I have build a program which allows me to insert comment and the title of an Image through System.Image.Drawing so right now, I have trouble trying to overwrite the existing Jpeg file with the one that has comment and title added into it, but I am encountering error while deleting the file, so I'm not sure what to do as I have tried disposing the file but I cant saved it in that case, due to the fact that I disposed it too early, but I cant saved it because the existing file name is not deleted so I'm kinda stuck in the middle right now.
Here are my codes for it:
public string EditComment(string OriginalFilepath, string newFilename)
{
image = System.Drawing.Image.FromFile(OriginalFilepath);
PropertyItem propItem = image.PropertyItems[0];
using (var file = System.Drawing.Image.FromFile(OriginalFilepath))
{
propItem.Id = 0x9286; // this is the id for 'UserComment'
propItem.Type = 2;
propItem.Value = System.Text.Encoding.UTF8.GetBytes("HelloWorld\0");
propItem.Len = propItem.Value.Length;
file.SetPropertyItem(propItem);
PropertyItem propItem1 = file.PropertyItems[file.PropertyItems.Count() - 1];
file.Dispose();
image.Dispose();
string filepath = Filepath;
if (File.Exists(#"C:\Desktop\Metadata"))
{
System.IO.File.Delete(#"C:\Desktop\Metadata");
}
string newFilepath = filepath + newFilename;
file.Save(newFilepath, ImageFormat.Jpeg);//error appears here
return filepath;
}
}
The Error shown are:
An exception of type 'System.ArgumentException' occurred in System.Drawing.dll but was not handled in user code
Additional information: Parameter is not valid.
The problem is that opening an image from file locks the file. You can get around that by reading the file into a byte array, creating a memory stream from that, and then opening the image from that stream:
public string EditComment(string originalFilepath, string newFilename)
{
Byte[] bytes = File.ReadAllBytes(originalFilepath);
using (MemoryStream stream = new MemoryStream(bytes))
using (Bitmap image = new Bitmap(stream))
{
PropertyItem propItem = image.PropertyItems[0];
// Processing code
propItem.Id = 0x9286; // this is the id for 'UserComment'
propItem.Type = 2;
propItem.Value = System.Text.Encoding.UTF8.GetBytes("HelloWorld\0");
propItem.Len = propItem.Value.Length;
image.SetPropertyItem(propItem);
// Not sure where your FilePath comes from but I'm just
// putting it in the same folder with the new name.
String newFilepath;
if (newFilename == null)
newFilepath = originalFilePath;
else
newFilepath = Path.Combine(Path.GetDirectory(originalFilepath), newFilename);
image.Save(newFilepath, ImageFormat.Jpeg);
return newFilepath;
}
}
Make sure you do not dispose your image object inside the using block as you did in your test code. Not only does the using block exist exactly so you don't have to dispose manually, but it's also rather hard to save an image to disk that no longer exists in memory. Similarly, you seem to open the image from file twice. I'm just going to assume all of those were experiments to try to get around the problem, but do make sure to clean those up.
The basic rules to remember when opening images are these:
An Image object created from a file will lock the file during the life cycle of the image object, preventing the file from being overwritten or deleted until the image is disposed.
An Image object created from a stream will need the stream to remain open for the entire life cycle of the image object. Unlike with files, there is nothing actively enforcing this, but after the stream is closed, the image will give errors when saved, cloned or otherwise manipulated.
Contrary to what some people believe, a basic .Clone() call on the image object will not change this behaviour. The cloned object will still keep the reference to the original source.
Note, if you actually want a usable image object that is not contained in a using block, you can use LockBits and Marshal.Copy to copy the byte data of the image object into a new image with the same dimensions and the same PixelFormat, effectively making a full data clone of the original image. (Note: I don't think this works on animated GIF files) After doing that, you can safely dispose the original and just use the new cleanly-cloned version.
There are some other workarounds for actually getting the image out, but most of them I've seen aren't optimal. These are the two most common other valid workarounds for the locking problem:
Create a new Bitmap from an image loaded from file using the Bitmap(Image image) constructor. This new object will not have the link to that file, leaving you free to dispose the one that's locking the file. This works perfectly, but it changes the image's colour depth to 32-bit ARGB, which might not be desired. If you just need to show an image on the UI, this is an excellent solution, though.
Create a MemoryStream as shown in my code, but not in a using block, leaving the stream open as required. Leaving streams open doesn't really seem like a good idea to me. Though some people have said that, since a MemoryStream is just backed by a simple array, and not some external resource, the garbage collector apparently handles this case fine...
I've also seen some people use System.Drawing.ImageConverter to convert from bytes, but I looked into the internals of that process, and what it does is actually identical to the last method here, which leaves a memory stream open.
Related
Having a code that works for ages when loading and storing images, I discovered that I have one single image that breaks this code:
const string i1Path = #"c:\my\i1.jpg";
const string i2Path = #"c:\my\i2.jpg";
var i = Image.FromFile(i1Path);
i.Save(i2Path, ImageFormat.Jpeg);
The exception is:
System.Runtime.InteropServices.ExternalException occurred
A generic error occurred in GDI+.
at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
at System.Drawing.Image.Save(String filename, ImageFormat format)
at ...
As far as I can see, there is nothing special about the image. It is approx 250 pixels in size and can be opened in e.g. Windows Image Viewer or Paint.NET:
(Since the image above, after being uploaded to Stack Overflow does not produce the error anymore, I've put the original image here)
What I discovered is that upon calling the Save method, the destination image file is being created with zero bytes.
I am really clueless on what causes the error.
My questions:
Can you think of any special thing that would hinder .NET from saving the image?
Is there any way (beside panicing) to narrow down these kind of errors?
While I still did not find out the reason what exactly caused the error when saving the image, I found a workaround to apply:
const string i1Path = #"c:\my\i1.jpg";
const string i2Path = #"c:\my\i2.jpg";
var i = Image.FromFile(i1Path);
var i2 = new Bitmap(i);
i2.Save(i2Path, ImageFormat.Jpeg);
I.e. by copying the image internally into a Bitmap instance and saving this image instead of the original image, the error disappeared.
I'm assuming that by copying it, the erroneous parts the caused the original Save call to fail are being removed an/or normalized, thus enabling the save operation to succeed.
Interestingly, the so stored image has a smaller file on disk (16 kB) than its original source (26 kB).
First of all make sure, that the desired folder has Read/Write permissions. Changing the permissions solved this problem for me.
Solution is here, you must dispose image object to release the memory on the server.
Try use using statement. Make sure destination directory on server exists too.
The reason may be that the image is loaded lazily and the loading process is not yet finished when you try to save it.
Following what's said in this blog post (assuming you're German by the picture you linked in your question) provides a possible solution. Also this SO question's accepted answer indicates this is due to the fact the image file you're trying to save to is locked.
EDIT
For Ulysses Alves, from the linked blog entry: If you load an image using Image.FromFile() it remains locked until it is disposed of. This prevents calls to Save().
pictureBox1.Image = Image.FromFile("C:\\test\\test1.jpg");
pictureBox1.Image.Save("C:\\test\\test2.jpg");
The above code throws an error.
To make it work, you need to copy the image. The following code works:
pictureBox1.Image = Image.FromFile("C:\\test\\test1.jpg");
Image copy = pictureBox1.Image;
copy.Save("C:\\test\\test2.jpg")
I found this question because I also faced the similar error and the file was actually created with zero length (if you don't see any file, first check the permissions to write into folder as other answers suggest). Although my code was slightly different (I use stream to read the image from memory, not from file), I think my answer may be helpful to anyone facing similar problem.
It may looks counter-intuitive, but you can't really dispose memory stream until you finish with image.
NOT WORKING:
Image patternImage;
using (var ms = new MemoryStream(patternBytes)) {
patternImage = new Bitmap(ms);
}
patternImage.Save(patternFile, ImageFormat.Jpeg);
Just don't dispose the stream until you done with image.
WORKS:
using (var ms = new MemoryStream(patternBytes)) {
patternImage = new Bitmap(ms);
patternImage.Save(patternFile, ImageFormat.Jpeg);
}
What is misleading:
Error message doesn't really tell you anything
You can see the image properties, like width and height, but can't
save it
my solution was to make, write temp content (File.WriteAllText) just before saving the file
Here is the code:
var i = Image.FromFile(i1Path);
File.WriteAllText(i2Path, "empty"); // <---- magic goes here
i.Save(i2Path, ImageFormat.Jpeg);
Please try and let me know
In my case I have accidentally deleted the directory where image was getting stored.
Key Information:
// Using System.Drawing.Imaging:
new Bitmap(image).Save(memoryStream, ImageFormat.Jpeg);
You MUST Cast the Image to a Bitmap to Save it.
Using:
// Using System.Drawing.Imaging:
image.Save(memoryStream, ImageFormat.Jpeg);
WILL throw the Error:
Generic GDI+ error when saving an image
Just use the visual studio as administrator or run the application created by the code as administrator it should work smoothly.
It is user access rights issue.
I faced the same and resolved it by running visual studio as administrator.
In my case, I set validateImageData to false:
Image.FromStream(stream, validateImageData: false);
solution:
Image.FromStream(stream, validateImageData: true);
Open in the program
const string i1Path = #"c:\my\i1.jpg";
const string i2Path = #"c:\my\i2.jpg";
var i = Image.FromFile(i1Path);
i.Save(i2Path, ImageFormat.Jpeg);
i.Dispose();
I am trying download an image from a website and put it in a picturebox.
// response contains HttpWebResponse of the page where the image is
using (Stream inputStream = response.GetResponseStream()) {
using (Stream outputStream = File.Open(fileName, FileMode.Create)) {
byte[] buffer = new byte[4096];
int bytesRead;
do {
bytesRead = inputStream.Read(buffer, 0, buffer.Length);
outputStream.Write(buffer, 0, bytesRead);
} while (bytesRead != 0);
}
}
response.Close();
After that, the downloaded image is assigned to a PictureBox like such:
if (imageDownloaded) {
pictureBox1.Image = Image.FromFile(filePath);
}
This all works like a charm first time, but the second time I run the code I get System.IO.IOException: "Additional information: The process cannot access the file ...(file path) ... because it is being used by another process.". I have no idea why...
I looked at 4 other threads such as this one, but they were basically stressing out the need to close streams, which I do, so none of them helped me.
Before you recommend to use pictureBox1.Load() I can't because I need the image downloaded for further development.
EDIT 1: I have actually tried to dispose the image by putting pictureBox1.Image = null before the code above is executed. It is still giving me an exception.
The Image.FromFile docs state:
The file remains locked until the Image is disposed.
So you need to dispose your Image too to be able to overwrite the file.
Try using the Clone method on your image and dispose the original Image.
The thing is related to the Image.FromFile. If we read a documentation, there is a note:
The file remains locked until the Image is disposed.
This pretty much explains the behavior you get.
To resolve this, you might need to create a copy of the image and assign it to a PictureBox .
From MSDN:
The file remains locked until the Image is disposed.
This means its the PictureBox that is holding the file open.
You have two options:
Dispose of the PictureBox image before writing the new file.
Download the file, make a copy of it and load the copy into the PictureBox - this allows you to write over the downloaded file freely.
I'll be the contrarian here. :)
While cloning/copying the image will resolve the exception, it raises a different question: why are you overwriting to the same file for a new image?
It seems to me that a better approach would be to download subsequent files to different file names (if they are really different files), or to simply reuse the file already downloaded instead of hitting the network again (if it's just a new request for the same file).
Even if you want to repeatedly download the same file (perhaps you expect the actual file contents to change), you can still download to a new name (e.g. append a number to the file name, use a GUID for the local file name, etc.)
Having a code that works for ages when loading and storing images, I discovered that I have one single image that breaks this code:
const string i1Path = #"c:\my\i1.jpg";
const string i2Path = #"c:\my\i2.jpg";
var i = Image.FromFile(i1Path);
i.Save(i2Path, ImageFormat.Jpeg);
The exception is:
System.Runtime.InteropServices.ExternalException occurred
A generic error occurred in GDI+.
at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
at System.Drawing.Image.Save(String filename, ImageFormat format)
at ...
As far as I can see, there is nothing special about the image. It is approx 250 pixels in size and can be opened in e.g. Windows Image Viewer or Paint.NET:
(Since the image above, after being uploaded to Stack Overflow does not produce the error anymore, I've put the original image here)
What I discovered is that upon calling the Save method, the destination image file is being created with zero bytes.
I am really clueless on what causes the error.
My questions:
Can you think of any special thing that would hinder .NET from saving the image?
Is there any way (beside panicing) to narrow down these kind of errors?
While I still did not find out the reason what exactly caused the error when saving the image, I found a workaround to apply:
const string i1Path = #"c:\my\i1.jpg";
const string i2Path = #"c:\my\i2.jpg";
var i = Image.FromFile(i1Path);
var i2 = new Bitmap(i);
i2.Save(i2Path, ImageFormat.Jpeg);
I.e. by copying the image internally into a Bitmap instance and saving this image instead of the original image, the error disappeared.
I'm assuming that by copying it, the erroneous parts the caused the original Save call to fail are being removed an/or normalized, thus enabling the save operation to succeed.
Interestingly, the so stored image has a smaller file on disk (16 kB) than its original source (26 kB).
First of all make sure, that the desired folder has Read/Write permissions. Changing the permissions solved this problem for me.
Solution is here, you must dispose image object to release the memory on the server.
Try use using statement. Make sure destination directory on server exists too.
The reason may be that the image is loaded lazily and the loading process is not yet finished when you try to save it.
Following what's said in this blog post (assuming you're German by the picture you linked in your question) provides a possible solution. Also this SO question's accepted answer indicates this is due to the fact the image file you're trying to save to is locked.
EDIT
For Ulysses Alves, from the linked blog entry: If you load an image using Image.FromFile() it remains locked until it is disposed of. This prevents calls to Save().
pictureBox1.Image = Image.FromFile("C:\\test\\test1.jpg");
pictureBox1.Image.Save("C:\\test\\test2.jpg");
The above code throws an error.
To make it work, you need to copy the image. The following code works:
pictureBox1.Image = Image.FromFile("C:\\test\\test1.jpg");
Image copy = pictureBox1.Image;
copy.Save("C:\\test\\test2.jpg")
I found this question because I also faced the similar error and the file was actually created with zero length (if you don't see any file, first check the permissions to write into folder as other answers suggest). Although my code was slightly different (I use stream to read the image from memory, not from file), I think my answer may be helpful to anyone facing similar problem.
It may looks counter-intuitive, but you can't really dispose memory stream until you finish with image.
NOT WORKING:
Image patternImage;
using (var ms = new MemoryStream(patternBytes)) {
patternImage = new Bitmap(ms);
}
patternImage.Save(patternFile, ImageFormat.Jpeg);
Just don't dispose the stream until you done with image.
WORKS:
using (var ms = new MemoryStream(patternBytes)) {
patternImage = new Bitmap(ms);
patternImage.Save(patternFile, ImageFormat.Jpeg);
}
What is misleading:
Error message doesn't really tell you anything
You can see the image properties, like width and height, but can't
save it
my solution was to make, write temp content (File.WriteAllText) just before saving the file
Here is the code:
var i = Image.FromFile(i1Path);
File.WriteAllText(i2Path, "empty"); // <---- magic goes here
i.Save(i2Path, ImageFormat.Jpeg);
Please try and let me know
In my case I have accidentally deleted the directory where image was getting stored.
Key Information:
// Using System.Drawing.Imaging:
new Bitmap(image).Save(memoryStream, ImageFormat.Jpeg);
You MUST Cast the Image to a Bitmap to Save it.
Using:
// Using System.Drawing.Imaging:
image.Save(memoryStream, ImageFormat.Jpeg);
WILL throw the Error:
Generic GDI+ error when saving an image
Just use the visual studio as administrator or run the application created by the code as administrator it should work smoothly.
It is user access rights issue.
I faced the same and resolved it by running visual studio as administrator.
In my case, I set validateImageData to false:
Image.FromStream(stream, validateImageData: false);
solution:
Image.FromStream(stream, validateImageData: true);
Open in the program
const string i1Path = #"c:\my\i1.jpg";
const string i2Path = #"c:\my\i2.jpg";
var i = Image.FromFile(i1Path);
i.Save(i2Path, ImageFormat.Jpeg);
i.Dispose();
I want to delete a file on my computer but the app throws an exception that The directory is busy. My first thought is to implement a dispose method in my class which does a file delete.
Knows anybody how to do this?
It's actually a Picturebox which displays a image and if you click on a button beside the image you can remove it, thus deleting it. It's propably that which blocks my filepath.
picobx.Image = Image.FromFile(//path)
Is there any solution to this?
PS. I want to dispose the resource so that I can delete...
do like this:
File.Delete(// path )
The Image.FromFile method actually locks the file thats why you can't delete it. The best would be to read the image as a byte array using bytes = File.ReadBytes(filename), create a memorystream from the byte array, pass the memory stream to Image.FromStream to display the image and then delete it with the button click.
OK - I see what you are tring to do.
Image itself implements IDisposable. You don't need to implement IDisposable yourself, you just have to make sure you either call Dispose on your image, or use the "using" syntax.
The problem is that until the image - the returned reference from Image.FromFile(//path) - is disposed of, it still locks the underlying file so you will always get the exception "The process cannot access the file"
What you intend to do is the following, I suppose:
try {
File.Delete(yourFile);
}
catch (IOException ex) {
// Do something with the exception here, like showing the user that the file can't be deleted)
}
A file that i.e. is in use or in an directory with insufficient rights can't be deleted. So if you get an error, you should look why the file is in use / not accessible, whatever.
Based on your edit, I suggest to do the following:
Image myImage = Image.FromFile(//path);
picobx.Image = myImage;
//click button
picobx.Image = null;
myImage.Dispose();
File.Delete(//path);
As you have suggested you will need to dispose of the image before you can delete it something like this:
Image i = this.pictureBox1.Image;
this.pictureBox1.Image = null;
i.Dispose();
File.Delete(filePath);
Edit I posted this without reading his new edit: I see you're using Image.FromFile.
If the file does not have a valid image format or if GDI+ does not support the pixel format of the file, this method throws an OutOfMemoryException exception.
You're going to have to dispose of the Image before you can delete it.
Image.FromFile
The file remains locked until the Image is disposed.
private Image image;
in your image load function:
image = Image.FromFile("path");
picobx.Image = image;
this goes in your delete method;
image.Dispose;
File.Delete("path");
--- No longer relevant ---
If you're reading the file from a stream and converting the stream to an image. Then you try and delete the file without closing the stream you will get an IOException.
System.IO.IOException: The process cannot access the file 'File Here' because it is being used by another process..
and example of what could be causing this
StreamReader file = new StreamReader(#"C:\trans.txt");
file.ReadToEnd();
File.Delete(#"C:\trans.txt");
I was loading a Bitmap Image from a File. When I tried to save the Image to another file I got the following error "A generic error occurred in GDI+". I believe this is because the file is locked by the image object.
Ok so tried calling the Image.Clone function. This still locks the file.
hmm. Next I try loading a Bitmap Image from a FileStream and load the image into memory so GDI+ doesn't lock the file. This works great except I need to generate thumbnails using Image.GetThumbnailImage method it throws an out of memory exception. Apparently I need to keep the stream open to stop this exception but if I keep the stream open then the file remains locked.
So no good with that method. In the end I created a copy of the file. So now I have 2 versions of the file. 1 I can lock and manipulate in my c# program. This other original file remains unlocked to which I can save modifications to. This has the bonus of allowing me to revert changes even after saving them because I'm manipulating the copy of the file which cant change.
Surely there is a better way of achieving this without having to have 2 versions of the image file. Any ideas?
Well if you're looking for other ways to do what you're asking, I reckon it should work to create a MemoryStream, and read out the FileStream to it, and load the Image from that stream...
var stream = new FileStream("original-image", FileMode.Open);
var bufr = new byte[stream.Length];
stream.Read(bufr, 0, (int)stream.Length);
stream.Dispose();
var memstream = new MemoryStream(bufr);
var image = Image.FromStream(memstream);
Or something prettier to that extent.
Whether or not that's the way you should go about solving that problem, I don't know. :)
I've had a similar problem and wound up fixing it like this.
I have since found an alternative method to clone the image without locking the file. Bob Powell has it all plus more GDI resources.
//open the file
Image i = Image.FromFile(path);
//create temporary
Image t=new Bitmap(i.Width,i.Height);
//get graphics
Graphics g=Graphics.FromImage(t);
//copy original
g.DrawImage(i,0,0);
//close original
i.Dispose();
//Can now save
t.Save(path)
I had a similar problem. But I knew, that I will save the image as a bitmap-file. So I did this:
public void SaveHeightmap(string path)
{
if (File.Exists(path))
{
Bitmap bitmap = new Bitmap(image); //create bitmap from image
image.Dispose(); //delete image, so the file
bitmap.Save(path); //save bitmap
image = (Image) bitmap; //recreate image from bitmap
}
else
//...
}
Sure, thats not the best way, but its working :-)