UICollectionView 在 IB 中不包含 UICollectionViewCell [英] UICollectionView doesn't contain UICollectionViewCell in IB

问题描述

我正在尝试将 UICollectionView 添加到 IB 中的 .nib 文件中.我已经完成了一些教程并且没有遇到任何问题.

I'm trying to add a UICollectionView to a .nib file in IB. I've worked through a few tutorials and had no problems.

在我现有的应用程序中，当我将集合视图拖到 IB 中的视图中然后展开对象时，CollectionView Flow Layout 在那里，但没有集合视图单元格.我也无法将单元格拖放到集合视图中.此外，集合视图的显示方式也有所不同，显示的是单元格网格的图像，而不是普通的白框.

In my existing app, when I drag a collection view into a view in IB and then expand the object, the CollectionView Flow Layout is there , but there is no collection view cell. I also cannot drag and drop a cell into the collection view. Also the collection view is displayed differently, showing an image of a grid of cells instead of the normal white box.

我尝试使用 nib 创建一个新的视图控制器，并且在添加 collectionView 时得到相同的结果.

I've tried creating a new view controller with nib, and have the same results when adding a collectionView.

此应用面向 iOS 4.2，但我已将部署目标更改为 iOS 6.

This app WAS targeting iOS 4.2, but I've changed the deployment target to iOS 6.

在任何新创建的项目中，我都没有这种行为.

In any newly created projects I don't get this behavior.

推荐答案

我不能告诉你为什么它不起作用，但对我来说，这篇博文中的子类方法解决了这个问题:

I can't tell you why it does not work, but for me the subclass approach from this blog post solved the problem:

http://www.adoptioncurve.net/archives/2012/09/a-simple-uicollectionview-tutorial.php

这里有一个简短的总结:

here is a short summary:

• 创建一个扩展 UICollectionViewCell 的新类 MyViewCell 并根据需要创建属性、操作、出口和方法.

@interface MyViewCell : UICollectionViewCell

• 创建一个以 Collection View Cell 作为根对象的 View(xib 文件)(并删除默认创建的对象).
• 在属性中将此 Collection View Cell 的自定义类设置为您的扩展类 MyViewCell(而不是默认的 UICollectionViewCell).
• 在 Collection Reusable View 下的属性中定义一个标识符，例如myCell，您稍后将需要它来注册您的通话.

• 返回您的自定义类并修改 inithWithFrame 方法以加载和使用您创建的视图.

• create a View (xib file) with a Collection View Cell as its root object (and delete the object which is created by default).
• in the attributes set the custom class of this Collection View Cell to your extended class MyViewCell (instead of the default UICollectionViewCell).
• in the attributes under Collection Reusable View define an Identifier, e.g. myCell, you will need this later to register your call.

• go back to your custom class and modify the inithWithFrame method to load and use your created view.

- (id)initWithFrame:(CGRect)frame 
{ 
   self = [super initWithFrame:frame]; 
   if (self) 
   { 
     // Initialization code 
     NSArray *arrayOfViews = [[NSBundle mainBundle] loadNibNamed:@"CVCell" owner:self options:nil];

     if ([arrayOfViews count] < 1) { return nil; }

     if (![[arrayOfViews objectAtIndex:0] isKindOfClass:[UICollectionViewCell class]]) { return nil; }

     self = [arrayOfViews objectAtIndex:0];
   }
   return self;
}

然后你可以注册这个类供collectionView使用

then you can register this class to be used by the collectionView with

[self.collectionView registerClass:[MyViewCell class] forCellWithReuseIdentifier:@"myCell"];

这篇关于UICollectionView 在 IB 中不包含 UICollectionViewCell的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！