編程設置UICollectionViewCell作爲選擇，但indexPathsForSelectedItems.count是0

Question

我編程設置了一個名爲CheckCell要選擇定製UICollectionViewCell如下：

[self.myCollectionView cellForItemAtIndexPath:indexPath] setSelected:YES]; 

if ([[self.myCollectionView cellForItemAtIndexPath:indexPath] isSelected]) { 
    NSLog(@"Selected"); 
} 

NSLog(@"%i",[self.myCollectionView indexPathsForSelectedItems].count); 

「選定」第一個NSLog的打印導致我相信，在細胞確實選擇了IndexPath。但是，第二個NSLog的結果是0.爲什麼選擇的單元格索引沒有被添加到indexPathsForSelectedItems？

Answer 1

這是答案。

呼叫的selectItemAtIndexPath代替[self.myCollectionView cellForItemAtIndexPath:indexPath] setSelected:YES];

例如代碼：

NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0] ; 

[self.collectionView selectItemAtIndexPath:indexPath animated:YES scrollPosition:UICollectionViewScrollPositionNone]; 

if ([[self.collectionView cellForItemAtIndexPath:indexPath] isSelected]) { 

    NSLog(@"selected count %i",[self.collectionView indexPathsForSelectedItems].count); 
} 

輸出

selected count 1