Creating image from text - how to ensure image size is correct based on size of text

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Creating image from text - how to ensure image size is correct based on size of text

Darren Rose 311

Hi

I am using the below example code to create an image from text, which works fine.

But I want to ensure that the size of the image can be determined automatically based on the string provided, the font and the font size, rather than having to stipulate the size.

Any ideas please.

Thanks

Dim bmp As Bitmap = New Bitmap(300, 50)  
  
        Using graphics As Graphics = System.Drawing.Graphics.FromImage(bmp)  
            Dim font As Font = New Font("Lucida Handwriting", 12)  
            graphics.FillRectangle(New SolidBrush(System.Drawing.Color.Transparent), 0, 0, bmp.Width, bmp.Height)  
            graphics.DrawString("Darren Rose", font, New SolidBrush(System.Drawing.Color.Black), 0, 0)  
            graphics.Flush()  
            font.Dispose()  
            graphics.Dispose()  
        End Using

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Answer 1

Castorix31 90,681

You can use Graphics.MeasureString

Darren Rose 311 Reputation points

2022-08-04T16:49:14.037+00:00

Thanks, can't see how to use it in the context I need though, as it appears you can't just use it directly as a command and have to call it and pass PaintEventArgs? even the samples on this page don't work for me - https://learn.microsoft.com/en-us/dotnet/api/system.drawing.graphics.measurestring?view=netframework-4.8 as how do you then call MeasureStringMin - what do you provide as e?

Castorix31 90,681

For example :

        Using gr As Graphics = System.Drawing.Graphics.FromHwnd(IntPtr.Zero)  
            Dim sText As String = "Darren Rose"  
            Using font As Font = New Font("Lucida Handwriting", 12.0F)  
                Dim nSize As SizeF = gr.MeasureString(sText, font)  
                Using bmp As Bitmap = New Bitmap(CInt(nSize.Width), CInt(nSize.Height))  
                    Using graphics As Graphics = System.Drawing.Graphics.FromImage(bmp)  
                        graphics.FillRectangle(New SolidBrush(System.Drawing.Color.Transparent), 0, 0, bmp.Width, bmp.Height)  
                        graphics.DrawString(sText, font, New SolidBrush(System.Drawing.Color.Red), 0, 0)  
                    End Using  
                    bmp.Save("test.png", System.Drawing.Imaging.ImageFormat.Png)  
                End Using  
            End Using  
        End Using

Darren Rose 311 Reputation points

2022-08-05T09:31:35.24+00:00

Thank you @Castorix31 - looks so simple seeing the working code, but for the life of me I couldn't get it to work yesterday - much appreciated :)
Darren Rose 311 Reputation points

2022-08-05T16:17:07.463+00:00

One issue I notice is that the font size specified doesn't seem to have any affect, it doesn't matter what I change it too, the image is always the same size?

Any thoughts please?
Castorix31 90,681 Reputation points

2022-08-05T17:01:57.407+00:00

I cannot reproduce this problem
If I test for example with 12 and 42, I get :
Darren Rose 311 Reputation points

2022-08-05T19:19:01.75+00:00
Very odd, must be something my end.

On separate note, found adding below drastically improves quality of the text

graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias
Darren Rose 311 Reputation points

2022-08-05T19:30:33.547+00:00

The size issue was misleading, it was creating it correctly, just the next part of my code which was inserting it into a PDF was inserting it at a set size so wasn't obvious the underlying image was different, hence my confusion. Time to give up for the day I think!!

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