I have a .zip file containing three jpg images.
I want to display all three of them in one FlowDocumentReader in WPF.
This is my code:
FlowDocument flowDoc = new FlowDocument();
ZipArchive zipFile = ZipFile.OpenRead("images.zip");
foreach (ZipArchiveEntry zip in zipFile.Entries)
{
Stream imageStream = zip.Open();
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = imageStream;
bitmapImage.EndInit();
bitmapImage.DownloadCompleted += BitmapImage_DownloadCompleted;
Image myImage = new Image
{
Source = bitmapImage,
Stretch = Stretch.Uniform
};
BlockUIContainer uiContainer = new BlockUIContainer
{
Child = myImage
};
flowDoc.Blocks.Add(uiContainer);
}
FlowDocReader.Document = flowDoc;
Up to the last line it always works without problems, but when the FlowDocumentReader loads the document there randomly appear problems:
Sometimes the code works well and alle three images are displayed in the FlowDocumentReader.
Sometimes some of the images are displayed with some errors (shifted colors at some bottom lines of pixels). I get no exception in this cases.
Sometimes only one, two or no image is displayed. In this case there is 2x per image not displayed Exception thrown: 'System.IO.InvalidDataException' in System.dll. This exception was originally thrown at this call stack: System.IO.Compression.InflaterZlib.Inflate(System.IO.Compression.ZLibNative.FlushCode)
I get all of this random results using the same .zip file. I can reproduce the problem using different .zip files.
Am I doing something wrong, or is there a known bug?
There are situations where BitmapImage does apparently not read its StreamSource until the end. This may for example occur when you read a bitmap from the response stream of a HTTP request.
I also observed it with the Stream returned from the ZipArchiveEntry.Open() method.
My workaround in these situations is to copy the frame buffer into an intermediate MemoryStream:
using (var archive = ZipFile.OpenRead("images.zip"))
{
foreach (var entry in archive.Entries)
{
using (var imageStream = entry.Open())
using (var memoryStream = new MemoryStream())
{
imageStream.CopyTo(memoryStream);
memoryStream.Seek(0, SeekOrigin.Begin);
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = memoryStream;
bitmapImage.EndInit();
...
}
}
}
Related
I have a WPF application that takes a snapshot image from a video file. The user can define the timestamp from which to take the image. The image is then saved to a temporary location on disk, and is then rendered into an <image> element.
The user should then be able to select a different timestamp, which then overwrites the temporary file on disk - this should then be displayed within the <image> element.
Using Image.Source = null;, I can clear the image file from the <image> element, so it displays a blank space instead. However, if the source image file is then overwritten with a new image (with the same name) and loaded into the <image> element, it still shows the old image.
I am using the following logic:
// Overwrite temporary file file here
// Clear out the reference to the temporary image
Image_Preview.Source = null;
// Load in new image (same source file name)
Image = new BitmapImage();
Image.BeginInit();
Image.CacheOption = BitmapCacheOption.OnLoad;
Image.UriSource = new Uri(file);
Image.EndInit();
Image_Preview.Source = Image;
The image displayed in the <image> element does not change, even though the original file has been completely replaced. Is there an image caching issue here that I am not aware of?
By default, WPF caches BitmapImages that are loaded from URIs.
You can avoid that by setting the BitmapCreateOptions.IgnoreImageCache flag:
var image = new BitmapImage();
image.BeginInit();
image.CreateOptions = BitmapCreateOptions.IgnoreImageCache;
image.CacheOption = BitmapCacheOption.OnLoad;
image.UriSource = new Uri(file);
image.EndInit();
Image_Preview.Source = image;
Or you load the BitmapImage directly from a Stream:
var image = new BitmapImage();
using (var stream = new FileStream(file, FileMode.Open, FileAccess.Read))
{
image.BeginInit();
image.CacheOption = BitmapCacheOption.OnLoad;
image.StreamSource = stream;
image.EndInit();
}
Image_Preview.Source = image;
Using .net Framework 4.8 I have a method to resize images to thumbnails. It seems to work OK as I can see the file properties after it’s resized and all looks good. However, when I execute the save method which should save the new thumbnail to a new folder, no files are found in the new folder. All paths are correct. And I can confirm that the source files have not been altered (as expected). Lastly I’m getting no errors. Any ideas what is going wrong?
This image’s original width is 600 and looking at the screenshot you can see the new width is 212, so this confirms we have a valid bitmap to save.
Thanks.
Like I have a bitmap like bmp Then Now I want to save it Like this way ....
BitmapImage bitmapimage;
using (MemoryStream memory = new MemoryStream())
{
bmp.Save(memory, System.Drawing.Imaging.ImageFormat.Bmp);
memory.Position = 0;
bitmapimage = new BitmapImage();
bitmapimage.BeginInit();
bitmapimage.StreamSource = memory;
bitmapimage.CacheOption = BitmapCacheOption.OnLoad;
bitmapimage.EndInit();
}
imgQR1.Source = bitmapimage;
string filePath = #"C:\Demo_Project\Image\test.png";
BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapimage));
using (var fileStream = new System.IO.FileStream(filePath, System.IO.FileMode.Create))
{
encoder.Save(fileStream);
}
The error is that the memory stream is not accessible when it is closed. It occurs when I try to set the previous image of the image control back to a Gif. When the previous image was a gif, I convert it to a bitmap with a memory stream. When the previous image was a normal png or jpg, it can display successfully.
I have tried to research how to fix the error. A solution I've tried is to convert the images to byte[] but then the gif isn't animating like they have been converted to a static image.
To display the gif I use a NuGet package called WPFAnimatedGif and to make the Wpf look better I use the NuGet package Materialdesigntheme
This is the event code that fires upon drag leave
if (previousIcon != null)
{
ToggleButton buttonControl = (ToggleButton)sender;
Image imageControl = (Image)((Grid)buttonControl.Content).Children[1];
if (previousIcon.ContainsKey(buttonControl))
ImageBehavior.SetAnimatedSource(imageControl, previousIcon[buttonControl]);
}
How I convert it
BitmapImage bmImage = new BitmapImage();
using (MemoryStream stream = new MemoryStream())
{
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(wbm));
encoder.Save(stream);
bmImage.BeginInit();
bmImage.CacheOption = BitmapCacheOption.OnLoad;
bmImage.StreamSource = stream;
bmImage.EndInit();
bmImage.Freeze();
}
For full code visit these Pastebins:
https://pastebin.com/PQkFAhQj
https://pastebin.com/wCEBeN1X
https://pastebin.com/wAERvDW3
Edit
Updated conversion function based upon responses
public BitmapImage ConvertWriteableBitmapToBitmapImage(WriteableBitmap wbm)
{
BitmapImage bmImage = new BitmapImage();
MemoryStream stream = new MemoryStream();
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(wbm));
encoder.Save(stream);
//stream.Position = 0;
bmImage.BeginInit();
bmImage.CacheOption = BitmapCacheOption.OnLoad;
bmImage.StreamSource = stream;
bmImage.EndInit();
bmImage.Freeze();
return bmImage;
}
I'm trying create a user perfil edit window, in this window has a Image control
When I selected a image file, it will show in this Image control and copy this file at my image folder, first time is all right, but second time, it show a error
"The process cannot access the file 'C:\1.jpg' because it is being used by another process."
I think it is because my Image control is using this file, so, I don't know what can I do
private void Select_Click(object sender, RoutedEventArgs e)
{
OpenFileDialog od = new OpenFileDialog();
if (od.ShowDialog() == true)
{
string imageLocal = #"C:/1.jpg";
File.Copy(od.FileName, imageLocal, true);
image1.Source = new BitmapImage(new Uri(imageLocal));
}
}
If you want to load and display an image, and keep the file amenable to operations in the file system (like reloading it or moving it to another directory), the Uri constructor will not work because (as you point out), the BitmapImage class hangs on to the file handle.
Instead, use a method like this...
private static BitmapImage ByStream(FileInfo info)
{ //http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/dee7cb68-aca3-402b-b159-2de933f933f1
try
{
if (info.Exists)
{
// do this so that the image file can be moved in the file system
BitmapImage result = new BitmapImage();
// Create new BitmapImage
Stream stream = new MemoryStream(); // Create new MemoryStream
Bitmap bitmap = new Bitmap(info.FullName);
// Create new Bitmap (System.Drawing.Bitmap) from the existing image file
(albumArtSource set to its path name)
bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
// Save the loaded Bitmap into the MemoryStream - Png format was the only one I
tried that didn't cause an error (tried Jpg, Bmp, MemoryBmp)
bitmap.Dispose(); // Dispose bitmap so it releases the source image file
result.BeginInit(); // Begin the BitmapImage's initialisation
result.StreamSource = stream;
// Set the BitmapImage's StreamSource to the MemoryStream containing the image
result.EndInit(); // End the BitmapImage's initialisation
return result; // Finally, set the WPF Image component's source to the
BitmapImage
}
return null;
}
catch
{
return null;
}
}
This method takes a FileInfo and returns a BitmapImage which you can display and simultaneously move it to another directory or display it again.
A much simpler method, copied from another answer below, is this:
public static BitmapImage LoadBitmapImage(string fileName)
{
using (var stream = new FileStream(fileName, FileMode.Open))
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = stream;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage;
}
}
The method shown below loads a BitmapImage from file and immediately closes the file after loading. Note that it is necessary to set the BitmapCacheOption.OnLoad flag when the source stream is closed right after EndInit.
public static BitmapImage LoadBitmapImage(string fileName)
{
using (var stream = new FileStream(fileName, FileMode.Open))
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = stream;
bitmapImage.EndInit();
bitmapImage.Freeze(); // just in case you want to load the image in another thread
return bitmapImage;
}
}
This code will work for any image format that is supported by WPF. When passing the image file content as stream to the StreamSource property, WPF will automatically create the appropriate decoder.
Very simple solution:
System.GC.Collect();
System.GC.WaitForPendingFinalizers();
File.Copy(od.FileName, imageLocal, true);
I'm trying create a user perfil edit window, in this window has a Image control
When I selected a image file, it will show in this Image control and copy this file at my image folder, first time is all right, but second time, it show a error
"The process cannot access the file 'C:\1.jpg' because it is being used by another process."
I think it is because my Image control is using this file, so, I don't know what can I do
private void Select_Click(object sender, RoutedEventArgs e)
{
OpenFileDialog od = new OpenFileDialog();
if (od.ShowDialog() == true)
{
string imageLocal = #"C:/1.jpg";
File.Copy(od.FileName, imageLocal, true);
image1.Source = new BitmapImage(new Uri(imageLocal));
}
}
If you want to load and display an image, and keep the file amenable to operations in the file system (like reloading it or moving it to another directory), the Uri constructor will not work because (as you point out), the BitmapImage class hangs on to the file handle.
Instead, use a method like this...
private static BitmapImage ByStream(FileInfo info)
{ //http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/dee7cb68-aca3-402b-b159-2de933f933f1
try
{
if (info.Exists)
{
// do this so that the image file can be moved in the file system
BitmapImage result = new BitmapImage();
// Create new BitmapImage
Stream stream = new MemoryStream(); // Create new MemoryStream
Bitmap bitmap = new Bitmap(info.FullName);
// Create new Bitmap (System.Drawing.Bitmap) from the existing image file
(albumArtSource set to its path name)
bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
// Save the loaded Bitmap into the MemoryStream - Png format was the only one I
tried that didn't cause an error (tried Jpg, Bmp, MemoryBmp)
bitmap.Dispose(); // Dispose bitmap so it releases the source image file
result.BeginInit(); // Begin the BitmapImage's initialisation
result.StreamSource = stream;
// Set the BitmapImage's StreamSource to the MemoryStream containing the image
result.EndInit(); // End the BitmapImage's initialisation
return result; // Finally, set the WPF Image component's source to the
BitmapImage
}
return null;
}
catch
{
return null;
}
}
This method takes a FileInfo and returns a BitmapImage which you can display and simultaneously move it to another directory or display it again.
A much simpler method, copied from another answer below, is this:
public static BitmapImage LoadBitmapImage(string fileName)
{
using (var stream = new FileStream(fileName, FileMode.Open))
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = stream;
bitmapImage.EndInit();
bitmapImage.Freeze();
return bitmapImage;
}
}
The method shown below loads a BitmapImage from file and immediately closes the file after loading. Note that it is necessary to set the BitmapCacheOption.OnLoad flag when the source stream is closed right after EndInit.
public static BitmapImage LoadBitmapImage(string fileName)
{
using (var stream = new FileStream(fileName, FileMode.Open))
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = stream;
bitmapImage.EndInit();
bitmapImage.Freeze(); // just in case you want to load the image in another thread
return bitmapImage;
}
}
This code will work for any image format that is supported by WPF. When passing the image file content as stream to the StreamSource property, WPF will automatically create the appropriate decoder.
Very simple solution:
System.GC.Collect();
System.GC.WaitForPendingFinalizers();
File.Copy(od.FileName, imageLocal, true);