i have created scrollview and have loaded tableview on that programmatically .also i have created customize tableview cell and displaying data in tableview.But my problem is whenever i am scrolling tableview vertically my data is not getting persist and data of cell is getting erase.Please help me how shuld i store that data
It sounds as if you might not be using the reuseidentifiers of the table view properly. If you give all cells the same reuseidentifier then as you scroll the cells that go off screen might end up losing the customizations you made to them. I suggest getting a good understanding of reuseidentifiers, you could start here:iphone-what-are-reuseidentifiers-uitableviewcell
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I'm using xcode 7 swift 2
in my app extension(TodayWidget extension) i'v put 2 table views that store the calculating results.......
2 TableViews
and its work fine, even if i scroll TodayWidget/notification view UP and DOWN again the data is there
Data
BUT sometimes after i scroll TodayWidget/notification view UP and DOWN again all data is lost and reset values to 0 again !!???
how i can prevent that from happening .....!!!
The table view have to reset the data in table view cells automatically. that's how it works. while scrolling, as soon as the cell becomes invisible it will be taked to be reused for other indexpath.
To achieve what you want in quite simple. You just need to have a dataSource to save your data in so you will not lose it while scrolling.
If you share some of your code I'll be able to give you more details how to solve this problem.
I have a dynamically created tableView in XCode which generates cells from an array. Currently, the cells do not fill the entire screen, that's to say that there are empty rows beneath them. How do I get them to fill any screen size for any iOS device at any orientation, please? Also, in another tableview, more array items populate the table - but then I can't scroll to view them all. How do I enable scrolling in a tableview?
So, in summary, how can I get my populated cells to fill the screen of any iOS device? And, how do I enable scrolling?
Thank you very much :) I really need help!
I am unsure of what you are asking because you haven't supplied enough information to determine exactly what task you are attempting to complete. Can you be more specific about what you are trying to do?
I can advise on your request for how to scroll, though. If you want to scroll, you'll have to nest the TableView as a child of a parent ScrollView. You can enable scrolling in the ScrollView, which will then allow you to scroll through the content in the child TableView.
I have a tableview with imageviews and textviews in each cell. When my view is loaded one of the textviews is invisible. But when I start scrolling the textview appears, so that my view looks as it is supposed to look. Does anyone know why this is happening?
P.S. I have read about reusing cells when scrolling so I have been very careful to construct my cells correctly.
Without code, no one can give you a exact answer. But for a guess....
Is your data is getting populated after your table call cellForRowAtIndexPath? When the cell populates the first time, no data, so the cell is in it's unformatted state. By the time you can interact with the table and scroll it off and on screen (which calls cellForRowAtIndexPath again), the data has been populated and so the cell looks as expected.
You can test this by putting a breakpoint in your cellForRowAtIndexPath method and check to see if your data objects are initialized or still set to nil.
I use tableView with custom cells and for cell drawing I use drawRect: method for scrolling performance. In edit mode when I move cells move and down sometimes some cells appear blank. And during scrolling also random cells start appear blank.Please look attached images. Can someone help to understand problem?
if you are using dequeueReusableCellForIdentifier then try removing that.
I mean to say alloc a new cell every time.
I am suggesting above based on assumption that your cell contains some heavy data which takes time in drawing. In this case if you reuse cell then it will take cell that goes out of visible screen and will paint draw new data in it.
If this doesn't help then please post some code showing how you are creating custom cell.
I have a UI Table View Controller. Each Cell Loads an image from my webserver.
If I scroll the TableView so that a particular cell scrolls out of view and then scroll back again the image for that cell has vanished and I have to wait for it to reload.
I'm guessing this is some performance/ memory management thing build into iphone?
How can I stop this behaviour?
I believe the cells in the tableview are recycled.
cache the images in memory and assign from your cache rather than loading the images directly into the tableview
I don't know if this is best practice or not but I think you could use an NSArray or NSDictionary of UIImage and load into there first and just assign references to the objects in the array.
Update
There is some code here which uses an NSMutableDictionary for the cache