我正在尝试将网址中的图片提取到我的收藏视图中。可显示的图像数量取决于阵列数量。
这是我的代码:
class CollectionViewController: UICollectionViewController {
@IBOutlet weak var searchBox: UITextField!
var imageArray:[String] = []
override func viewDidLoad() {
super.viewDidLoad()
}
let link = "https://www.googleapis.com/my_link_is_here"
guard let url = URL(string: link) else {
print("Error: cannot create URL")
return
}
let request = URLRequest(url: url)
URLSession.shared.dataTask(with: request) { data, response, error in
guard error == nil else {
print("error calling GET on /todos/1")
print(error!)
return
}
do{
guard let json = try JSONSerialization.jsonObject(with: data!, options: []) as? [String : Any] else {
print("\(error?.localizedDescription)")
return
}
//print("The todo is: " + json.description)
guard let todotitle = json["items"] as? [Any] else {
print("Could not get todo title from JSON")
return
}
let arrcnt = todotitle.count
var i = 0
while (i < arrcnt){
guard let todotitle1 = todotitle[i] as? [String: Any] else {
print("Could not get todo title1 from JSON")
return
}
guard let todotitle2 = todotitle1["image"] as? [String : Any] else {
print("Could not get todo title2 from JSON")
return
}
guard let todotitle3 = todotitle2["thumbnailLink"] as? String else {
// continue
print("Could not get todo title3 from JSON")
return
}
self.imageArray.append(todotitle3)
print(self.imageArray)
i += 1
}
}catch{
print("error trying to convert data to JSON")
return
}
}.resume()
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
// MARK: UICollectionViewDataSource
override func numberOfSections(in collectionView: UICollectionView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of items
return self.imageArray.count
}
问题是当我写&#34;返回self.imageArray.count&#34;它返回零。它采用数组的初始化值为空数组。如何在追加最终数组之后对其进行计数。
答案 0 :(得分:0)
您需要在collectionView
循环后在主线程上重新加载while
。另外,您可以通过单个guard
语句而不是多个语句来减少代码,并使用for循环而不是while,因此整个代码将是这样的。
do{
guard let json = try JSONSerialization.jsonObject(with: data!, options: []) as? [String : Any] else {
print("\(error?.localizedDescription)")
return
}
//print("The todo is: " + json.description)
guard let array = json["items"] as? [[String : Any]] else {
print("Could not get todo title from JSON")
return
}
for dic in array {
guard let imageDic = dic["image"] as? [String : Any], let thumbnailLink = imageDic["thumbnailLink"] as? String else {
print("Could not get thumbnailLink")
return
}
self.imageArray.append(thumbnailLink)
}
//Now you need to reload the collectionView on main thread.
DispatchQueue.main.async {
self.collectionView.reloadData()
}
}