How to unset an image from a picturebox in c#? - c#

I have a picturebox that is intended to have different kinds of images based on the situation. On the other way around, it must have no picture when it's not needed. How to unset an image from that picturebox in c#?

Use the Image property to set the image to display.
Set it to null to display nothing.

You can use pictureBox1.Image = null; to accomplish that.

Related

Adding image to rtf doc being resized

We're using migradoc api to create an rtf document.. intermittently when we add an image it;s being resized and coming out absolutely tiny.
Code sample as follows:
MigraDoc.DocumentObjectModel.Shapes.Image image = section.AddImage(imagePath);
image.WrapFormat.Style = MigraDoc.DocumentObjectModel.Shapes.WrapStyle.Through;
If I set LockAspectRatio to true and set a width it does stop is from rendering very small but ideally would like to be able to set a MaxWidth.
Has anyone experiences similar issue?
You have a choice of either changing the image itself by storing a different DPI value in it.
The .Net command to do so with a Bitmap bmp is:
bmp.SetResolution(newHRes , newVRes);
This should not involve reencoding, but I'm not sure.
However you also can simply set the desired DPI value in the Migradoc Image by using its Image.Resolution Property, which
Gets or sets a user defined resolution for the image in dots per inch.
I am not familiar with it at all but I found this code that might help you :
image.RelativeVertical = RelativeVertical.Page;
image.RelativeHorizontal = RelativeHorizontal.Page;

RichTextBox doesn't appear when content is exported as Image

I have a Panel where the contents are added dynamically and exported as an image file. I export the content as image using the following code below.
Bitmap tempBmp = new Bitmap(pnlCanvas.Width, pnlCanvas.Height);
pnlCanvas.DrawToBitmap(tempBmp, new Rectangle(0, 0, pnlCanvas.Width, pnlCanvas.Height));
tempBmp.Save(fileName);
In a particular case i have a RichTextBox control added to the panel. I found that the control is not seen when exported.
I am not sure what goes wrong. Please guide me what should be done.
Thanks in Advance,
K
As it is stated MSDN DrawToBitmap doesn't work with RichTextBox. Try painting the content using GDI+ manually.
Check if the control is actually there, is it disposed or just invisible. Try adding some value to it and check if it returns the value with variable or gives you error (if it's gone). That's my ideas :)
Just succeeded with exactly what i was looking for. I am answering my own question so that it could help someone looking for the same.
Sample code to capture the ActiveX controls and Export as Image.
Rectangle ctrlRect = myControl.RectangleToScreen(myControl.ClientRectangle);
Bitmap myImage = new Bitmap(ctrlRect.Width,ctrlRect.Height,PixelFormat.Format32bppArgb);
Graphics myGraphics = Graphics.FromImage(myImage);
myGraphics.CopyFromScreen(ctrlRect.Location, Point.Empty, myControl.Size);
myImage.Save("sample.png");

Save as a image all the content of a grid

So, I'm trying to save an canvas content as an image. I'm using this for it:
var img = new WriteableBitmap(myCanvas, null);
Problem is that the image is not showing all the content inside of the canvas. If there's a button, an image or other similar objects, they do not show.
I can see an ellipse, but if I set an image as background, the background stays empty.
Is there anyway to solve this?
Try to use Image Tools from codeplex and read this and this

C# how to get a bitmap from a picturebox

I have a image in picturebox. I want to get that image as a Bitmap.
My one line code is:
Bitmap default_image = (Bitmap)pictureBox5.Image.Clone();
But what i am getting is:
default_image value=null;
Can anyone help me.
Bitmap default_image = new Bitmap(pictureBox5.Image);
You are never instantiating a Bitmap which is why it is null.
If you got the image into the PictureBox by using imageLocation
pbSourceImage.ImageLocation = openFile.FileName;
then PictureBox.Image will be null.
Instead, load the picture using
pbSourceImage.Image = Image.FromFile(openFile.FileName);
Then you will be able to clone from the Image property.
This is because you do not have image, probably you have BackgroundImage.
You need to have Image properties fill with your picture.

c# picturebox bitmaps

I have a picturebox that upon request, I save the current display to a bitmap.
My question is, how do I then load that same bitmap to the picturebox?
Thanks.
EDIT:
The only relevant code is:
pictureBox1.DrawToBitmap(test1,pictureBox1.ClientRectangle);
The picture box contains graphics that I have written 'freehand' using the mouse. So you can use the mouse to write directly onto the screen when the left mouse is pressed.
You can assign any image to the picture box that you want during run-time. Just set the Image property of the picture box to the picture you want to be displayed.
For example, to display an image in a picture box from a file on your hard drive, you could use something like:
myPicBox.Image = Image.FromFile("C:\savedimage.bmp");
Or, your edit suggests that you have a bitmap object in memory that you want to display in the picture box. In that case, it's a simple matter of assigning that bitmap object to the Image property:
myPicBox.Image = test1; //(where test1 is your bitmap object in memory)
Edit: Just in case you want to save the bitmap object that you created in memory to disk so that you can reload and use it later, check out the Save method of the Bitmap object:
test1.Save("C:\savedimage.bmp", System.Drawing.Imaging.ImageFormat.Bmp);
If I'm not mistaken, the picturebox should have an Image property that you can simply use to assign the Bitmap to.

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