加载BitmapSources时出现内存问题 [英] Memory Issues when loading BitmapSources

问题描述

我正在尝试为WPF应用程序创建一个简单的Photo-Viewer.实际上它已经存在并且可以正常工作了:)

I am trying to create a simple Photo-Viewer for my WPF application. Actually it already exists and works almost fine :)

查看器包含两个主要元素:

The viewer consists of two main elements:

1:一个列表框，显示选定目录中的所有图像

1: a ListBox, that shows all images within a selected directory

2:显示从列表框中选择的项目的图像

2: an Image that shows the selected item from the listbox

问题:当目录中包含大量图像时，应用程序内存不足.

Problem: When I have a large number of images within a directory the app runs out of memory.

详细信息:

列表框(1)-数据源是一个可观察到的集合，它包含如下对象，并且显示该对象的Thumbnail属性:    

The listbox (1) -datasource is an observable collection wich contains objects like the following and it displays the Thumbnail property of the object:             

 public class ImageFile
    {
        private bool thumbnailLoaded = false;
        private readonly string thumbnailPath;
        private readonly int standardWidth;
        
        
        public ImageFile(string path, string name = null, string thumbPath = null)
        {
            if (path == null)
                throw new ArgumentException("Argument 'path' may not be null");
            Path = name==null ? path : System.IO.Path.Combine(path, name);
            Name = name;
            thumbnailPath = thumbPath;
        }

        public ImageFile(BitmapFrame sourceFrame)
        {
            Image = sourceFrame;
            standardWidth = 1600;
        }

        public void SetThumbnail()
        {
            if (Thumbnail != null) return;
            if (thumbnailPath != null)
            {
                Thumbnail = ImageUtils.GetImage(thumbnailPath);
                thumbnailLoaded = true;
            }
        }

        public void RemoveThumbnail()
        {
            thumbnailLoaded = false;
            Thumbnail = null;
        }
        
        public string Name { get; set; }
      
        public BitmapFrame Image
        {
            get
            {
                if (image == null && !string.IsNullOrEmpty(Path))
                {
                    var tmpImg = ImageUtils.GetBitmapFrame(Path);
                    Initialize(tmpImg);
                    return ImageUtils.GetImage(Path, standardWidth);
                }
                return image;
            }
            private set
            {
                if (value != null)
                {
                    image = value;
                    Initialize(image);
                    image.Freeze();
                }
            }
        }
       
        public BitmapSource Thumbnail { get; private set; }
       
        public String Path { get; private set; }
       
        public BitmapMetadata Metadata { get; private set; }
        public ReadOnlyCollection<ColorContext> ColorContexts { get; private set; }
       
        private void Initialize(BitmapFrame tmpImage)
        {
            Metadata = (BitmapMetadata)tmpImage.Metadata;
            ColorContexts = tmpImage.ColorContexts;
            if (!thumbnailLoaded)
            {
                SetThumbnail(tmpImage);
            }
            
        }
    }

public static BitmapFrame GetImage(string path, int resizedWidth = 0)
        {
            //No Metadata here :(
            if (!string.IsNullOrEmpty(path))
            {
                var info = new FileInfo(path);
                if (info.Exists && info.Length > 0)
                {
                    var bi = new BitmapImage();

                    bi.BeginInit();
                    if(resizedWidth!=0)
                        bi.DecodePixelWidth = resizedWidth;
                    bi.CacheOption = BitmapCacheOption.OnLoad;
                    bi.UriSource = new Uri(info.FullName);
                    bi.EndInit();
                    return BitmapFrame.Create(bi);
                }
            }
            return null;
        }

我遇到的问题是，即使我仅设置了缩略图那些可见的图像文件

The problem I am having is, that even though I only set the thumbnails for those ImageFiles that are visible

并在其他图像文件上调用Remove()，则内存消耗增加.

and call Remove() on the others, the memory consumption goes up.

仅当我开始在WPF中的图像组件(2)中编辑图像时，才调用图像"属性.

The property 'Image' is only called, when I start editing the image in the image component (2) in WPF.

(我不想使用私有字段将图像存储在此处，因为我希望节省内存)

(I do not use a private field to store the image there, because I hoped to save memory)

我该怎么办才能保持较低的内存使用率?我需要能够打开目录

What can I do to keep the memory usage low? I need to be able to open directories

，其中包含无限数量的图像.

containing an unlimited number ofimages.

任何帮助表示感谢.有没有更好的方法可以做到这一点?

Any Help appreciated. Is there a better way to achieve this?

谢谢

Jens

---

JEns D.

---

JEns D.

推荐答案

"任何帮助表示赞赏.有没有更好的方法来实现这一目标?"

"Any Help appreciated. Is there a better way to achieve this?"

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