Getting DidReceiveMemoryWarning die ganze Zeit bei der Arbeit mit Bildern

Question

Anfügen des Quellcodes für die Anwendung, die ich erstellt habe, ist eine einfache Anwendung mit der Sammlungsansicht und Schaltfläche, um ein Bild aus der Galerie oder Kamera zu wählen. Die ios App stürzt ab, nachdem 8 Bilder kontinuierlich von der Kamera aufgenommen wurden.

using CoreGraphics; 
using Foundation; 
using System; 
using System.Collections.Generic; 
using System.Drawing; 
using System.Linq; 
using UIKit; 

namespace App2.iOS 
{ 
public class imagesDisplay 
{ 
public bool PlusImg; 
public bool uploaded; 
public string path { get; set; } 
public int id { get; set; } 

     public imagesDisplay(bool uploaded, bool PlusImg = false, string path = null, int id = 0) 
     { 
      this.uploaded = uploaded; 
      this.PlusImg = PlusImg; 
      this.path = path; 
      this.id = id; 
     } 
    } 
public partial class ViewController : UIViewController 
{ 

    public List<imagesDisplay> images = new List<imagesDisplay>(); 
    private UIAlertController alert; 
    private UIImagePickerController imagePicker; 
    private NSData imgData; 
    private NSData thumdata; 

    public ViewController (IntPtr handle) : base (handle) 
    { 
    } 

    public override void ViewDidLoad() 
    { 
     base.ViewDidLoad(); 
     imgCollection.SetCollectionViewLayout(new LineLayout(), false); 
     imgCollection.AllowsMultipleSelection = true; 
     imgCollection.RegisterNibForCell(UINib.FromName("imageceCollectionViewCell", null), imageceCollectionViewCell.Key); 
     alert = UIAlertController.Create("", "Select image from : ", UIAlertControllerStyle.ActionSheet); 

     var cameraaction = UIAlertAction.Create("Bruk kamera", UIAlertActionStyle.Default, a => 
     { 
      imagePicker = new UIImagePickerController(); 
      imagePicker.SourceType = UIImagePickerControllerSourceType.Camera; 
      imagePicker.FinishedPickingMedia += Handle_FinishedPickingMedia; 
      imagePicker.Canceled += Handle_Canceled; 
      imagePicker.AllowsImageEditing = false; 
      this.NavigationController.PresentViewController(imagePicker, true, null); 
     }); 
     alert.AddAction(cameraaction); 

     var galleryaction = UIAlertAction.Create("Last opp bilder", UIAlertActionStyle.Default, a => 
     { 
      imagePicker = new UIImagePickerController(); 
      imagePicker.SourceType = UIImagePickerControllerSourceType.PhotoLibrary; 
      imagePicker.FinishedPickingMedia += Handle_FinishedPickingMedia; 
      imagePicker.Canceled += Handle_Canceled; 
      imagePicker.AllowsImageEditing = false; 
      this.NavigationController.PresentViewController(imagePicker, true, null); 
     }); 
     alert.AddAction(galleryaction); 
     alert.AddAction(UIAlertAction.Create("Avbryt", UIAlertActionStyle.Cancel, a => { })); 
     imgCollection.Source = new ImageCollectionSource(images,new WeakReference<UINavigationController>(this.NavigationController)); 
    } 

    public override void DidReceiveMemoryWarning() 
    { 
     base.DidReceiveMemoryWarning(); 
     // Release any cached data, images, etc that aren't in use. 
    } 

    partial void UIButton125_TouchUpInside(UIButton sender) 
    {    
     this.PresentViewController(alert, true, null); 
    } 
    private void Handle_Canceled(object sender, EventArgs e) 
    { 
     imagePicker.DismissModalViewController(true); 
    } 

    private void Handle_FinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs e) 
    { 
     try 
     { 
      NSUrl referenceURL = e.Info[new NSString("UIImagePickerControllerReferenceUrl")] as NSUrl; 
      if (referenceURL != null) 
       Console.WriteLine("Url:" + referenceURL.ToString()); 
      UIImage originalImage = e.Info[UIImagePickerController.OriginalImage] as UIImage; 
      if (originalImage != null) 
      { 
       var documentsDirectory = Environment.GetFolderPath 
        (Environment.SpecialFolder.Personal); 
       string timestamp = DateTime.Now.ToString("yyyyMMddHHmmssffff"); 
       string jpgFilename = System.IO.Path.Combine(documentsDirectory, timestamp + ".jpg"); // hardcoded filename, overwritten each time 
       string thumname = System.IO.Path.Combine(documentsDirectory, timestamp + "_thumb" + ".jpg"); 
       imgData = originalImage.AsJPEG(); 
       Console.WriteLine("Original image size = " + imgData.Length); 
       thumdata = originalImage.AsJPEG(0.0f); 
       Console.WriteLine("after funtion compresion image size = " + thumdata.Length); 
       NSError err = null; 
       if (imgData.Save(jpgFilename, false, out err)) 
       { 
        Console.WriteLine("saved as " + jpgFilename); 
        NSError err1 = null; 
        if (thumdata.Save(thumname, false, out err1)) 
        { 
         Console.WriteLine("saved as " + jpgFilename); 
        } 
        else 
        { 
         Console.WriteLine("NOT saved as " + jpgFilename + " because" + err.LocalizedDescription); 
        } 
       } 
       else 
       { 
        Console.WriteLine("NOT saved as " + jpgFilename + " because" + err.LocalizedDescription); 
       } 
       images.Add(new imagesDisplay(false, false, thumname, 0)); 
      } 
      imgCollection.ReloadData(); 
      imagePicker.DismissViewController(true, null); 
     } 
     catch (Exception ex) 
     { 

     } 
    }   
} 
public class LineLayout : UICollectionViewFlowLayout 
{ 
    public LineLayout() 
    { 
     ItemSize = new CGSize((UIScreen.MainScreen.Bounds.Width/2) - 12, (UIScreen.MainScreen.Bounds.Height/3) - 40); 
     MinimumInteritemSpacing = 0f; 
    } 
} 
} 

Answer 1

Kraft, um die Bilddaten freizugeben, bevor die neue erstellt:

if (imgData != null) { 
    imgData.Dispose(); 
    imgData = null; 
} 
imgData = originalImage.AsJPEG(); 

Oder verwenden Sie lokale Variable mit using Satz:

using (NSData imgData = originalImage.AsJPEG()) { //imgData will be disposed immediately at the end of block 
    //...... 
}