CODEWITHSUNDEEP
c#winformsbitmapresolution
ApachePilotMPE
ApachePilotMPE

Reputation: 193

Rather small bitmap returns invalid parameters

EDIT - Solved?

After restarting VS... The exception seems to have COMPLETELY dissappeared. It just doesn't occur anymore. Sooo... Problem solved? I suppose?

OP

In my application, I am trying to create a bitmap of size 1366 x 706. However, when I attempt to paint it onto my form, it returns a "parameter is not valid" exception.

After reading up, I learned that the parameter error usually means that C# won't allocate enough memory for the bitmap. However, 1366x706 doesn't seem to be that large of a resolution.

On disk, a 1366x706 image only takes up 2.5MB. Is that too large for WinForms to handle?

EDIT

Code:

// These variables vary based on the size of the winform, these values return the error 
float resizeFactorX = 4.553333f;
float resizeFactorY = 2.353333f;

// The original size of the image is ALWAYS 300x300, that never changes
public static Image resizeImageByFactors(Image i, float resizeFactorX, float resizeFactorY)
{
    Bitmap bitmap1 = new Bitmap((int)((float)(i.Width) * resizeFactorX), (int)((float)(i.Height * resizeFactorY)));
    using (var gr = Graphics.FromImage(bitmap1))
    {
        gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
        gr.DrawImage(i, new Rectangle(Point.Empty, new Size(bitmap1.Width, bitmap1.Height)));
    }
    return bitmap1;
}

If you need any more information, don't hesitate to let me know.

EDIT 2

The error is also produced anytime the resize factors are not equal to 1.0.

Stack Trace:

System.ArgumentException: Parameter is not valid.
at System.Drawing.Bitmap..ctor(Int32 width, Int32 height, PixelFormat format)
at System.Drawing.Bitmap..ctor(Int32 width, Int32 height)
at Paint_Test.Form1.resizeImageByFactors(Image i, Single resizeFactorX, Single     resizeFactorY) in c:\Users\ApachePilotMPE\Documents\Visual Studio 2012\Projects\Paint     Test\Paint Test\Form1.cs:line 273

Upvotes: 2

Views: 696

Answers (1)

Pedro77
Pedro77

Reputation: 5294

"Either way, the posted code doesn't produce the error for your audience. Either the numbers are out of whack or your image isn't valid. Something we can't see. – LarsTech"

Well, it seems that your error have nothing to do with the code that you have posted here.

I think it is related with how you are calculating the XY resize factors. If you are still doing this:

resizeFactorX = (float)(this.ClientSize.Width / 300.0);

You will get 0 if Width < 300!

As you said:

"I've found that the application throws this error anytime a bitmap larger than the ClientSize of the form is created"

This happens because Width is an int, and you are casting after the int/float division, that results an int. You must cast the int to float BEFORE the division.

Correct way:

resizeFactorX = ((float)this.ClientSize.Width) / 300;

I hope this solves your problem. :)

Upvotes: 1

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