我正在使用ARKit,我无法从SCNScene网址获取下载进度。这是我的代码:
func downloadModel(hitTestResult: ARHitTestResult) {
DispatchQueue.global().async {
// create loading view
// I WANT TO GET DOWNLOAD PROGRESS HERE
let loading = UIAlertController(title: nil, message: "Please wait...\(downloadProgressValueHere)%", preferredStyle: .alert)
let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
loadingIndicator.startAnimating();
loading.view.addSubview(loadingIndicator)
self.present(loading, animated: true, completion: nil)
// download 3d model from server
let myURL = URL(string: "http://www.mydownloadlink.com")
let scene = try! SCNScene(url: myURL!, options: nil)
let node = (scene.rootNode.childNode(withName: "parentNode", recursively: true))!
self.sceneView.scene.rootNode.addChildNode(node)
// dismiss loading view
loading.dismiss(animated: true, completion: nil)
}
}
如何将下载进度转到“请稍候...”消息?谢谢大家。
答案 0 :(得分:1)
我的理解是,虽然看起来以下方法实际上会采用远程URL但它不会(尽管我可能错了):
convenience init(url: URL,
options: [SCNSceneSource.LoadingOption : Any]? = nil) throws
无论如何回答你的问题是你的一个例子(这可能有点OTT,但希望它也能帮助其他人)。
让我们说明SCNScene
以下的URL
文件:
http://stackOverflow.com/stackOverFlow.scn
首先,我们需要为ProgressInfo
创建变量,如下所示:
var loading: UIAlertController!
var loadingIndicator: UIActivityIndicatorView!
var downloadString: String = "Downloading"
然后我们要做的是创建一个URLSession来下载文件,如下所示:
/// Downloads An SCNFile From A Remote URL
func downloadSceneTask(){
//1. Get The URL Of The SCN File
guard let url = URL(string: "http://stackOverflow.com/stackOverFlow.scn") else { return }
//2. Create The Download Session
let downloadSession = URLSession(configuration: URLSession.shared.configuration, delegate: self, delegateQueue: nil)
//3. Create The Download Task & Run It
let downloadTask = downloadSession.downloadTask(with: url)
downloadTask.resume()
//4. Show The Progress Alert
DispatchQueue.main.async {
self.loading = UIAlertController(title: nil, message: self.downloadString , preferredStyle: .alert)
let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
loadingIndicator.startAnimating();
self.loading.view.addSubview(loadingIndicator)
self.present(self.loading, animated: true, completion: nil)
}
}
请注意,我创建的variable
导致downloadString
我们稍后会更改。
然后我们将引用以下URLSession Delegates,例如:
class ViewController: UIViewController, URLSessionDelegate, URLSessionDownloadDelegate {
}
我们的示例将调用以下函数:
第一个跟踪我们下载的进度,您可以在HUD
或使用progressIndicator
显示进度的内容:
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask,
didWriteData bytesWritten: Int64,
totalBytesWritten: Int64,
totalBytesExpectedToWrite: Int64) {
print("Downloaded \(totalBytesWritten) / Of \(totalBytesExpectedToWrite) Bytes")
DispatchQueue.main.async {
self.loading.message = "Downloaded \(totalBytesWritten) / Of \(totalBytesExpectedToWrite) Bytes"
}
}
第二个处理文件下载的时间:
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
//1. Remove The Loading View
loading.dismiss(animated: true, completion: nil)
//2. Create The Filename
let fileURL = getDocumentsDirectory().appendingPathComponent("stackOverFlow.scn")
//3. Copy It To The Documents Directory
do {
try FileManager.default.copyItem(at: location, to: fileURL)
print("Successfuly Saved File \(fileURL)")
//4. Load The Model
loadModel()
} catch {
print("Error Saving: \(error)")
}
}
请注意,在此方法中,我使用以下函数检索并将下载的文件复制到documents directory
:
/// Returns The Documents Directory
///
/// - Returns: URL
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
return documentsDirectory
}
一旦文件被下载并复制到我们之后,我们就会(4)像我们一样打电话给loadModel function
:
/// Loads The SCNFile From The Documents Directory
func loadModel(){
//1. Get The Path Of The Downloaded File
let downloadedScenePath = getDocumentsDirectory().appendingPathComponent("stackOverFlow.scn")
do {
//2. Load The Scene Remembering The Init Takes ONLY A Local URL
let modelScene = try SCNScene(url: downloadedScenePath, options: nil)
//3. Create A Node To Hold All The Content
let modelHolderNode = SCNNode()
//4. Get All The Nodes From The SCNFile
let nodeArray = modelScene.rootNode.childNodes
//5. Add Them To The Holder Node
for childNode in nodeArray {
modelHolderNode.addChildNode(childNode as SCNNode)
}
//6. Set The Position
modelHolderNode.position = SCNVector3(0, 0, -1.5)
//7. Add It To The Scene
self.augmentedRealityView?.scene.rootNode.addChildNode(modelHolderNode)
} catch {
print("Error Loading Scene")
}
}
请注意,这是一个非常粗略的例子,并不包括检查文件是否存在,缩放等等,但它应该足以帮助您实现所需的...