get the effect of adding rows on top of TableView
NSMutableArray *rowsInsertIndexPath = [[NSMutableArray alloc] init];
int heightForNewRows = 0;
for (NSInteger i = 0; i < rowCount; i++) {
NSIndexPath *tempIndexPath = [NSIndexPath indexPathForRow:i inSection:0];
[rowsInsertIndexPath addObject:tempIndexPath];
// [self.messages insertObject:[newData objectAtIndex:i] atIndex:i];
[self addMessage:[newData objectAtIndex:i]];
heightForNewRows =
heightForNewRows + [self heightForCellAtIndexPath:tempIndexPath];
}
tableViewOffset.y += heightForNewRows;
[self.messagesTableView reloadData];
[self.messagesTableView setContentOffset:tableViewOffset animated:NO];
}
If you want to quickly jump to a selected indexPath (with or without animation), you can use this function:
//My function to populate
//tableView is synthesized
-(void)setNewMessage:(NSString*)message{
// ...
NSIndexPath *selectedIndexPath = [tableView indexPathForSelectedRow];
// if your selectedIndexPath==nil, the table scroll stay in the same position
[self reloadData:selectedIndexPath animated:NO];
}
//My reload data wrapper
-(void)reloadData:(NSIndexPath *)selectedIndexPath animated:(BOOL)animated{
[tableView reloadData];
// atScrollPosition can receive different parameters (eg:UITableViewScrollPositionMiddle)
[tableView scrollToRowAtIndexPath:selectedIndexPath
atScrollPosition:UITableViewScrollPositionTop
animated:animated];
}
Once I needed that same flexibility in a tableView and this function has met my needs. You don`t need the "setAnimationsEnabled", just use:
[tableView scrollToRowAtIndexPath:nil
atScrollPosition:UITableViewScrollPositionNone
animated:NO];
];
I hope it helped.
Try this, I am not sure whether this will work or not.
- (void)updateTableWithNewRowCount:(NSInteger)rowCount
andNewData:(NSArray *)newData {
// Save the tableview content offset
CGPoint tableViewOffset = [self.messagesTableView contentOffset];
// Turn of animations for the update block
// to get the effect of adding rows on top of TableView
[UIView setAnimationsEnabled:NO];
NSMutableArray *rowsInsertIndexPath = [[NSMutableArray alloc] init];
int heightForNewRows = 0;
for (NSInteger i = 0; i < rowCount; i++) {
NSIndexPath *tempIndexPath = [NSIndexPath indexPathForRow:i inSection:0];
[rowsInsertIndexPath addObject:tempIndexPath];
// [self.messages insertObject:[newData objectAtIndex:i] atIndex:i];
[self addMessage:[newData objectAtIndex:i]];
heightForNewRows = heightForNewRows + [self heightForCellAtIndexPath:tempIndexPath];
}
tableViewOffset.y += heightForNewRows;
[UIView setAnimationsEnabled:YES];
[self.messagesTableView setContentOffset:tableViewOffset animated:NO];
double delayInSeconds = 1.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[self.messagesTableView beginUpdates];
[self.messagesTableView insertRowsAtIndexPaths:rowsInsertIndexPath
withRowAnimation:UITableViewRowAnimationNone];
[self.messagesTableView endUpdates];
});
}
Note: You might require to update rowsInsertIndexPath reference to use inside the block (__block type).
I am trying to figure out a way to animate the deletion of a UICollectionViewCell similarly to springboard in iOS 7. The deleted cell should shrink into nothingness and the remaining cells should slide over to fill its place (the sliding is the important part). I have tried:
• Setting the frame of each cell to the frame of the previous cell, like so:
UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:[NSIndexPath indexPathForItem:i inSection:0]];
CGRect rect = [self.collectionView cellForItemAtIndexPath:[NSIndexPath indexPathForItem:i - 1 inSection:0]].frame;
[UIView animateWithDuration:0.2 animations:^{
cell.frame = rect;
}];
But this did not work, as the cells did not move at all.
• Both of the following:
[self.collectionView performBatchUpdates:^{
[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];
} completion:nil];
and
[UIView animateWithDuration:0.2 animations:^{
[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];
}];
But these make the cells crossfade to their required spots, not slide.
I also found this project, which uses the following:
for (int i = index+1; i<[items count]; i++) {
SEMenuItem *item = [items objectAtIndex:i];
[UIView animateWithDuration:0.2 animations:^{
if (i < index + remainingNumberOfItemsInPage) {
int intVal = item.frame.origin.x;
if (intVal %3== 0)
[item setFrame:CGRectMake(item.frame.origin.x+2*item.frame.size.width, item.frame.origin.y-item.frame.size.height-5, item.frame.size.width, item.frame.size.height)];
else
[item setFrame:CGRectMake(item.frame.origin.x-item.frame.size.width, item.frame.origin.y, item.frame.size.width, item.frame.size.height)];
}
[item updateTag:item.tag-1];
}];
}
However, it is not in a UICollectionView, so it does not help me.
Note: I am doing this on an iPad, just in case it matters to you.
Any ideas?
Subclass UICollectionViewFlowLayout. Implement:
- (UICollectionViewLayoutAttributes *)finalLayoutAttributesForDisappearingItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewLayoutAttributes *attr = [self layoutAttributesForItemAtIndexPath:indexPath]; // might need to replace self with super
attr.transform = CGAffineTransformMakeScale(0, 0);
return attr;
}
In addition to duci9y's answer, (using attr.transform = CGAffineTransformMakeScale(0,0);), the following makes the tiles slide. I can't believe I didn't think of this before.
[self.collectionView performBatchUpdates:^{
[self.collectionView deleteItemsAtIndexPaths:#[indexPath]];
[dataSource removeObjectAtIndex:indexPath.row];
} completion:nil];
I have a table view (without scrolling) inside a UIPopoverController which has 4 cells. And sometimes it needs to have an extra cell (1 max). If I am animating the adding and subtracting of that cell, can I update the popover's height as well?
Here is how I create the popover table view:
- (void)createPopoverTable
{
//set up array
_arrayList = [NSMutableArray arrayWithObjects:#"one", #"two", #"three", #"four", nil];
//Make row selections persist.
self.clearsSelectionOnViewWillAppear = NO;
//View height
NSInteger rowsCount = [_arrayList count];
NSInteger singleRowHeight = [self.tableView.delegate tableView:self.tableView heightForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
NSInteger totalRowsHeight = (rowsCount * singleRowHeight) + 20;
//View width
CGFloat largestLabelWidth = 0;
for (NSString *item in _arrayList) {
//check size of font using default label
CGSize labelSize = [item sizeWithFont:[UIFont boldSystemFontOfSize:20.0f]];
if (labelSize.width > largestLabelWidth) {
largestLabelWidth = labelSize.width;
}
}
//some padding for the width
CGFloat popoverWidth = largestLabelWidth + 200;
//Tell popover the size
self.contentSizeForViewInPopover = CGSizeMake(popoverWidth, totalRowsHeight);
}
Then in one of my methods I have this code for when the table needs to change:
[self.tableView beginUpdates];
//update the array
[_arrayList insertObject:#"Blue" atIndex:3];
//insert the row
[self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:3 inSection:0]] withRowAnimation:UITableViewRowAnimationTop];
[self.tableView endUpdates];
The code all "works" fine but when I add the extra cell, it is being cut off due to the non scrolling nature of my popover controller. Any way I can update that?
try this one it worked for me
-(void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
self.contentSizeForViewInPopover = self.tableView.contentSize;
}
-(void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[self.popoverControllerContainer setPopoverContentSize:self.contentSizeForViewInPopover animated:YES];
}