I used to use static UITableView but the table is too long and overflow the memory.
I switched a dynamic prototype UITableView with 1 type of cell, which has an UISwitch in it.
One of the cell, when turning on the switch, will turn off the switch of another cell. These cells have fixed index.
The IBAction method is in my UITableViewCell subclass and I don't want to add the UITableView as a property in my UITableViewCell.
How do I achieve the above effect?
I'm planing to use an id or similar to distinguish between the cells as each cell's switch has different effects, that doesn't solve the above requirement.
Thanks,
I would add a block property to your cell which you can use to notify your controller of changes in the switch. See my answer below to a question on this:
How can I get index path of cell on switch change event in section based table view
All your logic can now be implemented in the view controller.
You are best to create a data model in the view controller which the cells simply provide views and controls onto. When you flick one switch and the block fires, update the data model and simply reload the table. Any cells affected will show the new data model positions for their switches. Avoid using one cell to adjust another. Just update the model and reload the cells.
Related
Is it possible to make changes to a particular UITableViewCell? For example, change the text in one cell of a table view with a button click?
It's possible, but you should not do that.
As you said in your comment, you can ask the table view for a cell and then make changes to that cell, but don't do that.
You should do what HHumorous said, and change your data model, then tell the table view to reload the affected cell.
If you simply change the appearance of the cell, then when the user scrolls that cell off-screen and then back on-screen the changes will be lost.
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 have another question open where I'm trying to figure out how to reload the collectionView without auto-scrolling. I was also realizing there are a lot of other situations where I will need to change things in the collection view. Also I have some items that I will want to change the .alpha on and change the text of. Is there a way to do all of this in Swift? For example (to be specific) if I have a collection view with a view in each cell and that view has a textField in it, can I change the alpha and text, (change alpha with animation even) without reloading entire table?
Look at the documentation for UICollectionView. There are several "reload" methods:
reloadData()
reloadSections(_:)
reloadItems(at:)
If you just want to reload a single item, update your data source's data and then call reloadItems(at:) passing in the index path for the item.
Another option, if a cell is currently visible, is to use the cellForItem(at:) method to get a reference to an existing cell. Then you can directly access UI components of the cell as needed. You should also update your data model as needed so if the user scrolls and comes back, the cell will be rendered properly.
Most appropriate where you can update your custom view of a particular UIcollectionViewcell is reloadItemsAtIndexPaths.
You would be handling a particular item than whole collectionview with reloadData.
You can handle it via notifications or some call backs in your code where you can make decision when to update which cell.
Hope it will help you.
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 have several UITableViews, with different datasources in a iPad screen.
I need to copy/move a cell from the first tableView to the second, similar how is done with ListBox in other languages.
Now, I can reorder the cells, but the movement is restricted to the tableView. I want to drag the cell in tableView1 & drop in tableView2.
P.D. I'm open to use any other control to archive this. I take a look at AQGridView & DTGridView, however the layout is based in columns with different #items. If I can emulate columns with this controls or other then I can accept the workaround.
UPDATE:
I hope this links could help:
Observing pinch multi-touch gestures in a UITableView
This is the most close answer:
Drag and drop between two tables in ipad
I know how get a image from a view, I can detect the drag with a Gesture Recognizers, so I have all the setup in place but have not expertise in graphic development, so don't know how put this in motion...
This is definitely a very interesting question, and I wish I had the time to put together some test code to see if the idea I'm about to outline would actually work. My hope is that this will at least point you in the right direction.
UITableViewCell is a subclass of UIView, so I would create a subclass of UITableViewCell called something like DraggableTableViewCell so we can handle the touch events and then perform the following steps:
Create an instance of DraggableTableViewCell and configure it to appear like the selected cell.
Add the new cell as a subview of a view that is a common superview to both tables at the same location as the original cell.
Update the data source for the source table view and remove the original cell from the table view using deleteRowsAtIndexPaths:withRowAnimation:
Move the cell on the display by responding to touchesMoved:withEvent:
When touchesEnded:withEvent: is received, verify the cell is somewhat close to the other table view and determine the index path where to insert the new cell
Update the data source for the destination table view and call insertRowsAtIndexPaths:withRowAnimation:
Remove your draggable cell from its superview with a nice animation.
This entire process will need to be orchestrated by the view controller that controls the various table views on the screen.