ios - 如何在 Collection View 单元格中插入图像

Question

我想在 Collection View 单元格中插入三张图片，3 张图片。每个单元格一张图像。只有一个部分。 但是当模拟器显示黑屏时，没有任何图像。 这是我的部分代码:

import Foundation
import UIKit

class CatImagesViewController:UIViewController,UICollectionViewDataSource,UICollectionViewDelegate
{
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
    return 1
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

    return 3
}

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

    let con = CatService(test:"test")

    let temp = NSUserDefaults()
    let  number = temp.integerForKey("num_of_images")

    var title_array:Array<String> = con.imageNamesForCategoryAtIndex(number)

    var string:String = title_array[indexPath.row]

    print("indexPath.row \(indexPath.row)");
    print("string is \(string)")

    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("firstCollectionCell", forIndexPath: indexPath)

    let imageview:UIImageView=UIImageView(frame: CGRectMake(50, 50, self.view.frame.width-200, 50))
    let image:UIImage = UIImage(named:string)!
    imageview.image = image
   // self.view.addSubview(imageview)
    cell.contentView.addSubview(imageview)
    return cell
}
}

修改了cell.contentView.addSubview(image view)，还是黑屏

Answer 1

你应该使用

cell.contentView.addSubview(imageview)

indexPath.row 用于获知单元格在表格中的位置。

设置高度:

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    return CGSizeMake(50, 414)
}

你应该使用 NSIndexPath 的属性项

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

let con = CatService(test:"test")

let temp = NSUserDefaults()
let  number = temp.integerForKey("num_of_images")

var title_array:Array<String> = con.imageNamesForCategoryAtIndex(number)

var string:String = title_array[indexPath.item]

print("indexPath.row \(indexPath.item)");
print("string is \(string)")

let cell = collectionView.dequeueReusableCellWithReuseIdentifier("firstCollectionCell", forIndexPath: indexPath)

let imageview:UIImageView=UIImageView(frame: CGRectMake(50, 0, self.view.frame.width-200, 50))
let image:UIImage = UIImage(named:string)!
imageview.image = image
cell.contentView.addSubview(imageview)
return cell
}