I have used a simple prototype cell from storyboard for adding header view to my table view. I added some labels in cell and give specific tag to every label, but while accessing it returns me nil value for [cell viewWithTag :] method.(I have not created a custom class for cell) I am using following method
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
UITableViewCell * headerView = [tableView dequeueReusableCellWithIdentifier:#"HeaderView"];
UILabel * lblVenueName = (UILabel *)[headerView viewWithTag:100];
lblVenueName.text = #"Test Venue";
return headerView;
}
for above code the value for lblVenueName always return nil.
I ran into this problem in XCode 7.0 beta 5 (7A176x). I suppose it's a bug. I've checked in debugger and turns out that cell contentView does not have any subviews at runtime.
If you are designing for some specific screen size then this workaround may help you. Switch to the base values like this:
Then in attributes inspector check that both "installed" options are checked on all views that you need and their superviews (for example for all views in prototype cell, table view and it's superview):
After that you can return to your specific screen size and viewWithTag() will return correct values.
(id)dequeueReusableCellWithIdentifier:(NSString *)identifier
Return Value
A UITableViewCell object with the associated identifier or nil if no such object exists in the reusable-cell queue.
So I'm guessing that method returns nil for you :) Try a version that takes a indexPath :)
Related
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
Current I am creating a prototype cell in storyboard and using this cell as a section header.
Inside tableView:viewForHeaderInSection: method, I am dequeuing the cell and returning it.
My section header cell has a UITextField and a UIButton in it.
When I tap on text field keyboard appears but as soon as focus is moved away from text field whole section header disappears.
This happens when I return the cell directly as section header view, but if I return a newly allocated UIView as section header view onto which cell is added as subview then everything works fine besides autoresizing masks.
Why header is disappearing?
I am not sure what could be the best thing todo here.
-(UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
static NSString *CellIdentifier = #"SectionHeader";
SettingsTableViewCell *sectionHeaderCell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
//return sectionHeaderCell; // returning cell directly, section header disappears when focus is moved away from text field.
UIView * headerView = [[UIView alloc] initWithFrame:sectionHeaderCell.frame];
[headerView addSubView:sectionHeaderCell];
return sectionHeaderCell;//header view never disappears, but auto resizing masks do not work. Need to know how to set autoresizing masks to headerView so that it resizes correctly.
}
Prototype cell table views only allow you to design cells in the storyboard editor, not section headers and footers. Your attempt to use a UITableViewCell as the section header is a clever hack, but it's just not supported by the classes involved—UITableViewCell is not designed to be used for anything other than a table view cell. It could do a lot worse than the view disappearing or not being laid out correctly; UIKit would be well within its rights to fail an assertion, delete all the app's data, revoke your developer certificate, or set your house on fire.
If you want your code to function properly, your choices are to either create your section headers in code or to put them in a separate XIB file. I know that's not what you want to do, but those are the options you have.
I had the same issue and the fix was to return the cell's contentView like:
-(UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
static NSString *CellIdentifier = #"SectionHeader";
SettingsTableViewCell *sectionHeaderCell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
sectionHeaderCell.myPrettyLabel.text = #"Greetings";
sectionHeaderCell.contentView.backgroundColor = [UIColor whiteColor]; // don't leave this transparent
return sectionHeaderCell.contentView;
}
And you get the same autolayouted results as before, but without the disappearing.
I am sure you can use UITableViewCell as a section header, because UITableViewCell is subclass of UIView, so according to LSP
“objects in a program should be replaceable with instances of their
subtypes without altering the correctness of that program.”
In iOS 8, it's simple really. Just design your header the same way you design your cell. Everything is the same, you can put custom class and don't forget to add reuse identifier.
When it comes to use it in the code, just return that cell in tableView:viewForHeaderInSection method.
Don't forget to implement tableView:heightForHeaderInSection if you want to use fix height or tableView:estimatedHeightForHeaderInSection if the height depends on the cell intrinsic size.
I place textview in the prototype cells by storyboard and assign the textview's tag.
In the implantation method of
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:,
I wanna assign the textview another identifier so that I can obtain the textview by this identifier. The reason why I don't use the TAG property to do this is because that all the cells in my table view has the same prototype for reusing.
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell"];
ETPost *post = postList[indexPath.row];
UITextView *textView = (UITextView*)[cell viewWithTag:TEXT_TAG];//TEXT_TAG 1000
textView.text =post.content;
return cell;
}
as you can see above, I use the viewWithTag, all the cells in my tableview have the same tag, so I have to another solution instead of assigning the indexPath to the TAG.
Alright, the answer is probably simpler than you think. But just subclass UITableViewCell and make sure that your table view is using your new subclass (you set this up in the prototype cell Custom Class in IB and StoryBoards). The only thing the subclass adds is a property that allows you to identify it.
#property short specialIdentifier;
Here's a more general link on UITableViewCells which I generally refer to when I need something done: cusomizing uitableviewcells
in -(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath: you could assign the indexPath's row number to your textView's tag like:
cell.textView.tag = indexPath.row;
so this tag would correspond with your cell's indexPath distinct assuming you place all cells in ONE section.
I have a UITableView that I want to alter some of the static cells after I do other processing. I have outlets set up for the cells that I want to modify, but when I look at them using NSLog, they show nil, which indicates to me that I don't have the correct cell. For instance, in the image below I want to add the start time to the label just like I did for Date (date was done when creating the cells for which I got the current date),
I tap on the disclosure indicator which takes me to another scene (this was created in Storyboard, using segues to get from one scene to another) where I get the two times I need. I then return to the main scene (shown) and try to alter the Start Time label, but nothing happens. A NSLog of the label prior to trying to alter it returns this:
oStartTimeCell.textLabel.text: (null)
I have read in one of the Apple docs that this textfield is read-only. If that is true in this case, is there a way I can reload the cells with the updated information? Or is there another way to do this?
You're using the wrong approach. You should not create a reference to a cell using an outlet. Once the cell moves out of the visible view, the outlet will either be null or contain garbage data. Even if (in your situation) the cell will never move out of view, I think it shows you're trying to use a UITableView in a way that was not meant to be.
Instead put the data you want to display in your cells in a dataSource, e.g. an array.
The tableView should use the dataSource to configure the values displayed in the textLabels of the cells. Once you want to update the text displayed in the cells, change the values in the dataSource and call reloadData on the tableView to force the tableView to call -tableView:cellForRowAtIndexPath: and related UITableViewDataSource methods.
Try to create an IBOutlet for each cell and connect it:
IBOutlet UITableViewCell *cell1;
IBOutlet UITableViewCell *cell2;
IBOutlet UITableViewCell *cell3;
And also change your method to:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(indexPath.row == 0) return cell1;
if(indexPath.row == 1) return cell2;
if(indexPath.row == 2) return cell3;
if (cell == nil) {
//create cell;
}
return cell;
}
Are you using a UILabel to display the text ? . If you are just create an outlet to the UIlabel and update it any method like cellForRwoAtIndexPath or didSelectRowAtIndexPath etc that is called after you tableView is loaded.
If you are not using a UILabel and just using cell.textLabel you could do something like
cell.textLabel.text = #"ChangedText" in cellForRowAtIndexPathMethod. Make sure you are editing the required cell by checking indexPath.row
Do [tableView reloadData] to call cellForRowAtIndexPath.
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; }