I want to add a UIPickerView to a UITableViewCell. Right now I am just getting a black window. Can someone also explain me the concept of subclassing UI objects to a cell ie:when do we make our cell as the delegate and the datasource delegate? Thanks
EDIT: Here is the code of what i am doing right now
case 1: {
cell = [tableView dequeueReusableCellWithIdentifier:#"groups"];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"groups"];
}
/*NSString *myGroupDetail = [_groupArray objectAtIndex:indexPath.row];
NSLog(#"the group detail label is %#",myGroupDetail);
cell.textLabel.text = myGroupDetail;
*/
[cell addSubview:_groupPicker];
break;
}
The groups is the section in which I want the picker view, I am getting that data from an array.
you would have to allocate and initialize a pickerview in your cellForRow method of the tableviewdelegate. ill sketch it for you =) how to initialize a cell itself should not be hard to find out if you google a bit ;-)
...(tableView *)... cellForRowAtIndexPath... {
if(indexPath.row == pickerRow){
UIPickerView *pickerView = [[UIPickerView alloc]init];
cell = ... // alloc and initialize a cell
cell addSubview:pickerView];
}
else{ // your other cells }
return cell;
}
UPDATE: im currently having trouble with git, so i uploaded a sample project to my private server: UITablePicker example
github: https://github.com/sebamisc/UItableViewWithPicker
yu can modify and use the code however you want =)
sebastian
Well, I never did exactly that.
Does it have to be in a cell or could you use the table's header or footer view for that? (I would not suggest a section header/footer view.)
Assuming it is within a UITableViewCell.
Yes, I personally would subclass UITableViewCell. Did that a lot. In that case you cell object could be the data source delegate of the picker. For doing so your subclass of UITableViewCell (let's assume you name it MyTableViewCell) needs to fulfil the related protocol. You add that UIPickerView programmatically within the init Method (initWithStyle) of MyTableViewCell. For the layout within the table cell, you should overwrite the method layoutSubviews. If your app can be rotated to landscape and portrait orientations and/or if your app is designed to run on iPad as well, then this method should dynamically consider the table's bounds. (Screen or windwo bounds are often used hiere but that is not save when the table is displayed within a split master view or a popup view on iPads.)
Strictly spoken your MyTableViewCell should not be the data source delegate, simply because it is a view element and view objects are not supposed to manage any business logic within an MVC design pattern. Smarter would be the implementation of some dedicated view controller for your table view cell hat fulfills the protocol and is assigned as the delegate. However, both would work. In the event that it is the only picker view within your sell, then you could easily use your UITableViewController subclass even without tagging the UIPickerView.
An alternative to subclassing a UITableViewCell is to create the UIPickerView within the cellForRowAtIndexPath method of your tableViewController. That is fine for singe-orientation apps. However, you may setup it in a way that it re-arranges its the UIPickerView automatically.
In any case you should overwrite the heightForRowAtIndexPath method of UITableViewController when your table views do not have the same hight any more. If all of them still have the same height, then you can simply set the rowHeight property of your UITableView.
Related
I have custom cell created with nib. In the table view I am using the method -(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath to set the height of cell
Everything works fine.
But the problem is that I also want to change the size of UIlabel which is added as subview in nib of cell.
How do I do that?
Which metod to override in customcell class ?
The method you are looking for is:
-(void)layoutSubviews
{
[super layoutSubview];
//Do your magic
}
layoutSubviews is call after the cell is created and whenever the device orientation changes, to allow you to resize and/or move the subviews (plus make any other minor adjustments) to compensate for differences between the orientations, but in this case you can also use it to redraw your subviews.
As you have UILabel in your custom cell class, make a function in that class that take frame you want to set as parameter. Set frame of label in that function. You need to call this function from your cellForRowAtIndexPath method before returning the cell.
If you are reusing your custom cell you should call method only when the (cell == nil)
Also if you can add some code in your question that would be helpful and you can get more precise answer.
You need to treat your custom cell in the same way you would treat a normal view or view controller class with a xib. i.e. You need to create IBOutlets for the controls in you custom cell and during creation of the cell you can access the controls quite easily.
myCell.myCustomUILabel.text = #"blah"
There are some gotchas when using custom cells in a xib and onnecting up the IBOutlets. This SO answer (of mine) explains how to create and link up IBOutlets of a custom cell.
Using storyboard, static cells, in cellForRowAtIndexPath: the line
UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
always returns nil.
I have checked the following:
Identifier of the cell is correctly set in IB/Storyboard and I use the same identifier in code. I verified this many times.
I have not instantiated the view controller elsewhere (which was the problem in this stackoverflow question).
My view controller is a subclass of UITableViewController, of course, wrapped into an ad hoc navigation controller in storyboard. Suspecting that my view controller somehow does not know about the cell identifiers defined in storyboard because it might be another instance, here is the code the "instantiates" it. In prepareForSegue:, I use
CustomViewController *vc = [[[segue destinationViewController]
viewControllers] objectAtIndex:0];
Other customizations of the view controller done here (setting properties etc.) works fine.
I am using static cells because the number of sections and rows does not change, and each cell contains static text (and other controls or text fields to be edited).
It seems to me this is a very common task (customize static cells from storyboard in the view controller's datasource methods). What am I doing wrong?
With static content in a table view, you do not implement any of the datasource methods (including tableView:cellForRowAtIndexPath:, so you would never dequeue the cells. There is no dequeuing for static content (that you can get involved in, anyway).
If you want to get a pointer to a particular cell:
get it from the table view using cellForRowAtIndexPath::
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
have an outlet to the specific cell and customise it directly.
Iterate through the cells and check the reuseIdentifier property to get the cell you are interested in.
Any of these things can be done in viewWillAppear or similar.
If you want to have completely different content in your cells to that found on the storyboard then static cells probably aren't the right choice. You should use dynamic prototypes (note you can have multiple prototypes in the storyboard) with the traditional data source methods instead.
You can still use dataSource/delegate methods of static UITableView, you just don't have to create new cells.
If you want to modify cells with dataSource methods, inside cellForRowAtIndexPath: :
UITableViewCell * cell = [super tableView:tableView cellForRowAtIndexPath:indexPath];
and then start modifying cell.
The solution was to use prototype cells rather than static cells. I am still giving the check to #jrturton as he was the first who got me the idea.
Another interesting error I just solved: with prototype cells of type "Custom", if you try to fill cell.textLabel with text, it will just automatically work, but all your other subviews behave very strangely. I just use my custom label now, and everything works fine.
Cheers, thanks everyone for helping out.
Different to the answer above,
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
will not work. But the mentioned method to create an outlet to the cell itself is working.
It is also possible to place views such as UIButtons or UITextFields on the cell and have outlets for those as well.
Both methods can also be used in combination. E.g. set the cell.textLabel.text for a particular cell and have another control which will be accessed from the controls outlet.
In the storyboard, the Static Cells CAN'T implement the Methods in the <UITableViewDataSource> protocol.
So you could use the methods which ones are include in <UITableViewDelegate>.
I know this is a very old question, but the better way to handle this is to use tableView(_:willDisplay:forRowAt:)
I need a way of setting the UITableViewCellAccessory for any row. However the catch is that I need to be able to do it OUTSIDE of the UITableView delegate methods.
I have tried this, but it doesn't show up the accessory.
[[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathWithIndex:1]] setAccessoryType:UITableViewCellAccessoryCheckmark];
If it makes any difference I created the UITableView in IB in a storyboard. The data is static, and I'm using a grouped table style with only one section.
Please can someone help me out?
If your table view is scrolled so the cell in question may sometimes scroll out of view and then back into view, you should manage the content of that cell only from within the UITableView method cellForRowAtIndexPath:. The reason is that when cells are redrawn, the tableview object calls this method to make sure that visible cells are properly rendered. (Cell that are not visible don't need to be rendered at all.)
That being said, this is where you should handle the cell content, even if the table view doesn't scroll the cell in question out of view. It wil lmake you life a lot easier if you follow this design pattern when working with table views.
Inside that method, you can test (using if statement, for example) the value of the indexPath.section and indexPath.row so that you can configure the specific cell the way you want it. This includes putting in the accessory.
Always use [NSIndexPath indexPathForRow:inSection:] when working with table views.
You can figure out what indexPath you need the checkmark on and then use something like this
UITableViewCell * cell = [tableView cellForRowAtIndexPath:someIndexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
I have a TableView with one cell and I want to insert in this cell a lot of text so I think I'll need to use a ScrollView for scroll the text.
How can I insert? Is correct this method?
This is a help in the application, is correct use this modality?
Sorry but I'm a beginner and I don't have an iPhone or iPod, thanks!
While I concur with 7KV7's original comment, it doesn't look like there is need of a tableview in this scenario...
Just in case someone else happens upon this looking for an answer to the "Scrollview in a Tableview" question here are few clarifying points for the above comments.
The technical problem with having a tableview and a scrollview together on the same view is that UITableView is already a descendent of UIScrollView and if you attempt to handle both in the same view then you will end up with quite a mess with conflicting delegate messages.
As suggested by iPhonePgr, you can create a custom UITableViewCell. The first thought would be to let the UITableViewCell act as the delegate for it's own scroll view. The problem here is that the cell and it's contents could be discarded or reused at any moment as part of tableview's dequeue functionality.
So some ground rules to guide your implementation:
Whatever your solution, you're probably going to end up making a custom controller class, possibly derived from NSObject and implementing UIScrollViewDelegate.
The custom controller object acts as the mediator between the model object and the cell.
You will probably have an array or array-of-arrays that mirrors the model hierarchy driving the UITableView structure.
Because the cells can be discarded at any time you will have restore the scroll view state on cell initialization and preserve the state has part of handling your delegate actions or through a custom UITableViewCell implementing prepareForReuse.
Hopefully these points will come in useful to anyone who runs across this entry.
You need to create a custom cell by inheriting UITableViewCell and then add UIScrollView in the customcell. Then Use that cell in the Table view.
you can put your text in UITextView and add it as a subview in your UITableViewCell,because
UITextView is inherited from UIScrollView,
No need to add UIScrollView if you use UITextView
When you create UITableView you implement a number of delegate method which you can see by pressing the window key and then double clicking the UITableView delegate . In one of the methods you can set the cell height as per your requirement. By doing this your cell height can vary.
- (CGFloat)tableView:(UITableView *)resultTableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 150;
}
As your table has a defined height, when the text in cell will be too much to contain into a scrollview will be automatically inserted.
I have a tableView that's loosely based on the DetailViewController in ye olde SQLiteBooks. It's created programatically. Each cell displays a single value that when clicked displays a generic editingController that allows the user to edit that value. Pretty standard Cocoa-touch stuff...
Except...I also have a segmented control in the header of said tableView that depending on it's setting needs to change an attribute (textColor) on a UILabel in ONE of the 8± tableViewCells in the table. I have no IBOutlets for this tableView because I created it entirely in code. So, what do I need to do in my (void)segmentAction:(id)sender method (triggered when segmentedControl changes state) to allow me to access & change this value and display it to the user? When the table was built (cellForRowAtIndexPath) every UILabel was called "value" and then added: [cell.contentView addSubview:value].
I've tried setting a property of the viewController itself that is then checked during cellForRowAtIndexPath and does the textColor business there...and then adding [self.tableView setNeedsDisplay] to my segmentAction: method but it doesn't seem to work?!?
Any ideas?
If you know the indexpath of the cell you want to modify, you can call cellForRowAtIndexPath: to retrieve the UITableViewCell. Once you have that, you can get the UILabel from it. If you set the UILabel's tag to some useful value when create it, you can then retrieve it from the UITableViewCell via viewWithTag:.
In the class that implements cellForRowAtIndexPath you could also store a reference to the UILabel that you want when you build the relevant cell.
This would then mean you could alter the label and mark it to be repainted.
Alternately you could hold a local BOOL to show that the cell should be drawn differently - and then use this this in the cellForRowAtIndexPath: to draw it with a background.
You might find this easier with the 3.0 textLabel object in a UITableViewCell