UITableviewCell subview appears only on scrolling or cell reuse (iOS) - ios

As in the image below, the UITableView subview appears only on tableview reload or cell reuse (during scrolling, mostly). The blue color circle is what I want in my UITableViewCell. When it first appears, it will be a small dot as you can see in the picture, and on scrolling or refreshing the tableview, it appears as the full circle.
What can be the issue?
I use the following code in cellforRowAtIndexPath method
cell.categoryRoundBackground.layer.cornerRadius=cell.categoryRoundBackground.frame.size.height/2;

try using dequeueReusableCellWithIdentifier: forIndexPath:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
CustomTableViewCell *cell1 = (CustomTableViewCell *)[tableView dequeueReusableCellWithIdentifier:#"CustomID" forIndexPath:indexPath];

The most likely problem is that at the moment when you access your cell's frame height the first time by calling
cell.categoryRoundBackground.frame.size.height / 2
the cell has never been placed in a table view, it has no idea what its frame height is going to be, and so it uses some default value. The actual height depends on the value returned by your code in heightForRowAtIndexPath: method.
You can work around this problem by computing the frame size yourself. You should be able to do that, because your code supplies the value to heightForRowAtIndexPath:.

It's possible that you change the corner radius before that the view layouts its subviews.
You should try to put the line
cell.categoryRoundBackground.layer.cornerRadius=cell.categoryRoundBackground.frame.size.height/2;
inside
- (void)viewDidLayoutSubviews {}

You have to Override the method in CustomTableViewCell
- (void)layoutSubviews{
[super layoutSubviews];
self.categoryRoundBackground.layer.cornerRadius=self.categoryRoundBackground.frame.size.height/2;
self.categoryRoundBackground.layer.masksToBounds = YES;
}
and In CellForRowAtIndexPath: you have to write these lines at the end
// Update layout
[cell.contentView setNeedsLayout];
[cell.contentView layoutIfNeeded];
Hope it will solve your problem

Related

Autolayout is breaking when UITableViewCell is scrolled especially for UIImageView

I need UITableViewCell in a dynamic height depends on the content length.
This is a prototype cell
And the content shows fine when first loaded like this
But when I scroll the UITableView, the cell's content breaks like this, especially for UIImageView.
In the implementation of the cell, I only used setImage and setText method.
What seems the problem? Or, is there another way to set each cell's height differently after viewDidLoad?
** Edit: this is my implementation of cellForRowAtIndexPath
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NotificationCell *cell = [tableView dequeueReusableCellWithIdentifier:#"notification"];
if(!cell) {
[tableView registerNib:[UINib nibWithNibName:#"NotificationCell" bundle:nil] forCellReuseIdentifier:#"notification"];
cell = [tableView dequeueReusableCellWithIdentifier:#"notification"];
}
[cell setContent:[notifications objectAtIndex:indexPath.row]];
[cell layoutIfNeeded];
return cell;
}
And setContent in NotificationCell.m has only setText and setImage
Because the tableView already has an imageView property and it is on the left side of the cell, you set the image to that imageView. You should rename the outlet of your custom imageView. So, it should be not called imageView, give the other name for it.

Image on cells not all the way to the left

I am learning about UITableview on iOS and following a course online. I get the table showing fine, but the images on my cells are not all the way to the left (whereas the instructor's ones are). Here is a screenshot of the cells in question:
I don't want that gap, I want the images to be positioned right at the beggining of the cell, all the way to the left. I have done some research and it seems Apple has changed the default look of the cells between ios6 and ios7 so that now the images in cells show a little gap at the left. To get rid of it, I have tried UIEdgeInsets:
[tableView setSeparatorInset:UIEdgeInsetsZero];
and that's not working. I also have tried this approach:
cell.imageView.frame = CGRectMake( 0, 0, 50, 55 );
Nothing happens. So how would I go about it? Thanks
edit-------------------------------------------------------------------------------------------------------------------------------
Still not have found the answer to this. The solutions posted here don't work. I found this piece of code:
self.tableView.contentInset = UIEdgeInsetsMake(0, -50, 0, 0);
Which besides completely puzzling me (as the parameter affected should be the y?) I thought solved the issue by making the image on the cell appear all the way to the left, until I realised it only moved the whole view to the left (as I should have expected I guess) leaving an equal gap on the other side of the screen. All I want is for my images in the cells to appear all the way to the left of the cell as it used to be the case on previous ios. Thanks
It happens because default table content offset from left is 15, you should change it with 0.
See this once, you get idea Remove empty space before cells in UITableView
If you create custom cells. UITableViewCell have owner imageView. Change title of image in your cell.
If you use default cell, use custom cell with constraint Leading space = 0.
It is better not use default imageView of the cell. Drag and drop UIImageView from objective library, create a custom table view cell (Child class of UITableViewCell) then create and outlet of the image view just dragged.
The spacing in the UITableViewCell is because of the default TRUE returned by shouldIndentWhileEditingRowAtIndexPath method of UITableViewDelegate.
I was able to reproduce your problem by the below scenario:
UITableView is in editable mode:
self.tableView.editing = true
And you have implemented:
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView
editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewCellEditingStyleNone;
}
To correct your code:
If you do not want to set Editing Style then you can turn off the editing mode by
self.tableView.editing = false
and remove editingStyleForRowAtIndexPath.
Else if you need editing mode then set the appropiate Editing style(UITableViewCellEditingStyleDeleteor UITableViewCellEditingStyleInsert) or simply turn the indentation off.
- (BOOL)tableView:(UITableView *)tableView
shouldIndentWhileEditingRowAtIndexPath:(NSIndexPath *)indexPath {
return FALSE;
}
You must create a custom cell, by adding a new class as a subclass of UITableViewCell. then you can design cell with autolayout and constraints which will resolve the issue.
there is a another concrete way to achieve this by creating subclass uitableviewcell (custom class).
steps to follow
create a class subclass of UITableViewCell.
in .h file create properties and outlets of UI components.
go to storyboard and add table view cell inside the tableview.
now add UI components like: imageview or button etc and set the x, y values according to.
make class of custom cell your className using identity inspector see image.
connect all outlets of UI components.
use below code uitableview
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSString *MyIdentifier = #"uniqueIdentifire";
yourCustomClassForCell *cell = (yourCustomClassForCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil){
cell = [[yourCustomClassForCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:MyIdentifier];
}
cell.imageView.image = [imageAry objectAtIndex:indexPath.row];
}
Dont forget to give identifire by selecting your cell using storyboard Attribute inspector uniqueIdentifire to identifire property see image.
Also you can give some vertical space between cells by just to add this below code (Method only) inside customeCellClass.
- (void)setFrame:(CGRect)frame { // method to insert gap between table view cell
frame.origin.y += 6;
frame.size.height -= 2 * 6;
[super setFrame:frame];
}
You can not really change the frame of the inbuilt subviews of uitableviewcell like imageview, accessoryview. But if you create a custom tableviewcell class(even if you do not add any other subelement to it), you can change the frame of the inbuilt imageview by overriding the layoutSubviews method inside the UITableViewCell. I have tried it and it works.
#import "TableViewCell.h"
#implementation TableViewCell
- (void)awakeFromNib {
[super awakeFromNib];
// Initialization code
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
-(void) layoutSubviews{
[super layoutSubviews];
CGRect frame = self.imageView.frame;
frame.origin.x = 0;
self.imageView.frame = frame;
}
#end

UITextView setFrame not woking in UITableViewCell

In my UITableViewController Subclass
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"TextCell";
TextCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
[cell setContentText:[texts objectAtIndex:indexPath.row]];
return cell;
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return 200;
}
In my UITableViewCell Subclass
-(void)setContentText:(NSString*)text{
[self.cellText setText:text];
CGRect frame=self.cellText.frame;
frame.size.height=[self textViewHeightForText:text andWidth:frame.size.width];
[self.cellText setFrame:frame];
}
self.celltext is created in storyboard
Problem like this:
First three of the textViews doesn't change their frame.
But when I scroll it down,the textViews below changed their frame.
Scroll back to top again,first three textView changed their frame finally.
Why the first three textViews doesn't change their frame at first?
And how to solve the problem?
The problem is that in cellForRowAtIndexPath:, your cell's frame is not set yet. And later, when it is set, you don't adjust the frame again.
Like all layout in UIView subclasses, the best place to set frames is inside the layoutSubviews method. This method will get called at the right time to set the subviews' frames. Don't forget to call [super layoutSubviews] at the beginning.
Note that it may get called multiple times per instance (it may get called on rotation, or when the status bar frame changes, for example). Therefore, try to keep expensive operations out of here. Since calculating text sizes can be expensive, you may want to cache the result the first time you use it.

UILabel in a UITableViewCell With Dynamic Height

I'm having some problems implemented dynamic row heights in a UITableView - but it isn't the cells that I'm having a problem with, its the UILabel inside of the cell.
The cell just contains a UILabel to display text. My tableView:heightForRowAtIndexPath: is correctly resizing each cell by calculating the height of the label that will be in it using NSString's sizeWithFont: method.
I have a subclass of UITableViewCell that just holds the UILabel property that is hooked up in storyboard. In storyboard I've set its lines to 0 so it will use as many lines as it needs, and I've set its lineBreak to Word Wrap.
Here is how I'm setting up the cells:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
ExpandCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
SomeObject *object = self.tableObjects[index.row];
cell.myLabel.text = [object cellText];
[cell.myLabel sizeToFit];
return cell;
}
When I build this, I get my table view with the cell's all sized to the correct height for their content, but the labels are all 1 line that just runs off the side of the cells. However, if I scroll the table so cell's leave the screen, and then scroll back to them, their label will be resized correctly and the cell will look how I expected it to initially.
I have also attempted calculating the labels frame with the same method I'm calculating the row height with, and I get the same behavior - it doesn't draw correctly until it scrolls off of the screen and back on again.
I have found two ways to work around this, and neither are acceptable solutions.
First, if in viewDidAppear: I call reloadData on my tableview, the cells and labels draw themselves correctly the first time. This won't work for my situation because I will be adding and removing cells to this table, and I don't want to call reloadData every time a cell is added.
The second workaround seems very strange to me - if I leave the font settings at the default System Font 17 on the UILabel, the cells draw themselves correctly. As soon as I change the font size, it reverts to its behavior of not drawing a label correctly until it leaves the screen and comes back, or gets reloadData called on the tableView.
I'd appreciate any help with this one.
I ended up resolving this by alloc/init'ing the label in cellForRowAtIndexPath. I'm not entirely sure why this is a solution - but it appears the problem I was experiencing has to do with how storyboard (or when, perhaps?) creates the objects within the cell. If I alloc/init the label in the cell in cellForRowAtIndexPath, everything loads and sizes correctly.
So... my current fix is to check if the cell has my custom label in it. If it doesn't, I alloc/init the label and put it in the cell. If it does have one, as in its a cell that's been dequeued, then I just set the text in the label that is already there.
Not sure if its the best solution, but its working for now.
I ended up resolving this by unchecking the AutoSizing checkbox in IB. It is unclear why auto-layout was causing this problem.
I ran over the same problem and I end up solving it by calling [cell layoutIfNeeded] before return the cell
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
ExpandCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
SomeObject *object = self.tableObjects[index.row];
cell.myLabel.text = [object cellText];
[cell layoutIfNeeded];
return cell; }

resizing a UITableViewCell frame issue

I am trying to resize my UITableViewCell's frame via:
[cell setFrame:CGRectMake(cell.frame.origin.x,
cell.frame.origin.y,
cell.frame.size.width,
cell.frame.size.height+25)];
however, it's not resizing after I do this... why is this?
This is weird as if I add a UIToolBar into the cell, it resizes but when I am adding a UIView, it doesn't:
[cell.contentView addSubview:sideSwipeView];
Here's the long and short of it:
Your cell width is determined by the width of the tableview it's in.
[EDIT: If it's a grouped table view, the cell is 20 - 60 pixels narrower than the tableview width, depending if you're using an iPhone, or an iPad.]
Your cell height is determined by the heightForRowAtIndexPath method.
If you're manually setting the cell's frame, it's going to be useless except when you're using a subclassed cell where you want to add subviews based on the cell's dimensions.
Even in this case, it's recommended to get the cell's frame from the tableview by using rectForRowAtIndexPath:(NSIndexPath*)indexPath method and then setting that frame as the cell's frame (after setting the frame's origin Y as 0).
I'm not quite sure about the UIToolBar, but your subview's frame won't change on changing the cell frame.
Maybe if you could tell us what you're trying to achieve, we can suggest a solution for you?
--------------------EDIT--------------------
So you need to dynamically add a subview to a cell on tapping it and resize it's height according to the new subview. This is gonna get hairy so here goes:
In your .h file declare:
BOOL subviewAdded;
In your .m file, in the init, do:
subviewAdded = NO;
Let's assume that you want the cell's height to be 50 without the subview and 100 with the subview. Accordingly, your heightForRow method should be:
- (CGFloat)tableView:(UITableView *)tableView
heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return (subviewAdded?100.0f:50.0f);
}
This means that initially since subviewAdded is NO, all your cells will have the smaller height.
Now, to add a subview to a cell on tapping it, and to change it's height dynamically, do this in your didSelectRow method:
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
//Get the cell at this indexPath
UITableViewCell *thisCell = [tableView cellForRowAtIndexPath:indexPath];
if(subviewAdded)
{
subviewAdded = NO;
for(int i = 0; i < [thisCell.contentView.subviews count]; i++)
{
UIView *thisSubview = [thisCell.contentView.subviews objectAtIndex:i];
[thisSubview removeFromSuperview];
}
}
else
{
UIView *someView = [[UIView alloc] initWithFrame:someFrame];
[thisCell.contentView addSubview:someView];
[someView release];
subviewAdded = YES;
}
NSMutableArray *array = [NSMutableArray array];
[array addObject:indexPath];
[tableView reloadRowsAtIndexPaths:array
withRowAnimation:UITableViewRowAnimationFade];
}
So what's going to happen here is you're adding a subview to this cell you've tapped. Reloading this cell will call heightForRowAtIndexPath and do a nice little fade animation and change your tableview heights.
IMPORTANT: Ideally, you should maintain an array of NSNumbers with boolean values. The array size should be the same size as the number of tableview cells you have.
In heightForRow, you would then check against this array instead of using a single boolean for the whole tableView. This would ensure that you could have different heights for different cells.
That would look something like:
- (CGFloat)tableView:(UITableView *)tableView
heightForRowAtIndexPath:(NSIndexPath *)indexPath {
BOOL thisBool = (BOOL)[[booleanArray objectAtIndex:indexPath.row] boolValue];
return (thisBool?100.0f:50.0f);
}
I didn't post all that code here since it's implied and what I've posted should put you well on your way to doing the boolean array thing.
Anyway, there you are. I just tested this code myself so it works :)
If you want to increase the height of your cell based on some parameter eg. text, image,
you must implement the heightForRowAtIndexPath method of UITableViewDelegate in your code.
- (CGFloat)tableView:(UITableView *)tableView
heightForRowAtIndexPath:(NSIndexPath *)indexPath

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