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How to clear a pictureBox in C#? I have tried setting the property to null but it doesnt work

I would like to clear a pictureBox after clicking on an 'Encode' button to save it as a new image file in my project. I would like to clear the fields on the form after the user saves the image file.
The code I use to display image on pictureBox:
private void btnOpenfile_Click(object sender, EventArgs e)
{
// open file dialog
OpenFileDialog open = new OpenFileDialog();
// image filters
open.Filter = "Image Files (*.png)|*.png";
if (open.ShowDialog() == DialogResult.OK)
{
// display image in picture box
pictureBox1.Image = new Bitmap(open.FileName);
pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
tbFilepath.Text = open.FileName;
//pictureBox1.ImageLocation = tbFilepath.Text;
}
}
The code I used to clear the pictureBox:
private void clearForm()
{
pictureBox1.Image = null; //doesn't work
pictureBox1.Invalidate(); //doesn't work
tbFilepath.Text = "";
tbMessage.Text = "";
}
I have also tried the following but it did not work either:
private void clearForm()
{
Bitmap bm = new Bitmap(img);
bm.Save(tbFilepath.Text,System.Drawing.Imaging.ImageFormat.Png);
}
I tried using the Refresh() method as one of the commentors suggested, but it did not work either:
private void clearForm()
{
Refresh(); //first attempt
pictureBox1.Refresh();// second attempt
}
I expect the pictureBox field to clear out the existing image I have selected but the image did not clear away.
Before clicking on encode button
After clicking on encode button, the textBox fields are cleared but not the pictureBox field. I used the codes I have added in this question.

Try creating a new Bitmap Variable and use it for the picturebox:
Bitmap bitmap = new Bitmap(pictureBox.Width, pictureBox.Height);
pictureBox.Image = bitmap;
pictrueBox.Invalidate();
Also, try to declare a Global Variable for the Bitmap so it is the one to be set as the picture and also the one to be cleared before setting it as the image for the PictureBox.
On the other hand you could try using the OnPaint Method of the Picurebox:
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
bm = new Bitmap(pictureBox1.Width, pictureBox1.Height);
}
Bitmap bm = null;
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
pictureBox1.Image = bm;
}
private void btn_Open_Click(object sender, EventArgs e)
{
OpenFileDialog ofd = new OpenFileDialog();
ofd.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp); *.PNG|*.jpg; *.jpeg; *.gif; *.bmp; *.PNG";
if (ofd.ShowDialog() == DialogResult.OK)
{
bm = new Bitmap(Image.FromFile(ofd.FileName), new Size(pictureBox1.Width, pictureBox1.Height));
textBox1.Text = ofd.FileName;
pictureBox1.Invalidate();
}
}
private void btn_Clear_Click(object sender, EventArgs e)
{
bm = null;
pictureBox1.Invalidate();
}
These code I made worked perfectly. So please try it.

PhotoChooserTask how to pass extra parameter Windows Phone

Say I have this code
private void photoChooserBtn_Click(object sender, RoutedEventArgs e)
{
photoChooserTask = new PhotoChooserTask();
photoChooserTask.Completed += new EventHandler<PhotoResult (photoChooserTask_Completed);
photoChooserTask.Show();
}
private void photoChooserTask_Completed(object sender, PhotoResult e)
{
if (e.TaskResult == TaskResult.OK)
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(e.ChosenPhoto);
imagecontrol.Source = bmp;
}
}
I have to repeat this code several times as I have several buttons. I want to avoid this.
I want to have one button click event. Then append extra parameter to photoChooserTask so that I can process the result in photoChooserTask_Completed event based on the parameter.
So in photoChooserBtn_Click event. I would like to do something like this.
Button btn = (Button)sender;
photoChooserTask.Tag = btn.Name;
Then
private void photoChooserTask_Completed(object sender, PhotoResult e)
{
if (e.TaskResult == TaskResult.OK)
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(e.ChosenPhoto);
imagecontrol.Source = bmp;
string param = ((PhotoChooserTask)sender).Tag;
Switch (param)
{
case "bla":
case "bla2":
...........
}
}
What's the best way to do this?

What you are looking for is not possible. However you can add a string tag property to your page. Since only one PhotoChooserTask can run at a time, this approach should be fine.
public partial class MainPage : PhoneApplicationPage
{
string tag;
// Constructor
public MainPage()
{
InitializeComponent();
}
private void photoChooserBtn_Click(object sender, RoutedEventArgs e)
{
photoChooserTask = new PhotoChooserTask();
tag = (sender as Button).Name;
photoChooserTask.Completed += new EventHandler<PhotoResult>(photoChooserTask_Completed);
photoChooserTask.Show();
}
private void photoChooserTask_Completed(object sender, PhotoResult e)
{
if (e.TaskResult == TaskResult.OK)
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(e.ChosenPhoto);
imagecontrol.Source = bmp;
switch(tag)
{
case tag1:
case tag2:
........
}
tag = null;
}
}

Saving image in picture box to specific directory

I am trying to save webcam image in directory using AForge.NET.
Here is my Code:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
FilterInfoCollection webcam;
VideoCaptureDevice cam;
Bitmap bitmap;
private void Form1_Load(object sender, EventArgs e)
{
webcam = new FilterInfoCollection(FilterCategory.VideoInputDevice);
cam = new VideoCaptureDevice(webcam[0].MonikerString);
cam.NewFrame += new NewFrameEventHandler(cam_NewFrame);
cam.Start();
}
void cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
bitmap = (Bitmap)eventArgs.Frame.Clone();
pictureBox1.Image = bitmap;
pictureBox1.Image.Save("c:\\image\\image1.jpg");
}
But i am getting this exception:
InvalidOperationException was unhandled
Object is currently in use elsewhere.
If you are using Graphic objects after the GetHdc method, call the RealseHdc method.
Thanks in advance.

Problem is this line:
pictureBox1.Image = bitmap;
pictureBox1.Image.Save("c:\\image\\image1.jpg");
You are trying to save image that is not yet properly loaded and also you are facing cross-threading.
The solution in this case is to not use multiple threads when drawing.
void cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
bitmap = (Bitmap)eventArgs.Frame.Clone();
pictureBox1.Image = bitmap;
try
{
this.Invoke((MethodInvoker)delegate
{
//saves image on its thread
pictureBox1.Image.Save("c:\\image\\image1.jpg");
});
}
catch (Exception ex)
{
MessageBox.Show(""+ex);
}
}

C# save bitmap output

I'm creating a C# program that's capturing the screen with bitmap.
And than I want to save it to an .Avi/ .mpeg file.
But I don't know how to save it to a video.
Here is the code I already have.
public Form1()
{
InitializeComponent();
}
static Bitmap bm;
private void btnFolder_Click(object sender, EventArgs e)
{
FolderBrowserDialog folderDlg = new FolderBrowserDialog();
folderDlg.ShowNewFolderButton = true;
DialogResult result = folderDlg.ShowDialog();
if (result == DialogResult.OK)
{
textBox1.Text = folderDlg.SelectedPath;
Environment.SpecialFolder root = folderDlg.RootFolder;
}
}
private void btnStart_Click(object sender, EventArgs e)
{
timer1.Start();
}
private void btnStop_Click(object sender, EventArgs e)
{
timer1.Stop();
SaveCapture(textBox1.Text);
}
private void SaveCapture(string path)
{
// Here should be the code to save it to mpeg/avi
}
private void timer1_Tick(object sender, EventArgs e)
{
// Take screenshot
bm = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);
Graphics graphics = Graphics.FromImage(bm as Image);
graphics.CopyFromScreen(0, 0, 0, 0, bm.Size);
pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
// Show it in picturebox
pictureBox1.Image = bm;
}
Thank you very much!

Create a Video Stream (AVI) from a Series of Images
I think this might be your best solution. Store all the .jpg's and create an avi from the command line at intervals. I don't see how creating video on the fly would produce a "lightweight" solution.

Hello click this to download the aviwrapper liblary. And the code that you should write is this:
var pngFileList = Directory.EnumerateFiles(folderImages, "*.png");
//load the first image
Bitmap bitmap = (Bitmap)Image.FromFile(pngFileList.First());
//create a new AVI file
AviManager aviManager = new AviManager(fileName, false); // location and the name of video file
//add a new video stream and one frame to the new file
//set IsCompressed = false
VideoStream aviStream = aviManager.AddVideoStream(false, 3, bitmap);
pngFileList.Skip(1).ToList().ForEach(file =>
{
bitmap = (Bitmap)Bitmap.FromFile(file);
aviStream.AddFrame(bitmap);
bitmap.Dispose();
});
aviManager.Close();

How do I get an image to save after rotation at runtime?

I am working with WPF and I have an application that the user loads an image file into a RichTextBox and they can rotate the image and print it. I am not sure as to why the image after it has been rotated will not print as it is displayed on the screen. Instead it prints the original. I am new to this so any help would be greatly appreciated!
The following is the code for my application. Code when the retrieve file Button is clicked:
private void retrieve_button_Click(object sender, RoutedEventArgs e)
{
//Retrieve the file or image you are looking for
OpenFileDialog of = new OpenFileDialog();
of.Filter = "Formats|*.jpg;*.png;*.bmp;*.gif;*.ico;*.txt|JPG Image|*.jpg|BMP image|*.bmp|PNG image|*.png|GIF Image|*.gif|Icon|*.ico|Text File|*.txt";
var dialogResult = of.ShowDialog();
if (dialogResult == System.Windows.Forms.DialogResult.OK)
{
try
{
System.Windows.Controls.RichTextBox myRTB = new System.Windows.Controls.RichTextBox();
{
Run myRun = new Run();
System.Windows.Controls.Image MyImage = new System.Windows.Controls.Image();
MyImage.Source = new BitmapImage(new Uri(of.FileName, UriKind.RelativeOrAbsolute));
InlineUIContainer MyUI = new InlineUIContainer();
MyUI.Child = MyImage;
rotateright_button.IsEnabled = true;
print_button.IsEnabled = true;
Paragraph paragraph = new Paragraph();
paragraph.Inlines.Add(myRun);
paragraph.Inlines.Add(MyUI);
FlowDocument document = new FlowDocument(paragraph);
richTextBox.Document = document;
}
}
catch (ArgumentException)
{
System.Windows.Forms.MessageBox.Show("Invalid File");
}
}
}
When the rotate right button is clicked the following code is executed:
RotateTransform cwRotateTransform;
private void rotateright_button_Click(object sender, RoutedEventArgs e)
{
richTextBox.LayoutTransform = cwRotateTransform;
if (cwRotateTransform == null)
{
cwRotateTransform = new RotateTransform();
}
if (cwRotateTransform.Angle == 360)
{
cwRotateTransform.Angle = 0;
}
else
{
cwRotateTransform.Angle += 90;
}
}
After the Image has been loaded and rotated the user can use the following code to print:
private void InvokePrint(object sender, RoutedEventArgs e)
{
System.Windows.Controls.PrintDialog printDialog = new System.Windows.Controls.PrintDialog();
if ((bool)printDialog.ShowDialog().GetValueOrDefault())
{
FlowDocument flowDocument = new FlowDocument();
flowDocument = richTextBox.Document;
flowDocument.ColumnWidth = printDialog.PrintableAreaWidth;
flowDocument.PagePadding = new Thickness(65);
IDocumentPaginatorSource iDocPag = flowDocument;
printDialog.PrintDocument(iDocPag.DocumentPaginator, "Print Document");
}
}

Try this (substitute yourImageControl in the first line, specify which RotateFlipType you want and be sure to reference the System.Drawing dll):
System.Drawing.Bitmap bitmap = BitmapSourceToBitmap((BitmapSource)YourImageControl.Source);
bitmap.RotateFlip(System.Drawing.RotateFlipType.Rotate90FlipNone);
public static System.Drawing.Bitmap BitmapSourceToBitmap(BitmapSource bitmapsource)
{
System.Drawing.Bitmap bitmap;
using (MemoryStream outStream = new MemoryStream())
{
BitmapEncoder enc = new BmpBitmapEncoder();
enc.Frames.Add(BitmapFrame.Create(bitmapsource));
enc.Save(outStream);
bitmap = new System.Drawing.Bitmap(outStream);
}
return bitmap;
}
Another option for conversion...
P.S. You would get a better answer in less time if you posted some code and told us more about what you have tried.