blocks|key|2051576|text|很简单，真的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2051577|UITableViewDelegate有这样的方法：|2051578|tableView:targetIndexPathForMoveFromRowAtIndexPath:toProposedIndexPath:|code-block|syntax|javascript|2051579|当用户将鼠标悬停在可能的下拉点上时，将调用此函数。你有机会说，“不！不要把它扔在那里！把它扔到这里来。”您可以将不同的索引路径返回到建议的索引路径。|2051580|我所做的就是检查部分索引是否匹配。如果它们这样做了，那么很好，返回建议的路径。如果不是，则返回源路径。这也很好地防止了其他部分中的行甚至在您拖动时移动-并且当您尝试将其移动到另一个部分时，被拖动的行将捕捉回其原始位置。|2051581|-+(NSIndexPath+*)tableView:(UITableView+*)tableView+targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath+*)sourceIndexPath+toProposedIndexPath:(NSIndexPath+*)proposedDestinationIndexPath
{
++++if(+sourceIndexPath.section+!=+proposedDestinationIndexPath.section+)
++++{
++++++++return+sourceIndexPath;
++++}
++++else
++++{
++++++++return+proposedDestinationIndexPath;
++++}
}|2051582|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|V|8|@]|9|@]|A|$G|H]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Simple enough, really.

The UITableViewDelegate has the method:

<pre><code>
tableView:targetIndexPathForMoveFromRowAtIndexPath:toProposedIndexPath:
</code></pre>

This gets called while the user is hovering over a potential drop point.
You get a chance to say, "no! don't drop it there! Drop it over here instead". You can return a different index path to the proposed one.

All I did was check if the section indices match. If they do then great, return the proposed path. if not, return the source path.
This also nicely prevents the rows in other sections even moving out of the way as you drag - and the dragged row will snap back to it's original position of you try to move it to another section.

<pre><code>
- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath
{
 if( sourceIndexPath.section != proposedDestinationIndexPath.section )
 {
 return sourceIndexPath;
 }
 else
 {
 return proposedDestinationIndexPath;
 }
}
</code></pre>

blocks|key|1837487|text|此实现将防止在原始节之外进行重新排序(如Phil的回答)，但它也会将记录捕捉到节的第一行或最后一行，这取决于拖动的位置，而不是开始的位置。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1837488|-+(NSIndexPath+*)tableView:(UITableView+*)tableView+targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath+*)sourceIndexPath+toProposedIndexPath:(NSIndexPath+*)proposedDestinationIndexPath
{
++if+(sourceIndexPath.section+!=+proposedDestinationIndexPath.section)+{
++++NSInteger+row+=+0;
++++if+(sourceIndexPath.section+<+proposedDestinationIndexPath.section)+{
++++++row+=+[tableView+numberOfRowsInSection:sourceIndexPath.section]+-+1;
++++}
++++return+[NSIndexPath+indexPathForRow:row+inSection:sourceIndexPath.section];+++++
++}

++return+proposedDestinationIndexPath;
}|code-block|syntax|javascript|1837489|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This implementation will prevent re-ordering outside of the original section like Phil's answer, but it will also snap the record to the first or last row of the section, depending on where the drag went, instead of where it started.

<pre><code>- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath
{
 if (sourceIndexPath.section != proposedDestinationIndexPath.section) {
 NSInteger row = 0;
 if (sourceIndexPath.section &lt; proposedDestinationIndexPath.section) {
 row = [tableView numberOfRowsInSection:sourceIndexPath.section] - 1;
 }
 return [NSIndexPath indexPathForRow:row inSection:sourceIndexPath.section]; 
 }

 return proposedDestinationIndexPath;
}
</code></pre>

blocks|key|1837528|text|而不是@Jason+Harwig，下面的代码工作正常。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1837529|-+(NSIndexPath+*)tableView:(UITableView+*)tableView+targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath+*)sourceIndexPath+toProposedIndexPath:(NSIndexPath+*)proposedDestinationIndexPath
++++{
++++++if+(sourceIndexPath.section+!=+proposedDestinationIndexPath.section)+{
++++++++NSInteger+row+=+0;
++++++++if+(sourceIndexPath.section+<+proposedDestinationIndexPath.section)+{
++++++++++row+=+[tableView+numberOfRowsInSection:sourceIndexPath.section]+-+1;
++++++++}
++++++++return+[NSIndexPath+indexPathForRow:row+inSection:sourceIndexPath.section];+++++
++++++}

++++++return+proposedDestinationIndexPath;
++++}|code-block|syntax|javascript|1837530|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Than @Jason Harwig, the code below works correctly.

<pre><code>- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath
 {
 if (sourceIndexPath.section != proposedDestinationIndexPath.section) {
 NSInteger row = 0;
 if (sourceIndexPath.section &lt; proposedDestinationIndexPath.section) {
 row = [tableView numberOfRowsInSection:sourceIndexPath.section] - 1;
 }
 return [NSIndexPath indexPathForRow:row inSection:sourceIndexPath.section]; 
 }

 return proposedDestinationIndexPath;
 }
</code></pre>

blocks|key|2051702|text|您可以使用下面的方法防止在节间移动行。只是不允许在两节之间有任何移动。您甚至可以控制某一节中特定行的移动。例如，节中的最后一行。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2051703|示例如下：|2051704|-+(NSIndexPath+*)tableView:(UITableView+*)tableView+targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath+*)sourceIndexPath+toProposedIndexPath:(NSIndexPath+*)proposedDestinationIndexPath+{

++++//+Do+not+allow+any+movement+between+section
++++if+(+sourceIndexPath.section+!=+proposedDestinationIndexPath.section)+{
++++++++return+sourceIndexPath;
++++}
++++//+You+can+even+control+the+movement+of+specific+row+within+a+section.+e.g+last+row+in+a+++++Section

++++//+Check+if+we+have+selected+the+last+row+in+section
++++if+(sourceIndexPath.row+<+sourceIndexPath.length)+{
++++++++return+proposedDestinationIndexPath;
++++}+
++++else+{
++++++++return+sourceIndexPath;
++++}
}|code-block|syntax|javascript|2051705|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

You can prevent the movement of rows in between section using below method.
Just do not allow any movement in between section.
You can even control the movement of specific row within a section. e.g last row in a Section.

Here is the example:

<pre><code>- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath {

 // Do not allow any movement between section
 if ( sourceIndexPath.section != proposedDestinationIndexPath.section) {
 return sourceIndexPath;
 }
 // You can even control the movement of specific row within a section. e.g last row in a Section

 // Check if we have selected the last row in section
 if (sourceIndexPath.row &lt; sourceIndexPath.length) {
 return proposedDestinationIndexPath;
 } 
 else {
 return sourceIndexPath;
 }
}
</code></pre>

I was hitting my head over this one, and google was turning up nothing.
I eventually worked it out and thought I'd write it up here for the sake of the next person.

You have a <code>UITableView</code> with multiple sections. Each section is homogeneous, but the table overall is heterogeneous. So you might want to allow re-ordering of rows within a section, but not across sections. Maybe you only even want want one section to be reorderable at all (that was my case).
If you're looking, as I was, at the <code>UITableViewDataSourceDelegate</code> you won't find a notification for when it is about to let you move a row between sections. You get one when it starts moving a row (which is fine) and one when it's already moved it and you get a chance to sync with your internal stuff. Not helpful.

So how can you prevent re-orders between sections?

I'll post what I did as a separate answer, leaving it open for someone else to post an even better answer!

How to limit UITableView row reordering to a section

数据同步

我在这个问题上撞到了头，谷歌却什么也没找到。我最终解决了它，并认为我应该把它写在这里，为了下一个人。您有一个包含多个部分的UITableView。每个部分都是同构的，但表整体上是不同的。因此，您可能希望允许在一个区段内重新排序行，但不允许跨区段重新排序。也许你甚至只想要一个部分是可重新排序的(这就是我的情况)。如果您像...

问如何将UITableView行重排序限制为一个节
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