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.
Related
I have a UITableView cell that is going to have a variable size depending on it's content (potentially several lines of text).
Since it appears that heightForRowAtIndexPath is called before I layout the cell, I just guess the correct height by calling [NSString sizeWithFont] on my text string. Is there a better way to set the height after I've laid out the text in the cell and have an idea of exactly what size it should be?
My problem is each cell contains a UIWebView with different (statically loaded) content I can't figure out how to calculate the proper height based on the content. Is there a way to do this? I've tried things like this:
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
WebViewCell *cell = (WebViewCell*)[self tableView:tableView cellForRowAtIndexPath:indexPath];
[cell setNeedsLayout];
[cell layoutIfNeeded];
return cell.bounds.size.height;
}
The cells themselves are loaded from a nib, which is simply a UITableViewCell containing a UIWebView. (It would also be fine if the cells just adjusted themselves to the largest of the html content, though variable height would be nicer).
- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath: (NSIndexPath *) indexPath {
UITableViewCell *cell = [self tableView: tableView cellForRowAtIndexPath: indexPath];
return cell.bounds.size.height;
}
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
I have a custom UITableViewCell. I want to access the cells properties i.e. a UILabel etc. I tried inserting the following code:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
CategorieCell *customCell = (CategorieCell *)[tableView cellForRowAtIndexPath:indexPath];
return ...
}
When I run the app, it crashed without giving me error details. The problem is with the new customCell I'm creating. Is there another way I can access the customCell.m objects?
About the crash, please note that you are using cellForRowAtIndexPath: wich is a method from the UITableViewDatasource that you have to implement, this method calls heightForRowAtIndexPath by default, so it will become a recursive
I assume that you want your custom cell in this method in order to get the height from it.
The best way to achieve this is write a class method on CategorieCell that gives you the height for a cell with certain data.
Other option is extract a method with the code to get the uitableviewcell for example
(CategorieCell*) categorieCellForIndex:(NSIndex)index selected:(BOOL)selected{
...
}
In heightForRowAtIndexPath should never be called cellForRowAtIndexPath.
The first one is called before the second one, and if you need to access to a label (for example to calculate the height of the text) you can normally init a cell.
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
static CategorieCell *cell;
if (!cell) {
cell = [tableView dequeueReusableCellWithIdentifier:#"CellIdentifier"];
cell.frame = CGRectMake(0, 0, tableView.frame.size.width-tableView.contentInset.left-tableView.contentInset.right, cell.frame.size.height);
[cell layoutIfNeeded];
}
cell.label.text = myDatasourceText;
CGFloat cellHeight = ....
return cellHeight;
}
NOTE 1:
I used dequeueReusableCellWithIdentifier supposing you are using Interface Builder, otherwise you need to use alloc] initWithStyle:...];
NOTE 2:
As you see I'm setting the frame of the cell. This is needed because otherwise your cell will be (320 x 44) as default. You instead could be in iPhone 6/6+ (i.e. screen width: 414) or in an iPad, and you could need to calculate an height of a label according with his width and his text, and for this reason you need to set the frame of the cell.
NOTE 3:
I'm assuming you have a set of equal cell structure, and for this reason I'm using a static cell, so it will be reused without allocate other useless cells.
Try to register your custom cell class like so:
[self.tableView registerClass:[CategorieCell class] forCellReuseIdentifier:NSStringFromClass([CategorieCell class]);
and then in -tableView:heightForRowAtIndexPath: do something like:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
CategorieCell *cell = [tableView dequeueReusableCellWithIdentifier:NSStringFromClass([CategorieCell class)];
}
I have a UIViewController that contains a UITableView. In my table view I have a prototype cell in which I want to place custom labels. I cannot get any of my custom labels to render in the cell. The datasource and tableview delegates are connected and functioning properly. For my first attempt, I dragged a UILabel control onto my prototype cell. I set its tag to 1000. Here is my code to populate the cells:
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *cellID = #"cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellID];
UILabel *customLbl = (UILabel*)[cell viewWithTag:1000];
if(indexPath.section == 0){
[cell.textLabel setText:[rData.currentHeightReadings objectForKey:[heightKeys objectAtIndex:indexPath.row]]];
[customLbl setText:#"CFS"];
} else {
[cell.textLabel setText:[rData.currentFlowReadings objectForKey:[flowKeys objectAtIndex:indexPath.row]]];
[customLbl setText:#"Ft."];
}
return cell;
}
The default textLabel for each cell renders as it should. However, the custom label does not appear. I verified that the prototype cell was actually rendering by changing the background color of the cell's content view. In my story board I have set the prototype cell's reuse identifier to match my code. The style is set to 'Custom.' What else should I be doing? Thanks!
Verify that your autolayout constraints are correct such that the UILabel is really positioned where you expect it.
I had the same issue once and I've solved it by not calling any methods to cell.textLabel property. Just don't set its text in any way.
Try it out and report back.
Try this:
UILabel *customLbl = (UILabel*)[cell.contentView viewWithTag:1000];
When I push a UIViewController onto my UINavigation controller like:
[(UINavigationController *)self.parentViewController pushViewController:[[[Fonts alloc] initWithNibName:#"Fonts" bundle:nil] autorelease] animated:YES];
Where Fonts.xib is a UIView with only UITableView controlled by a Fonts object that is a subclass of UIViewController and acts as the UITableView's dataSource and delegate.
In the Fonts object I create a UITableViewCell like:
- (UITableViewCell *) tableView: (UITableView *) tableView cellForRowAtIndexPath: (NSIndexPath *) indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: #"BlahTableViewCell"];
if (!cell) {
cell = [[UITableViewCell alloc]
initWithStyle: UITableViewCellStyleDefault
reuseIdentifier: #"BlahTableViewCell"];
[cell autorelease]; // Delete for ARC
}
return cell;
}
And then I change the font of the cell here:
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
[cell.textLabel setFont:[(UIFont *)[self.listOfFonts objectAtIndex:indexPath.row] fontWithSize:cell.textLabel.font.pointSize]];
cell.textLabel.text = [(UIFont *)[self.listOfFonts objectAtIndex:indexPath.row] fontName];
}
listOfFonts is an NSArray of UIFont objects.
When the view appears it looks like UITableView without changed fonts
If I call reloadData on the UITableView or if I drag the UITableViewCells off screen with my finger and let them bounce back they are redrawn and the view the cells display with the labels having their fonts changed.
It seems like the issue is the UITableViewCells are being drawn too early. If I delay the drawing of them everything looks correct but I want the UITableView to be displaying correctly when the UINavigationController slides my view into place.
Any idea what I am doing wrong?
EDIT: I uploaded a simple and straightforward example of my issue to Dropbox. http://dl.dropbox.com/u/5535847/UITableViewIssue.zip
SOLVED IT!
Ok so I was having exactly the same issues as the original poster and this was the problem.
The line that's causing issues is:
[cell.textLabel setFont:[(UIFont *)[self.listOfFonts objectAtIndex:indexPath.row] fontWithSize:cell.textLabel.font.pointSize]];
Specifically, your issue is because you're trying to feed the cell's textLabel its own pointSize, but pointSize doesn't exist yet so strange bugs occur instead. For me, I noticed that a "transform" was failing due to a singular matrix being non-invertible. As soon as I hardcoded a standard value as my pointSize I saw all my labels draw with the proper font instantly. Note: this makes sense as to why a redraw worked, because then your textLabel does indeed have a pointSize.
In any case, you need to explicitly set your pointSize here, no using what the textLabel "already has" because it doesn't have anything until you're "reloading" a cell.
Set the label font inside -tableView:cellForRowAtIndexPath:.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *identifier = #"identifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier] autorelease];
// do it here if your font doesn't change ....
}
// otherwise here with your font ...
cell.textLabel.font = [UIFont boldSystemFontOfSize:12];
return cell;
}
I'm not sure that table cells are designed to be customisable in this way. The table cell may assume that you won't customise the font, and so not draw itself in a way that's compatible with what you are trying to do.
You'd be better off creating a custom table cell, or appending a UILabel as a subview to the table cell when you create it, and them setting the font of that label instead.
It may seem like overkill for such a small customisation, but it's flexible and it's guaranteed to work.