I have a cell in the UITableView. The cell has a UITableViewCell class. In this class I programmatically add few buttons.
Note: the cell is located in the very end of the table view.
Issue:
If I'm using simulator iphone 5 > the buttons will be shown.
But if I'm using simulator iphone 6+ > the buttons will NOT be shown.
Note: when i'm opening it on iphone 5 I need to scroll to see that particular cell. on iphone 6+ i don't need to scroll there, the cell is visible right away.
So I think the issue is somewhere here. May be with the place where I do my 'buttons adding'.
Where should I call the method that sets up the buttons?
Or how can I solve this problem?
TL;DR: If you have different cell types in your table view, you should make sure they have different identifiers.
Explanation:
Table cells are re-used within the UITableView and when the table is first being displayed it won't have any re-usable cells yet. It gets the cells to display by calling on its data source through the UITableViewDataSource protocol.
The thing providing the cells will first ask the table view if it has any re-usable cells (of a particular type), before creating a new one. The way it determines the particular type is from the reuseIdentifier in the table cell.
So, if you have two different classes of table cell, but they share the same reuseIdentifier you will sometimes get one class and sometimes the other - if you get the one without buttons when you're expecting the buttons then this will be a problem!
The answer is to make sure your different cell types have a unique reuseIdentifier.
Related
I have a UIViewController with a collectionView inside it. The layout may seem confusing but I am making use of horizontal scrolling UICollectionViewCells, presented in 3 sections.
The main collection view is made up of 3 sections. I access 3 different UICollectionViewCell classes for each section becuase it is fetching different data for each one. Once the data is fetched, it dequeues another Cell class, which is the same one accessed for all the sections.
There are 2 buttons in each cell. When I press the button, a value changes within the database. When I re-run the program, the cell in which the button was pressed has moved to its corresponding section that it should be in as per the change. However, I want to achieve this as soon as I press the button. How can I move the cell from one section to another, baring in mind that they the cells presented are inside a collectionview cell making up the sections, which is then inside a greater UICollectionView.?
I've tried researching how to do this but no luck, and everyone seems to be using a drag and drop method which seems too complicated for what I am trying to achieve. Would appreciate any help.
Thanks
The approach I followed to achieve the above situation is using a custom Delegation when cell is removing from collectionviews. A container CollectionView has two sections with 2 different cells containing two different Horizontal UICollectionViews. These two collectionview's cells have UIButtons. When tap on one collectionView's button, that particular cell is removed, custom Delegate method calls and another CollectionView's cell is populated. This is the link of the project I have created for this particular scenario. For better understanding, here is a GIF for demonstration.
I am just thinking. Suppose, i have a tableview which have custom cell. It's simple. But My idea is that, when i click a tableview cell then another tableview is appear under that tableview cell, and again i click that cell then that sub tableview disappear. Similarly when i click second cell than work same. Is it possible? Please Provide me any idea or reference.
This is entirely possible, you're talking about Expandable cells.
My example here
The general idea is that your custom cell has a tableview at the bottom of the cell, and what you do is just change the cell height to display said tableview, on tap.
It's not easy, I'm not gonna lie it took us a while to do it, but we managed, and I'm telling you, it's very possible.
You can find a lot of help using the Expandable Cell keywords.
Note that you're gonna find yourself handling a lot :
What to do when the expanding cells is shown off screen?
What to do when you're expanding the first/last cells ?
What to do when expanding another cell ?
What to do when scrolling inside that cell (a scrollview inside a scrollview !)
There are many cases where it'll work, but won't work fine, and there is gonna be a lot of fine tuning. Specially in our case where we have rounded corners, but only when the cell is expanded, and not in cases where it's the last or first cell (next to section header).
They look cool and make you feel proud, but don't say to your PM it'll be done in a week, because it's a pain to build.
If you want to show additional cell information, you can add more cells after the cell indexpath you have clicked.
Create a custom table view cell classCustomTableViewCell by subclassingUITableViewCell class. And system will generate CustomTableViewCell.h, CustomTableViewCell.m, CustomTableViewCell.xib files for you.
Add protocols UITableViewDataSource and UITableViewDelegate in your CustomTableViewCell.h and implement the required methods in CustomTableViewCell.m files
Add a method for setting datasource and use the datasource for updating the table.
NOTE:
Handle table-dequeue mechanism properly, otherwise you will end up
with weird issues that may take time to investigate and resolve.
If you use this custom cell for all the cells in your parent table then the gestures will only listened by the child table. So plan for that too.
Please visit my blog for the sample code. https://myioslearnings.blogspot.in/2017/03/nested-table-view-in-ios-objective-c.html
I need to display a table with in my iPhone app:
neither the number of cells nor the contents are known at compile time, but only at run time.
Views for each cell may differ, one cell has textField and another may have some other view control.
Should I consider Static or prototype cells?
Should I consider tableViewController or viewController with tableview in it?
Any thing I need to consider before I start coding? Thanks in advance
For The issue of dynamic Number of cell at Run time, you can call reload data for table view at any time you have the data source ready.
Prototype Cells should be used with no problem.
Simple Table View will be sufficient for the task.
You have to make cell, either in code or in storyboard, for each type of cell you want, 1 table View can have multiple types of prototype cells, Just name them differently and then make the objects of only the specific cell of which the data is best suited.
It is not that difficult but do handle the data source with extreme care.
Should I consider Static or prototype cells?
If you know all possible subview combinations that your cells might need to display the data appropriately, and they are relatively few, make one prototype for each. for example:
One text field,
Two labels,
One image view and a label,
...etc.
Otherwise, just use the plain-vanilla UITableViewCell (no subclassing) and remove/add subviews at runtime when reusing them (that is, inside the method -tableView:cellForRowAtIndexPath:).
Should I consider tableViewController or viewController with tableview
in it?
The only reason I would choose UIViewController + UITableView over UITableViewController is if -for example- I needed the table view to only take up part of the main view's bounds/screen, and display some other subview in the remainder. Otherwise, you get so much "for free" with UITableViewController that there's just no point in implementing all of that from scratch.
You have to choose prototype cell, u can create different types of cell depending upon your requirement.Any think ok for u, u can create tableview controller or view controller.
I'm creating a Table View in Interface Builder (Storyboard). I'd like to have a couple of different Dynamic Prototype cells with different sets of Labels and Images in them and so on, and I can give them different reuseIdentifiers so I can pick which ones I want at runtime.
In Interface Builder, I create several Dynamic Prototype cells in my UITableView, which is controlled by a UITableViewController.
In the first cell, I drag and drop in various views and so on.
In the second cell, IB will not let me drag any views into it? I can resize the second cell vertically, but can't put anything into it at all, either by dragging into the cell or into the object graph in the left-side bar.
If I copy and paste the first cell, a second Dynamic Prototype will appear with all of the same contents, but I won't be able to modify the copied cell (can't add or move subviews). However--and this is strange--I can select the constraints and modify their values to resize and shift objects in the second cell.
As a note, running XCode 5-DP3. Tried restarting it (didn't expect that to help, and it didn't). Otherwise, unsure what to try, and unsure if I'm doing something very braindead, or if this is a bug I need to report to Apple.
So, am I crazy? Has anyone experienced this/can anyone recreate this?
EDIT:
After further testing, if I stick a big UIView into the first cell, and then copy that cell, I can edit inside my added view. (Does this make sense?) I can't edit anything that lies within the second UITableViewCell, but if it contains a UIView copied over from the first cell, I can put new views into that view and move them around and so on. Super-strange.
For the sake of posterity, I'm answering my own question:
The way I solved this was to take a UITableViewCell object from the Object library and drag it onto the UITableView. Sounds simple, right?
The problem I was running into was only if I copied existing dynamic prototypes through Cmd+C & Cmd+V, or by incrementing the number in the Attributes inspector for the table view. The Storyboard Editor wouldn't allow me to modify those ones.
Dropping in new cells from the Object library let me tweak them all separately.
XCode 5-DP6 solved issues with not abling to resize cell's subviews.
I'm new to iOS and MonoTouch, and I have a pretty basic need - I have two vastly different views to display in the same table cell depending on whether it is selected or not. When you load the app I'll present a list of products in a custom UITableView, with all the rows deselected and each row basically just showing the product names in a label. As soon as a user taps one of the rows and selects it, I show a very different view with more of a shopping cart layout. Since the two views are so different they have vastly different sizes. What i need is for the cell itself (or row?) to grow and shrink according to the natural height of whichever view is currently being displayed.
I'm using descendants of UITableViewController, UITableViewSource, and UITableViewCell for the solution. What I do is add both versions to the cell's ContentView, then set the Hidden property as needed when the cell/row is selected/deselected to show the right layout. That works well. I'm in demo mode right now, so I'm not overly worried about efficiency or responsiveness, that will have to come later.
I know that GetHeightForRow is responsible for sizing the rows but it only gets called once, when the cell is first shown. It seems to me that I need to alert the TableView to re-poll the source for a new size as the views are changing, but I can't figure out how to do it.
I tried (rather hopefully) to cause GetHeightForRow to be invoked again manually using Cell.SetNeedsLayout and Cell.SetNeedsDisplay, hoping that would cause the table to re-query the source for new dimensions, but no joy.
I tinkered with the direct approach, trying to size the contentview itself but it didn't seem as if it was leading anywhere. I feel as if the table needs to be told to query for a new row size, but I'm open to any suggestions.
Surely I'm not the first to attempt this? What am I missing?
Try forcing GetHeightForRow to be called again by calling ReloadRows instead.
You may or may not have to specify begin/end updates (this might just be for animation, though?)
tableView.BeginUpdates();
tableView.EndUpdates();