CODEWITHSUNDEEP
c#imagevisual-studio
Ladessa
Ladessa

Reputation: 1003

C# - Resize Image after upload

I'm trying to resize the image after upload but it doesn't work

What's wrong?

   private void button1_Click(object sender, EventArgs e)
    {
    OpenFileDialog open = new OpenFileDialog(); 

     open.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp"; 
       if (open.ShowDialog() == DialogResult.OK)
    {
        var imagem = new Bitmap(open.FileName);
        var resizedImage = new Bitmap(imagem, pictureBox1.Size);
       pictureBox1.Image = resizedImage;
        } 

 }

Upvotes: 0

Views: 807

Answers (3)

Tony Hopkinson
Tony Hopkinson

Reputation: 20330

Well you don't need this code, just set the SizeMode Property to StretchImage. However the extremely irritating reason your code doesn't work, is changing from one image to another does not in and of itself trigger the picture box to redraw.

The two usual solutions are to either

Call pictureBox1.Invalidate() after you assign the image, or do pictureBox1.Image = null, before you assign it.

You might have to do one of these even with SizeMode set, if the image is the same size as the PictureBox, can't remember.

Upvotes: 1

musefan
musefan

Reputation: 48435

PictureBox already has the ability to resize an image.

If you are assigning the image using the Image property then you can set the SizeMode property to StretchImage. Which means you code would look like this:

var imagem = new Bitmap(open.FileName);
pictureBox1.Image = imagem;

If you want to assign the image using the BackgroundImage property then you can set the BackgroundImageLayout property to Stretch. Which means you code would look like this:

var imagem = new Bitmap(open.FileName);
pictureBox1.BackgroundImage = imagem;

From personal experience I have found the PictureBox control to be a pain. If you are needing to change or remove the image at any point I always found I needed to explicitly dispose of the image or it gave me memory leaks, and in some cases just plain errors. It is worth noting that when you need to do custom drawing or rendering in WinForms then the Panel control is a much better option. You can draw images onto a Panel too, but depending on your needs, you may be find just using the PictureBox

Upvotes: 3

Scott Chamberlain
Scott Chamberlain

Reputation: 127603

You need to set the SizeMode of your picture box

from the MSDN

By default, in Normal mode, the Image is positioned in the upper-left corner of the PictureBox, and any part of the image that is too big for the PictureBox is clipped. Using the StretchImage value causes the image to stretch or shrink to fit the PictureBox. Using the Zoom value causes the image to be stretched or shrunk to fit the PictureBox; however, the aspect ratio in the original is maintained.

So change the setting on PictureBox1 from Normal to StretchImage or Zoom depending on which affect you want. It will make it act how you want and you can remove your resize code.

Upvotes: 1

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