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POUITableView's reloadRowsAtIndexPaths: seems to break insertRowsAtIndexPaths:
 

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  1. POUITableView's reloadRowsAtIndexPaths: seems to break insertRowsAtIndexPaths:
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    <p>I have a <code>UITableView</code> into which the user can insert new rows. When this happens, I want to reload all of the old rows in the table. One solution would be to just call <code>reloadData</code> as soon as the insertion takes place, which totally works, but this means I don't get the insertion animation.</p> <p>So when the user hits the "add row" button, I call <code>reloadRowsAtIndexPaths:</code> with every index path except the one just inserted. Then I call <code>insertRowsAtIndexPaths:</code> with only the newly inserted row. Reasonable, right?</p> <p>This causes the app to crash with the following explanation:</p> <blockquote> <p>Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (1) must be equal to the number of rows contained in that section before the update (0), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).</p> </blockquote> <p>This happens, as you can see in this example, even when <code>reloadRowsAtIndexPaths</code> is passed an empty array of index paths.</p> <p>Ah! I need to wrap the two calls with <code>beginUpdates</code> and <code>endUpdates</code>. Fair enough. But now the animation is completely broken.</p> <p>I'm performing the reload with a <code>UITableViewRowAnimationFade</code> and the insertion with a <code>UITableViewRowAnimationAutomatic</code>. But during the animation, the heights of every row changes, creating this weird flickery effect that looks just terrible. What's the correct way to animate these changes?</p> <h2>Edit:</h2> <p>From the docs for <code>reloadRowsAtIndexPaths:withRowAnimation:</code>:</p> <blockquote> <p>Reloading a row causes the table view to ask its data source for a new cell for that row. The table animates that new cell in as it animates the old row out. Call this method if you want to alert the user that the value of a cell is changing. If, however, notifying the user is not important—that is, you just want to change the value that a cell is displaying—you can get the cell for a particular row and set its new value.</p> </blockquote> <p>I think that, in my application, manually updating each cell is the right way to go. However, I am still perturbed by this bizarre animation bug, and would like to know what the cause of it is / what I would do if I did "want to alert the user that the value of the cell is changing."</p>
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    1. COWhy do you need to reload the existing rows, can't you just have the insertRows... statement? Do the existing rows change their values?
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    2. COYes, when a new row is added the values displayed in all the other rows change. Otherwise I wouldn't be reloading them.
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    3. COAnd the height thing - are your cells different heights, or different in height to the value specified in your table?
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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