I already had an image inside PictureBox control, and now I want to pass a new one to it.
What happens, is that allpication Disposes (and I catch an exception: "Parameter is not valid").
This is my code:
using (Image img = Image.FromFile(open.FileName))
{
part.Picture = img;
pictureBox1.InitialImage = null;
pictureBox1.Image = img;
}
So when the code goes out of the method, it goes streight to Displose of this and main form. I catch the exception only on line where Form1 was started. On this one there is no excpetions what so ever.
It must be something wrong while pictureBox is painting (inside Paint event), but I am not surbsribed to it.
I really dont have any more clue how to salve this issue. I have even tried to use to clear all resources (by calling garbage collection), but nothing seems to work.
One more thing: "part" is a reference of the List, so when I try to Delete the current image (to replace it with a new one) I got another exception, like:
"The process cannot access the file because it is being used by another process".
Does this has something to do with the 1st exception (when new image is not painted in pictureBox)?
As Reed noted, the Image you are pulling from open.Filename is being disposed once you exit the using() statement. Your picturebox is still referencing this image in memory, so when it is disposed, you lose what was stored in your picturebox too.
What you really need is a unique copy of the image you are pulling.
using (Image sourceImg = Image.FromFile(open.Filename))
{
Image clonedImg = new Bitmap(sourceImg.Width, sourceImg.Height, PixelFormat.Format32bppArgb);
using (var copy = Graphics.FromImage(clonedImg))
{
copy.DrawImage(sourceImg, 0, 0);
}
pictureBox1.InitialImage = null;
pictureBox1.Image = clonedImg;
}
This way, your file will be unlocked as soon as you exit this block, and you'll keep a unique copy of your image in the picturebox.
The problem is that, after this code executes, pictureBox1.Image is referring to an Image which has been disposed.
If you do not wrap the Image creation in a using, it should correct your issue.
Image img = Image.FromFile(open.FileName);
part.Picture = img;
pictureBox1.InitialImage = null;
pictureBox1.Image = img; // You can't dispose of this, or it won't be valid when PictureBox uses it!
You could also do something like the following create a method that loads the images and then pass it back to the Image Control for example this is what I am using when I want to populate an Image Ctrl
I have a windows form with 3 different Images that I want to load but I am only showing the code for One since I call the same method for all 3 Image Controls
#region Codes for browsing for a picture
/// <summary>
/// this.picStudent the name of the Image Control
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnStudentPic_Click(object sender, EventArgs e)
{
Image picture = (Image)BrowseForPicture();
this.picStudent.Image = picture;
this.picStudent.SizeMode = PictureBoxSizeMode.StretchImage;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
private Bitmap BrowseForPicture()
{
// Bitmap picture = null;
try
{
if (this.fdlgStudentPic.ShowDialog() == DialogResult.OK)
{
byte[] imageBytes = File.ReadAllBytes(this.fdlgStudentPic.FileName);
StudentPic = new Bitmap( this.fdlgStudentPic.FileName);
StuInfo.StudentPic = imageBytes;
}
else
{
StudentPic = Properties.Resources.NoPhotoAvailable;
}
}
catch (Exception)
{
MessageBox.Show("That was not a picture.", "Browse for picture");
StudentPic = this.BrowseForPicture();
}
return StudentPic;
}
#endregion
Yes, this is now working, but strange, I would almost swear I tried this way too.
Ok, never mind, just that it works.
What is troubling me is something else too, which is in my opinion the same as your code, but its not working, its again trying to Dispose application (with same exception).
This is an example code:
using(Image img = Image.FromFile(open.FileName))
{
part.Picture = img;
}
pictureBox1.InitialImage = null;
pictureBox1.Image = part.Picture; //Picture is a propery in a class
Now I pass an actual image into a generic list, and try to assign new image to pictureBox from it, but, again as I said, exception is thrown (and application is terminated).
Why?
Related
public partial class Form1 : Form
{
Image File;
public Form1()
{
InitializeComponent();
}
private void Import_Click(object sender, EventArgs e)
{
OpenFileDialog f = new OpenFileDialog();
f.Filter = "Image files (*.jpg, *.png) | *.jpg; *.png";
if (f.ShowDialog() == DialogResult.OK)
{
File = Image.FromFile(f.FileName);
pictureBox1.Image = File;
}
}
private void Export_Click(object sender, EventArgs e)
{
Bitmap image = new Bitmap(File);
image.SetPixel(50, 50, Color.Black);
SaveFileDialog f = new SaveFileDialog();
f.Filter = "JPG(*.JPG)|*.jpg";
if (f.ShowDialog() == DialogResult.OK)
{
File.Save(f.FileName);
}
}
}
What I want to do is to import an image, change the color of a pixel of it, and export it.
What am I doing wrong?
Thanks in advance.
After Setting color operation, you should set File again with colored object.
That way;
image.SetPixel(50, 50, Color.Red);
File = image;
I hope this works for you! (I coded and it runs correctly for me)
There are actually several issues with your code:
You're not closing the file stream of the image you opened, meaning you will never be able to save the modified image to the same filename. In fact, no program will be able to overwrite the file until your program is closed.
You don't check if the edit is possible; open an image that is less than 51 pixels in either dimension and the save operation will crash.
You're only offering to save as jpeg... a format in which a single pixel change will inevitably be smudged by the compression.
You're not actually saving as jpeg. The default save without specifying a type will make the image end up as png format. It'll just have the wrong file extension.
As ilyas varol pointed out, you're saving the unmodified File instead of the edited image.
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.
To get around the problem of the unclosed stream, you can load the image like this instead:
private void Import_Click(object sender, EventArgs e)
{
OpenFileDialog f = new OpenFileDialog();
f.Filter = "Image files (*.jpg, *.png)|*.jpg;*.png";
if (f.ShowDialog() != DialogResult.OK)
return;
using (Bitmap img = new Bitmap(f.FileName))
{
// if a file was already opened, dispose the old one.
// Start by setting the shown image to null so it
// will never try to show the disposed object.
pictureBox1.Image = null;
if (File != null)
{
try { File.Dispose(); }
catch { /* ignore */ }
}
// Clone loaded image into new object
File = new Bitmap(img);
}
pictureBox1.Image = File;
}
The new Bitmap(image) constructor is one of the few safe ways to make a clone of an image object that's completely disconnected from the original loaded source. It does have the side effect of converting the image to 32-bit colour, if it was in a different colour format before.
There's another issue here, though. In the export function, you are once again making a new Bitmap that you do not dispose. Why do you make that clone? Is there any issue with using File directly? If there isn't, you should just edit it directly, and the pixel change will be shown on the UI as well. If you do want to only apply the change to the saved picture, again, use a using block for the new object, so the image resources in memory are cleaned up automatically afterwards.
Also, you should really only perform the operation once the user has actually confirmed the filename. Your code performs it even if they press "Cancel", because it's performed before you even show the dialog.
private void Export_Click(object sender, EventArgs e)
{
SaveFileDialog f = new SaveFileDialog();
f.Filter = "Png Image (.png)|*.png";
if (f.ShowDialog() != DialogResult.OK)
return;
// OPTION 1: Edit "File" directly:
// Don't edit without doing the necessary checks.
if (File.Width > 50 && File.Height > 50)
File.SetPixel(50, 50, Color.Black);
File.Save(f.FileName, ImageFormat.Png);
// OPTION 2: Edit clone without affecting "File":
using (Bitmap image = new Bitmap(File))
{
// Don't edit without doing the necessary checks.
if (image.Width > 50 && image.Height > 50)
image.SetPixel(50, 50, Color.Black);
image.Save(f.FileName, ImageFormat.Png);
}
}
I'm making a simple Windows Phone 8.1 Silverlight app. The idea is that I can make an entry with a picture (taken with the camera) and add a title and description text to it. Once an entry is saved, a button appears on the main page to view it. So I made 3 entries and they are listed on the main page, but after navigating to their pages a few times, I get a NavigationFailed along with OutOfMemoryException. The pages are simple, they only contain 1 image along with some textblocks.
I thought the issue is that the images are still in memory, that's why I try to set them to null and force the garbage collector, but that didn't help at all. What could cause the OutOfMemory-exception?
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
string id= "";
if (NavigationContext.QueryString.TryGetValue("id", out id))
{
foreach (cEntry entry in helper.entries)
{
if (entry.id.ToString() == id)
{
textBlock_viewText.Text = entry.text;
textBlock_viewTitle.Text = entry.title;
using (IsolatedStorageFile userStore = IsolatedStorageFile.GetUserStoreForApplication())
{
if (userStore.FileExists(entry.imageFileName))
{
using (IsolatedStorageFileStream imgStream = userStore.OpenFile(entry.imageFileName, System.IO.FileMode.Open, System.IO.FileAccess.Read))
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(imgStream);
image_viewEntryImage.Source = bmp;
bmp = null;
}
}
}
}
}
}
}
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
base.OnNavigatedFrom(e);
image_viewEntryImage.Source = null;
GC.Collect();
}
You may need to freeze the BitmapImage.
As described here there is an issue with WPF (the typical framework for Windows Phone development) where BitmapImages can be incorrectly kept alive. While it was supposedly fixed a while back, people have reported still seeing the problem in some cases.
Instead of setting bmp as null try this.
public static void DisposeImage(BitmapImage image)
{
Uri uri= new Uri("oneXone.png", UriKind.Relative);
StreamResourceInfo sr=Application.GetResourceStream(uri);
try
{
using (Stream stream=sr.Stream)
{
image.DecodePixelWidth=1; //This is essential!
image.SetSource(stream);
}
}
catch { }
}
call this method and set source as this custom method after that assing bmp as null.
The GC not able to clear the memory. details are here Why do I get an OutOfMemoryException when I have images in my ListBox?
I was trying to delete an Image from the view Model after some modification but I'm getting this error message IOException was unhandled
I disposed the current bitmap currImgHandler.CurrentBitmap.Dispose();and also made the Image Source to be null ViewedPhoto.Source = null;
if i click on the button which has the Rotate function (90°) once and clikcing on the delete function which produces the error IOException was unhandled
If i clcik on the button Roate function twicethen click on Delete function; I don't get any error and it deletes image without any problem.
What is the mistake am I doing here? Thank you
Selecting an Image from ListView:
private string saveFilname;
private void showImage(object sender, SelectionChangedEventArgs args)
{
ListBox list = ((ListBox)sender);
if (list != null)
{
int index = list.SelectedIndex;
if (index >= 0)
{
ImageFileViewModel image = imageListBox.SelectedItem as ImageFileViewModel;
if ((image != null))
{
saveFilname = image.FileName.ToString();
currImgHandler.CurrentFileHandler.Load(image.FileName);
PaintImage();
}
}
}
}
Delete Function:
private void bDeletePhoto_Click(object sender, RoutedEventArgs e)
{
ImageFileCollectionViewModel viewModel = imageListBox.DataContext as ImageFileCollectionViewModel;
if (viewModel != null)
{
ImageFileViewModel image = imageListBox.SelectedItem as ImageFileViewModel;
if (image != null)
{
//remove physical file from disk:
currImgHandler.CurrentBitmap.Dispose();
ViewedPhoto.Source = null;
File.Delete(image.FileName);
//remove item from ObservableCollection:
viewModel.AllImages.Remove(image);
}
}
}
//Rotate Function:
private void Button_Click(object sender, RoutedEventArgs e)//Rotate
{
currImgHandler.CurrentRotationHandler.Flip(RotateFlipType.Rotate90FlipNone);
PaintImage();
}
private void PaintImage()
{
System.IO.MemoryStream stream = new System.IO.MemoryStream();
currImgHandler.CurrentBitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Bmp);
stream.Position = 0;
byte[] data = new byte[stream.Length];
stream.Read(data, 0, Convert.ToInt32(stream.Length));
BitmapImage bmapImage = new BitmapImage();
bmapImage.BeginInit();
bmapImage.CacheOption = BitmapCacheOption.OnLoad;
bmapImage.StreamSource = stream;
bmapImage.EndInit();
ViewedPhoto.Source = bmapImage; //ImageBox
ViewedPhoto.Stretch = Stretch.Uniform;
}
Error message:
Your application is throwing an IOException. Likely culprit:
File.Delete(image.FileName);
IMO You should avoid making calls like this directly in event handlers for the reason demonstrated here - it is hard to catch exceptions thrown directly from an event handler.
If implementing MVVM this doesn't tend to occur.
Perhaps the account privileges under which your application is running are not sufficient to let you delete the file. Please check the credentials of this account against operations on the file you want to delete.
It's only a supposition though, it's hard to be sure without the IOEXception content, and it could also be because the path you're using doesn't exist, etc...
After Drew Rsuggestion i have added a method in the MVVM itself:
public void RemoveOldPhotoItem(ImageFileViewModel imageFile)
{
this._allImages.Remove(imageFile);
this.DataItemsCount++;
File.Delete(imageFile.FileName);
}
I need to dispose the image which was used by a 3rd party .dll....which i disposed properly.
Sorry guys it was my mistake. Thank you for your support!
I'm trying to get my screen shot image to be displayed in a picture box held on my Control panel form. But the image is not getting passed over.
I have been informed that the issue may be laying within the following lines of code:
ScreenCapture capture = new ScreenCapture();
capture.CaptureImage(showCursor, curSize, curPosition, startPoint, Point.Empty, bounds, _screenPath, fi);
As I'm creating a new screen capture, the data isn't getting passed over to the my picture box. When I run my program the errors originate with the following lines always returning null:
Image img = (Image)bitmap;
if (OnUpdateStatus == null) return;
ProgressEventArgs args = new ProgressEventArgs(img);
OnUpdateStatus(this, args);
Then in my control panel winform I'm trying to display the image as follows:
private ScreenCapture _screenCap;
public ControlPanel()
{
InitializeComponent();
_screenCap = new ScreenCapture();
_screenCap.OnUpdateStatus += _screen_CapOnUpdateStatus;
}
private void _screen_CapOnUpdateStatus(object sender, ProgressEventArgs e)
{
imagePreview.Image = e.CapturedImage;
}
The advice I was given was as follows:
You're looking at the value of OnUpdateStatus within the CaptureImage
method, right? So it matters which instead of ScreenCapture you call
the method on. I suspect you need to pass _screenCap to the
constructor of Form1 (which would need to store it in a field) so that
you could use the same instance when you call CaptureImage within
Form1
I have no idea how to implement the advice that was given to me. In my first two lines of code I simply tried to take away the creation of a new instance of my ScreenCapture class and write
ScreenCapture.CaptureImage(showCursor, curSize, curPosition, startPoint, Point.Empty, bounds, _screenPath, fi);
But this generates the following error:
Error 1 An object reference is required for the non-static field, method, or property 'DotFlickScreenCapture.ScreenCapture.CaptureImage(bool, System.Drawing.Size, System.Drawing.Point, System.Drawing.Point, System.Drawing.Point, System.Drawing.Rectangle, string, string)'
So to get rid of this error I turned the Method being called to a static class but this generated a whole host of different errors with my code trying to store the image taken:
Image img = (Image)bitmap;
if (OnUpdateStatus == null) return;
ProgressEventArgs args = new ProgressEventArgs(img);
OnUpdateStatus(this, args);
It claims that my OnUpdateStatus require an object reference and that using the THIS keyword where I have is not valid in a static field or environment.
Is anyone able to help with getting my image to be displayed in an image box?
Sincerely I could not understand your code. But I understood the advice was given to you. It says that pass the object of captured screen to the form's constructor:
Lets say you have a form name form1. Here is the constructor and little code you must have in the form1 class:
public partial class Form1 : Form
{
Image CapturedImage;
public Form1(Image imgObj) //"you need to pass _screenCap to the constructor of Form1"
{
InitializeComponent();
CapturedImage = imgObj; //"which would need to store it in a field"
}
}
The constructor is taking the captured image as an object(Image imgObj) and assign it to the field(Image CapturedImage;).
If you want to display it in the picturebox. Simply add this line in the constructor as well:
picturebox.Image = CapturedImage;
Now to call it from another form, do it like this:
Capture screen as you are doing (your first code is correct in which you create object of ScreenCapture class) and save it in an object:
Image CapturedImageObj = capture.CaptureImage(showCursor, curSize, curPosition, startPoint, Point.Empty, bounds, _screenPath, fi);
Now create instance of form1 and pass captured image to the constructor of the form:
form1 ImageForm = new form1(CapturedImageObj);
and display it:
form1.Show();
How can I clear draw image on picturebox?
The following doesn't help me:
pictbox.Image = null;
pictbox.Invalidate();
Please help.
EDIT
private void pictbox_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
vl.Draw(g, ref tran.realListForInsert);
}
public void Draw(Graphics g, ref List<double> arr)
{
g.DrawRectangle(new Pen(Brushes.Red, 3), nodeArr[Convert.ToInt32(templstName)].pict.Location.X, nodeArr[Convert.ToInt32(templstName)].pict.Location.Y, 25, 25);
g.DrawRectangle(new Pen(Brushes.Green, 3), nodeArr[Convert.ToInt32(templstArgName)].pict.Location.X, nodeArr[Convert.ToInt32(templstArgName)].pict.Location.Y, 25, 25);
nodeArr[Convert.ToInt32(templstName)].text.Text = arr[Convert.ToInt32(templstArgName)].ToString();
arr[Convert.ToInt32(templstName)] = arr[Convert.ToInt32(templstArgName)];
}
Setting the Image property to null will work just fine. It will clear whatever image is currently displayed in the picture box. Make sure that you've written the code exactly like this:
picBox.Image = null;
As others have said, setting the Image property to null should work.
If it doesn't, it might mean that you used the InitialImage property to display your image. If that's indeed the case, try setting that property to null instead:
pictBox.InitialImage = null;
if (pictureBox1.Image != null)
{
pictureBox1.Image.Dispose();
pictureBox1.Image = null;
}
You need the following:
pictbox.Image = null;
pictbox.update();
private void ClearBtn_Click(object sender, EventArgs e)
{
Studentpicture.Image = null;
}
I assume you want to clear the Images drawn via PictureBox.
This you would be achieved via a Bitmap object and using Graphics object. you might be doing something like
Graphics graphic = Graphics.FromImage(pictbox.Image);
graphic.Clear(Color.Red) //Color to fill the background and reset the box
Is this what you were looking out?
EDIT
Since you are using the paint method this would cause it to be redrawn every time, I would suggest you to set a flag at the formlevel indicating whether it should or not paint the Picturebox
private bool _shouldDraw = true;
public bool ShouldDraw
{
get { return _shouldDraw; }
set { _shouldDraw = value; }
}
In your paint just use
if(ShouldDraw)
//do your stuff
When you click the button set this property to false and you should be fine.
For the Sake of Understanding:
Depending on how you're approaching your objective(s), keep in mind that the developer is responsible to Dispose everything that is no longer being used or necessary.
This means: Everything you've created along with your pictureBox (i.e: Graphics, List; etc) shall be disposed whenever it is no longer necessary.
For Instance:
Let's say you have a Image File Loaded into your PictureBox, and you wish to somehow Delete that file.
If you don't unload the Image File from PictureBox correctly; you won't be able to delete the file, as this will likely throw an Exception saying that the file is being used.
Therefore you'd be required to do something like:
pic_PhotoDisplay.Image.Dispose();
pic_PhotoDisplay.Image = null;
pic_PhotoDisplay.ImageLocation = null;
// Required if you've drawn something in the PictureBox. Just Don't forget to Dispose Graphic.
pic_PhotoDisplay.Update();
// Depending on your approach; Dispose the Graphics with Something Like:
gfx = null;
gfx.Clear();
gfx.Dispose();
Hope this helps you out.
I've had a stubborn image too, that wouldn't go away
by setting the Image and InitialImage to null.
To remove the image from the pictureBox for good, I had to use the code below,
by calling Application.DoEvents() repeatedly:
Application.DoEvents();
if (_pictureBox.Image != null)
_pictureBox.Image.Dispose();
_pictureBox.Image = null;
Application.DoEvents();
if (_pictureBox.InitialImage != null)
_pictureBox.InitialImage.Dispose();
_pictureBox.InitialImage = null;
_pictureBox.Update();
Application.DoEvents();
_pictureBox.Refresh();
I had to add a Refresh() statement after the Image = null to make things work.
I used this method to clear the image from picturebox. It may help some one
private void btnClear1_Click(object sender, EventArgs e)
{
img1.ImageLocation = null;
}
Its so simple!
You can go with your button click event,
I used it with a button property Name: "btnClearImage"
// Note 1a:
// after clearing the picture box
// you can also disable clear button
// by inserting follwoing one line of code:
btnClearImage.Enabled = false
// Note 1b:
// you should set your button Enabled property
// to "False"
// after that you will need to Insert
// the following line to concerned event or button
// that load your image into picturebox1
// code line is as follows:
btnClearImage.Enabled = true;
You should try. When you clear your Graphics you must choose color. SystemColors.Control is native color of form
Graphics g = pB.CreateGraphics();
g.Clear(SystemColors.Control);
clear pictureBox in c# winform Application
Simple way to clear pictureBox in c# winform Application