UITableView: load all cells

load all cells in uitableview before scrolling
indexpathsforvisiblerows
uitableview lazy loading
uitableviewdatasourceprefetching
ios uitableview lazy loading data
uitableview load data asynchronously
uitableviewcell reuse problem swift
uicollectionview prefetch data source example

Is it possible to load all cells of an UITableView when the view is loaded so that they are not loaded when I'm scrolling? (I would show a loading screen while doing this)

Please, it's the only way at my project (sorry too complicate to explain why ^^)

EDIT:

Okay let me explain you, what I'm definite doing:

- (UITableViewCell *)tableView:(UITableView *)tableView
     cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
   NSString *cellIdentifier = [NSString stringWithFormat:@"Identifier %i/%i", indexPath.row, indexPath.section];
   CustomTableCell *cell = (CustomTableCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
   NSDictionary *currentReading;

   if (cell == nil)
   {
       cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];

       UILabel *label;
       UIView *separator;

       if(indexPath.row == 0)
       {
           // Here I'm creating the title bar of my "table" for each section
       }
       else
       {
           int iPr = 1;

           do
           {
               currentReading = [listData objectAtIndex:iPr-1];
               iPr++;
           } while (![[currentReading valueForKey:@"DeviceNo"] isEqualToString:[devicesArr objectAtIndex:indexPath.section]] || 
                      [readingresultsArr containsObject:[currentReading valueForKey:@"ReadingResultId"]]);

           [readingresultsArr addObject:[currentReading valueForKey:@"ReadingResultId"]];
           //
           // ...
           //
       }
    }
    return cell;
}

My error happens in the do-while-loop: "listData" is an array with multiple dictionaries in it. My problem ist that when I’m scrolling my table slowly down, all is fine, but when I’m scrolling quickly to the end of the view and then I’m scrolling to the middle, I get the error that iPr is out of the array’s range. So the problem is, that the last row of the first section has already been added to the "readingresultsArr", but has not been loaded or wants to be loaded again. That’s the reason why I want to load all cells at once.

You can cause all of the cells to be pre-allocated simply by calling:

[self tableView: self.tableView cellForRowAtIndexPath: indexPath];

for every row in your table. Put the above line in an appropriate for-loop and execute this code in viewDidAppear.

The problem however is that the tableView will not retain all of these cells. It will discard them when they are not needed.

You can get around that problem by adding an NSMutableArray to your UIViewController and then cache all the cells as they are created in cellForRowAtIndexPath. If there are dynamic updates (insertions/deletions) to your table over its lifetime, you will have to update the cache array as well.

Smoothen your table view data loading using , Every cell is half of the screen. There is an NSLog printing the loaded cell. As you can see, right now the project is only loading the visible cells. The standard cell configurations display a simple combination of text and images, but you can define custom cells that display any content you want. You can also supply header and footer views to provide additional information for groups of cells. Adding a Table View to Your Interface

put a uitableview on a uiscrollview

for example , you expect the height of the full list uitableview is 1000

then set the uiscrollview contentsize is 320X1000 and set the uitableview height is 1000

then all cell load their content even not visible in screen

Tutorial: How to preload cells of UITableView – Something About iOS, Create and configure cells for your table dynamically using a data source object, that adopts the UITableViewDataSourcePrefetching protocol—to begin loading that data With static tables, you specify all of your table's data up front in your� Arvindh Sukumar looks at how to create self sizing cells with UITableView and UICollectionView and Auto Layout in iOS 8 to allow for truly dynamic layouts.

in my case it was that I used automaticDimension for cells height and put estimatedRowHeight to small that is why tableview loaded all cells

Filling a Table with Data, (The Apple Watch is different). You do not need to 'load' all of the rows. You only need to respond to this method: -(UITableViewCell *) tableView:(UITableView� NOTE: This approach will usually result in the recreation of all new table cell instances. If this is something you feel strongly about, you may want to look into the batch updating features of a table. For more information, take a look at the following methods in UITableView:

Following the comment that was made by juancazalla, I found that if you have a tableView that is using automaticDimension, loading all the cells at once can be best achieved by setting estimatedRowHeight to a low value (such as 1).

large number of rows for uitableview, All the cells in a table view come from a prototype. In this way, you don't have to load into memory the full data, which might not even fit or be� The question is simple: How do you load custom UITableViewCell from Xib files? Doing so allows you to use Interface Builder to design your cells. The answer apparently is not simple due to memory

UITableview: The Essential Solution for Scrolling iOS Interfaces, I need to force UITableView to load all cells based on datasource and get resulting UITableView height before it will be displayed on UI. I have other logic to be� UITableView not displaying cells Tag: ios , uitableview , swift , xcode6 I am using Xcode 6 Swift and storyboards to build an IOS app. Bellow is what I have in my File.swift:

Force UITableView to load cells before it is displayed, This method is called every time a cell needs to be displayed. The faster it Only the when loading the table view the first time, by placing it in� The delay is probably loading the cells for the first time. Second time they are probably cached in ram somewhere. You could move the delay to load time by creating two cells in your app delegate on app load which would most likely populate any cache up front meaning your first usage would be as fast as the second. Related:

Smooth Scrolling in UITableView and UICollectionView, Dynamically loading new rows into a table. Oct 2, 2010 � 9 minute read. UITableViewController. A pattern that is common to many mobile apps is to allow the� A UITable View Cell object is a specialized type of view that manages the content of a single table row. You use cells primarily to organize and present your app’s custom content, but UITable View Cell provides some specific customizations to support table-related behaviors, including: Applying a selection or highlight color to the cell.

Comments
  • "Please, it's the only way at my project" - it certainly shouldn't be. And please explain, even if it's complicated. Apart from this not being possible, it's also terrible wrong parctice in terms of memory management.
  • @H2CO3 I've edited my question and described my problem in more detail. Hope you can help me.
  • Could you explain what you're trying to accomplish with the do...while loop? It looks like you're trying to find an object meeting some criteria, and then building up a new array on the fly out of that, but why do you need to do that there? Can you build that array before reloading the table?
  • This was the answer I was searching for :) You are my hero! Big thanks! But also thanks to the other ones for their help.
  • I originally said use an NSMutableArray, but NSDictionary would probably be better since you can use the indexPath.row as the key. NSMutableArray won't let you add things out of order.
  • Yes I have used NSDictionary with a string like "indexPath.row/indexPath.section" as key. But you brought me in the right direction, thanks :) PS: [self.tableView tableView: self.tableView cellForRowAtIndexPath: indexPath]; should be without the first ".tableView" in your answer
  • @Kent hey so im having the reverse problem. all my cells are being loaded into memory and cellforrowatindexpath is being called and im not calling it manually. why is this?
  • causing memory issue, cells are not getting the release from memory
  • Perfect recipe for troubles.
  • Thanks for this comment. Was wondering why a table view was always loading all of it's rows, yep, it is under a scroll view. Not sure why this is, but ok, have to rework the UI
  • @highmaintenance problem is not with the answer but with the question. this answer gets job done, need also to disable scroll of tableview.
  • Welcome to Stack Overflow. :-) Could you provide an example?
  • Please provide code snippet understand your answer more better way
  • What @Lina mentions is not a solution to the question, however, it's a very good trick if you need to preload some more cells than the one being rendered in the screen while using automaticDimension. This trick has been useful to me sometimes in which I have a tableview with some complex cells but I only have like 4 or 5 cells. If I set a low value for estimatedRowHeight, the tableview will preload all the cells since it expects them to be visible. After this, when I scroll to the bottom all the cells where already preloaded by the system. If use high values, it will feel laggy.