i have written a programm that uses some picture ressources and creates a file from them.
As a Customer preview the images are shown before they get worked with. Therefore i need to dispose them before i can work with them. But i want to load the preview again afterwards and since it might be a huge number of pictures I want to do it dynamically, there i fail.
I use a Dictionary with the filename as String:
//Creating a Bitmap so we can preview the Picture.
try
{
mainDrawingBackgroundBitmap = new Bitmap(filePathBackgroundBackgroundImage);
if(mainAllBitmapsDictionary.ContainsKey(mainDrawingBackgroundBitmap))
{
mainAllBitmapsDictionary.Remove(mainDrawingBackgroundBitmap);
}
mainAllBitmapsDictionary.Add(mainDrawingBackgroundBitmap,filePathBackgroundBackgroundImage);
}
Now my Bitmap and path are in the Dictionary, later i dispose them this way:
private void DisposeAllFiles()
{
foreach (var tempBitmap in mainAllBitmapsDictionary.Keys)
{
tempBitmap.Dispose();
}
}
Which works just fine.
Now when i try to recreate the Bitmaps:
private void RessurrectAllFiles()
{
foreach (var tempAllBitmap in mainAllBitmapsDictionary)
{
try
{
var tempBitmap = tempAllBitmap.Key;
tempBitmap = new Bitmap(tempAllBitmap.Value);
}
catch (ArgumentException ae)
{
}
}
}
He doesn't fail or throw an error, the Dictionary even gets filled with Correct Bitmaps and strings but, those don't seem to affect the original objects anymore, so the Dictionary is as it was but when i inspect a Bitmap like the: mainDrawingBackgroundBitmap, i only see ArgumentExceptions.
To put it bluntly, where do i fail?
Keep path to images as keys, and bitmap data as values, so then it will be easy to you to manipulate data and searching dictionary will perform fast.
Dictionary<string, Bitmap>
Related
I need to extract all image frames from a DICOM SC using fo-DICOM. I have a test app that extracts and displays the images, which works fine. However, I need to save the individual images to a database, and am running into problems.
I have the following code so far:
public void SetImages(DicomFile dicom, ThumbResults results)
{
var images = new DicomImage(dicom.Dataset);
for(var count = 0; count < images.NumberOfFrames; count++)
{
var image = images.RenderImage(count).As<Bitmap>();
using(var stream = new MemoryStream())
{
image.Save(stream, ImageFormat.Jpeg);
results.Images.Add(Convert.ToBase64String(stream.ToArray()));
}
}
}
I get a DicomImagingException, "Cannot cast to 'Bitmap'" on images.RenderImage. It works in my test code, when I call PictureBox.Image = _image.RenderImage(count).As<Bitmap>(); so I figure RenderImage must be specifically for rendering (as the name implies).
How should I go about extracting individual frames to a string that will be saved to the database?
In case someone else runs into this problem, the issue was the original code was in .NET Framework, but the new code was in .NET Core. In Core, the ImageManager does not use the WindowsImageManager by default, so you need to set it manually.
ImageManager.SetImplementation(WinFormsImageManager.Instance);
i want to use the singleton pattern to create a buffer where all needed pictures are stored.
Something like that:
public sealed class BaseBuffer
{
private static readonly Dictionary<string, Bitmap> pictures = new Dictionary<string, Bitmap>();
public static Bitmap GetPicture(string name, ref Bitmap output)
{
//In case the pictureBuffer does not contain the element already
if (!pictures.ContainsKey(name))
{
//Try load picture from resources
try
{
Bitmap bmp = new Bitmap(System.Reflection.Assembly.GetEntryAssembly().GetManifestResourceStream("MyProject.Resources." + name + ".png"));
pictures.Add(name, bmp);
return bmp;
}
catch (Exception ex)
{
Console.WriteLine("Picture {0} cannot be found.", name);
}
}
else
{
return pictures[name];
}
return null;
}
Now im not sure. Does the "GetPicture" method return a copy of the picture or does it return a reference?
The application will need a few pictures which are displayed verry often on different Applications/Forms. Because of that it would be better to have only references to the pictures than copying them around.
Do you have any idea how to do that?
It'll return a reference to the Bitmap (as it is defined as a class) held within the dictionary. So no it doesn't return a distinct copy. Changes to the bitmap returned will be observed in the dictionary also as they will be the same underlying object. I'm not sure what you are doing with your ref Bitmap output as it doesn't appear to be used.
Also, TryGetValue on the dictionary will perform slightly better if this is called often:
Bitmap bmp;
if (!pictures.TryGetValue(name, out bmp))
{
bmp = new Bitmap(System.Reflection.Assembly.GetEntryAssembly().GetManifestResourceStream("MyProject.Resources." + name + ".png"));
pictures.Add(name, bmp);
}
return bmp;
Im not sure about that, butIi guess instead of doing return bmp; you should do output=bmp; and so on. Otherwise you could get rid of the parameter.
I also think, that even return bmp; and so on would return a reference but not a copy of the Bitmap stored in the dict. so either way would be fine...
How can I insert Image object into FileInfo list?
I have a list with images of this type
public List<FileInfo> _imagesList = new List<FileInfo>();
But I need to add image to this list using a method like this one:
public void AddImage(Image img)
{
}
I tried using this method
public void AddImage(string pathToImage)
{
try
{
FileInfo file = new FileInfo(pathToImage);
_imagesList.Add(file);
}
catch (Exception e)
{
MessageBox.Show("Не удалось загрузить изображение. Ошибка : " + e);
}
}
Let me explain why you can't do that. Image class does not have any references to file which was used to create that image. When you create Image instance with
Image.FromFile(filename)
File name is not stored anywhere. All you will have inside Image instance is an array of bytes which is initialized this way:
Stream dataStream = File.OpenRead(filename);
image.rawData = new byte[(int) dataStream.Length];
dataStream.Read(image.rawData, 0, (int) dataStream.Length);
So, the point is - you can't get file name from which Image was created. Actually image can be create not from file - from any stream (network stream, memory stream). Image is not related to any file, thus you can't insert it to list of FileInfo objects.
Well, as a workaround, you can save Image to file. And then insert that file to list.
you can either use the method you gave, adding new FileInfo(pathToImage) or change your list so it'll contain Image items
you can use
public List<Image> _imagesList = new List<Image>();
for example. if you share more information i could help you more. this looks like an XY problem so maybe you should tell us what's the real problem
You cannot do like this, FileInfo accept one arguments in its constructor: fileName.
You should have something like this:
public List<FileInfo> _imagesList = new List<FileInfo>();
public void Main()
{
AddImage("YourImagePath1");
AddImage("YourImagePath2");
// ...
}
public void AddImage(string path)
{
_imagesList.Add(new FileInfo(path));
//var img = Image.FromFile(path); // do this if you need to load your image
}
UPDATE:
You changed your question and your code now looks like mine, what was the issue in the code you used to have?
Alright it has come to this. I searched this website among many others and no one can seem to give me a straight answer so I'm going to try just asking outright. Been on this issue for about a solid 3 days and I can't afford to waste any more time on it.
Goal: The app I am building is in WPF and is going to be used as a bug tracker for a project my design team and I will be undertaking soon. Since we are going to be building a game in C++ most of the errors that occur will have a visual element to them so I inlcuded functionality to provide an image of the error in question when the user adds a bug to the list. I then take that image and save it to a local directory (for testing). Now the image path in the Error object points to a path that leads to the local directory. This functionality has been tested and works fine. My problem showes up when I want to delete a bug from the list. I am getting that very infamous "IO Exception" saying that the image I want to delete is being used by another process.
So Far: At first I tried very elegant solutions, but as with all things you get to a point where you just want to see if you can get the thing to even work at all. So I am at the point where most of the code I am using is experimental and radical. So please when looking at it note that the code being used is out of desperation, so any "simple" solutions have probably already been tried (I did research this a lot becuase I hate having to do this). Things i can think of off the top of my head are the obsurd amount of disposes and forced garbage collections being called so please to not comment on the negative nature of this practice, I am well aware :).
The Code
Saving image to local directory
public void OnBrowseClick()
{
Microsoft.Win32.OpenFileDialog openBox = new Microsoft.Win32.OpenFileDialog();
// Show dialog box to user and grab output
Nullable<bool> result = openBox.ShowDialog();
if (result == true)
{
// Create temp variable to hold local path string
string localPath = Directory.GetCurrentDirectory();
// Grab the extension of the specified file path
string extension = openBox.FileName.Substring(openBox.FileName.LastIndexOf("\\"));
// Add extension to local path
localPath += extension;
// Create local copy of image at given file path (being ridiculous at this point)
using (Stream stream = new FileStream(openBox.FileName, FileMode.Open, FileAccess.ReadWrite))
{
using (Bitmap bmp = LoadImage(stream))
{
using (Bitmap temp = (Bitmap)bmp.Clone())
{
temp.Save(localPath);
temp.Dispose();
}
bmp.Dispose();
}
stream.Dispose();
}
// Set the URL in the image text box (UI stuff)
LocalError.ImagePath = localPath;
}
}
The following is the LoadImage function that is used in the function above
private Bitmap LoadImage(Stream stream)
{
Bitmap retval = null;
using (Bitmap bitmap = new Bitmap(stream))
{
retval = new Bitmap(bitmap.Width, bitmap.Height, bitmap.PixelFormat);
using (Graphics gdi = Graphics.FromImage(retval))
{
gdi.DrawImageUnscaled(bitmap, 0, 0);
gdi.Flush();
gdi.Dispose();
bitmap.Dispose();
}
}
// Garbage collection here to be safe
GC.WaitForPendingFinalizers();
GC.Collect();
return retval;
}
And finally we come to where I try to delete the image
public void OnDeleteClick()
{
// Ask user to make sure they want to delete selected item(s)
MessageBoxResult result = MessageBox.Show("Are you sure you want to delete selected item(s) from the list?",
"Delete", MessageBoxButton.YesNo);
if (result == MessageBoxResult.Yes)
{
for( int i = 0; i < Parent.ErrorListControl.ErrorDataGrid.SelectedItems.Count; ++i)
{
// Get path to image
string path = (Parent.ErrorListControl.ErrorDataGrid.SelectedItems[i] as Error).ImagePath;
// Even tried calling garbage collection here!!!!!
System.GC.WaitForPendingFinalizers();
System.GC.Collect();
File.Delete(path);
// Remove the error from the error list
Parent.ErrorListVM.ErrorList.Remove((Error)Parent.ErrorListControl.ErrorDataGrid.SelectedItems[i]);
// Decrement counter because we altered the list while in a loop
i--;
}
}
}
Notes: If anyone would like me to explain anything further or if you need to know something I left out please just ask I will get back to you ASAP! Any suggestions are helpful at this point I have absolutley no idea what I am doing wrong. I generally only program in a C++ environment so I tend to manage my own memory this whole "garbage collection" thing is really throwing a wrench in our project! (Off topic note: I do not know why I am not getting any color highlighting so I apologize to anyone who takes the time to read this).
Here's a simple way to do what you want. In this example, I'm using Path.GetTempFileName() to generate a random file name in the local user's temp directory. If you don't need to persist the files then it's a good place to store them temporarily. Also, the user could theoretically import two files with the same name. So you want to use some kind of random filename generation or other mechanism to avoid conflicts.
private void browseButton_Click(object sender, RoutedEventArgs e)
{
var openFileDialog = new Microsoft.Win32.OpenFileDialog();
if (openFileDialog.ShowDialog(this) == true)
{
using (Bitmap originalImage = new Bitmap(openFileDialog.FileName))
{
string tempFileName = System.IO.Path.GetTempFileName();
originalImage.Save(tempFileName);
// LocalError.LocalPath
LocalPath = tempFileName;
}
}
}
private void deleteButton_Click(object sender, RoutedEventArgs e)
{
if (File.Exists(LocalPath))
{
File.Delete(LocalPath);
}
}
Although a simple File.Copy should suffice as long as you have the right paths, I was just providing a solution that matched your question.
EDIT:
Actually the current directory does not seem to be changed by the OpenFileDialog. I could swear that it did at some point. So I don't think this is your problem. Regardless, this code still works for me and you shouldn't require anything more complicated than this.
EDIT #2:
It seems the lock is actually caused by the image being databound to the view and presumably locked by the BitmapSource. You should be able to create it without locking the file. Generally, this is slower so don't do it this way unless you need to be able to modify or delete the file.
bitmapSource = new BitmapImage();
bitmapSource.BeginInit();
bitmapSource.CacheOption = BitmapCacheOption.OnLoad;
bitmapSource.CreateOption = BitmapCreateOptions.IgnoreImageCache;
bitmapSource.UriSource = new Uri(ImagePath, UriKind.Absolute);
bitmapSource.EndInit();
Since your LoadImage method does simple copy of the image, why not use File.Copy(source, dest) and avoid all the bitmaps, drawings, etc? Your goal might be to modify local bitmap after it's created, but it can still be done after copy.
Also, when using the using block, explicit .Dispose() is not required, as using block does it for you:
using (var obj = new SomeDisposableObject())
{
// code here
// obj.Dispose(); <-- not needed, since...
} // ...at this point obj.Dispose is called automatically.
I'm having to fix a bug in some very old code that converts a Base64 string to a image using Memory Stream. Basically it loops through a list of images stored as base64 strings and converts them to images then draws them using ActiveReports.
The bug is that once it loads one image all following images will be a copy of the first image.
I found the code that is doing the conversion of string to image and immediately noticed it isn't disposing of the memory stream. If I wrap the memory stream in a using block I get a GDI exception. I'm guessing this is because the image isn't really read from memory yet or something, but I'd like to hear if anyone has a guess. Thanks in advance!
byte[] oGraphic = null;
try
{
oGraphic = Convert.FromBase64String(psGraphic);
DataDynamics.ActiveReports.Picture oImg = new Picture();
oImg.Top = this.Legend.Top + this.fTopFirst;
oImg.Visible = true;
oImg.Name = sLabelName;
oImg.PictureAlignment = PictureAlignment.Center;
oImg.Image = null;
if (oGraphic != null)
{
var oStream = new MemoryStream(oGraphic);
oImg.Image = System.Drawing.Image.FromStream(oStream);
oImg.Height = Convert.ToSingle(oImg.Image.Height)/(oImg.Image.VerticalResolution);
oImg.Width = Convert.ToSingle(oImg.Image.Width)/(oImg.Image.HorizontalResolution);
oImg.SizeMode = SizeModes.Zoom;
this.fGraphicHeight = oImg.Height;
this.fGraphicWidth = oImg.Width;
if (this.fConstantGraphic > this.fGraphicWidth)
oImg.Left = this.Legend.Left + this.fLeftFirst +
((this.fConstantGraphic - this.fGraphicWidth)/2);
else
oImg.Left = this.Legend.Left + this.fLeftFirst;
}
else
{
this.fGraphicHeight = 0f;
this.fGraphicWidth = 0f;
}
this.GHMap.Controls.Add(oImg);
}
catch (Exception oE)
{
.....
}
The only thing I can imagine is if there is a line of code missing from what you have here:
if (oGraphic == null) // missing line
oGraphic = Convert.FromBase64String(psGraphic);
There is no reason for this byte[] to be declared outside of the try { } block. That array gets wrapped into a MemoryStream which is then wrapped into an Image. That image is attached to a brand new Picture which is added to a Picture collection.
What is it we don't see?
Here's another guess (I'll leave the first guess alone for posterity):
I'm not familiar with Active Reports, but it looks like you're setting the Top and PictureAlignment properties of the Picture object to the same value and adding more than one Picture. Is it possible they are all there, but one on top of each other? So the result is a single picture?
Guess #3 (one of these is going to get a checkmark, I just know it!)
Everything looks OK in the code provided, therefore the problem is somewhere else (though it's still entirely possible I'm wrong about it being OK).
Are you certain that psGraphic is different each time this code is executed?
The cause of the problem is that the Picture control is a single control instance on a single section. So you're just overwriting the image on this single control over and over.
If the only thing you want to see in this report is the images, then the best thing to do is use ActiveReports' Unbound mode and treat each image as another "record". See this walkthrough for an example of using unbound mode (see the DataInitialize and FetchData events for the meat of the matter).
Using unbound mode, ActiveReports will render the image one after the other in sections treating each image like a new record. The code would be something like the following (sorry I don't have ActiveReports handy at the moment so I can't check this code, but this should be pretty close. Let me know if you run into any problems and I'll clean it up in the morning):
In ActiveReports' ReportStart Event:
DataDynamics.ActiveReports.Picture oImg = new Picture();
oImg.Top = 0;
oImg.Visible = true;
oImg.Name = sLabelName;
oImg.PictureAlignment = PictureAlignment.Center;
// setting DataField "binds" the Picture control to get it's data from the MyImageField field which we'll initialize and bind in the events below
oImg.DataField = "MyImageField";
this.Sections["Detail"].Controls.Add(oImg);
In ActiveReports' DataInitialize Event:
this.Fields.Add("MyImageField");
In ActiveReports FetchData Event:
var imageBytes = Convert.FromBase64String(_imageStrings.Current); // I'm not sure where the base64 image strings come from, some I'm assuming you can put them in an enumerator field in the report like "_imageStrings"
var imageStream = new MemoryStream(imageBytes);
var image = Image.FromStream(imageStream);
Fields["MyImageField"].Value = image;
// This tells ActiveReports if there are more records, and if it should raise the FetchData event again (allowing you to add another image).
eArgs.EOF = !_imageStrings.MoveNext();
If you need to resize the image control for each image, use the section's Format event for that. You could use something like the following:
In Detail_Format Event:
var pictureControl = this.Sections["Detail"].Controls["MyImageControl"] as DataDynamics.ActiveReports.Picture;
pictureControl.Width = Convert.ToSingle(pictureControl.Image.Width)/(pictureControl.Image.VerticalResolution);
pictureControl.Width = Convert.ToSingle(pictureControl.Image.Width)/(pictureControl.Image.HorizontalResolution);
Finally, ActiveReports will also just automatically bind to a set of POCO objects in an IEnumerable (or IList, I forget). So you could simply have a "MyImage" class with a property like "MyImage" and ActiveReports will read it and bind with it (you wouldn't have to write any code in DataInitialize and FetchData). I think you might also just be able to put the MemoryStream in there as the binding too and ActiveReports will read it, but I'm not positive on that.
BTW: The reason that GDI exception occurs when disposing the MemoryStream is because GDI attempts to just seek within that single MemoryStream for the image data rather than making a copy of it. So you'll need to supply each System.Drawing.Image instance with a new stream (don't worry MemoryStream will clean itself up when everything is released).
It turned out to be a problem with the way we were creating the image. Adding the code below fixed the problem.
oImg.Image = System.Drawing.Image.FromStream(oStream);
TO THIS
oImg.Image = ImageFromBase64String(psGraphic);
private Image ImageFromBase64String(string sBase64String)
{
using (var sStream = new MemoryStream(Convert.FromBase64String(sBase64String)))
using (var iSourceImage = Image.FromStream(sStream))
{
return new Bitmap(iSourceImage);
}
}