[英]Saving multiple images to Parse
因此,出於演示目的,我從xcassets中訪問了一系列圖像。 我正在嘗試使用解析框架一次將150張圖像保存到解析服務器。 這是我到目前為止的代碼。 我的問題是我的應用程序cpu在測試中達到100%並下降為0。而且圖像沒有保存以進行解析。 我希望有人可以幫助我找到一種有效的方法來保存150張圖像進行解析。
var imageNameList: [String] {
var imageNameList2:[String] = [] //[NSMutableArray]()
for i in 0...149 {
let imageName = String(format: "pic_%03d", Int(i))
imageNameList2.append(imageName)
}
return imageNameList2
}
@IBAction func Continue(_ sender: Any) {
for imageName in imageNameList {
var objectForSave:PFObject = PFObject(className: "Clo")
let object:UIImage = UIImage(named: imageName)!
let tilesPF = imageNameList.map({ name in
let data = UIImagePNGRepresentation(object as! UIImage)!
let file = PFFile(data: data)
let tile = PFObject(className: "Tile")
tile["tile"] = file
})
objectForSave["tiles"] = tilesPF
objectForSave.saveInBackground(block: { responseObject, error in
//you'll want to save the object ID of the PFObject if you want to retrieve a specific image later
})
}
}
問題在於緊密的for循環同時啟動所有這些請求,從而導致http堆棧的某些部分成為瓶頸。
而是按以下順序運行請求(以我最接近Swift的方式)...
func doOne(imageName: String, completion: (success: Bool)->()) {
var objectForSave:PFObject = PFObject(className: "Clo")
let object:UIImage = UIImage(named: imageName)!
// ... OP code that forms the request
objectForSave.saveInBackground(block: { responseObject, error in
success(error == nil)
})
}
func doMany(imageNames: Array<String>, completion: (success: Bool)->()) {
if (imageNames.count == 0) return completion(YES)
let nextName = imageNames[0];
self.doOne(imageName:imageNames[0] completion: {(success: Bool) -> Void in
if (success) {
let remainingNames = imageNames[1..imageNames.count-1]
self.doMany(imageNames: remainingNames completion:completion)
} else {
completion(NO)
})
}
用英語講,以防萬一我弄錯了Swift,這個想法是通過完成處理程序將單個請求分解成它自己的函數。 構建第二個函數,該函數接受網絡請求的參數數組,並像待辦事項列表一樣使用該數組:完成列表中的第一項,完成后,遞歸調用自身以執行其余項。
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