以下是我的代码：
var food = [chicken, fish, duck, pork]
var recipeNames = [String]()
var recipePictures = [UIImage]()
func getRecipes() {
let getRecipesQuery = PFQuery(className: "recipes")
getRecipesQuery.whereKey("food", containedIn: food)
getRecipesQuery.findObjectsInBackgroundWithBlock { (recipes, error) -> Void in
if let recipes = recipes {
self.recipeNames.removeAll(keepCapacity: true)
self.recipePictures.removeAll(keepCapacity: true)
for recipe in recipes {
self.recipeNames.append(recipe["name"] as! String)
if let recipePictureFile = recipe["pictureFile"] as? PFFile {
recipePictureFile.getDataInBackgroundWithBlock({ (imageData, error) -> Void in
if error == nil {
if let picture = UIImage(data: imageData!) {
self.recipePictures.append(picture)
}
}
})
}
}
}
print(self.recipeNames.count)
print(self.recipePictures.count)
}
}
我在末尾打印了两个数组计数以检查是否有任何提取，计数都是0.任何想法为什么会发生这种情况？课堂上肯定有一些关键词＆＃34; food＆＃34;等于＆＃34;食物中的一个物体＆＃34;阵列，谢谢！
修改
func getRecipes() {
let getRecipesQuery = PFQuery(className: "recipes")
getRecipesQuery.whereKey("food", containedIn: food)
getRecipesQuery.findObjectsInBackgroundWithBlock { (recipes, error) -> Void in
if let recipes = recipes {
self.recipeNames.removeAll(keepCapacity: true)
self.recipePictures.removeAll(keepCapacity: true)
for recipe in recipes {
self.recipeNames.append(recipe["name"] as! String)
if let recipePictureFile = recipe["pictureFile"] as? PFFile {
recipePictureFile.getDataInBackgroundWithBlock({ (imageData, error) -> Void in
if error == nil {
if let picture = UIImage(data: imageData!) {
self.recipePictures.append(picture)
}
}
})
}
}
dispatch_async(dispatch_get_main_queue()) {
self.recipesTableView.reloadData()
}
}
}
}