Hi Team, How to increase the white dots sizes? Please refer the attached image. <img src="https://learn-attachment.microsoft.com/api/attachments/256917-myimage.png?platform=QnA" alt="using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; static void Main(string[] args) { //Image image = new Bitmap(1000, 1000, PixelFormat.Format32bppArgb); Bitmap bitmap = new Bitmap(100, 100, System.Drawing.Imaging.PixelFormat.Format32bppPArgb); Graphics graph = Graphics.FromImage(bitmap); Pen pen = new Pen(Brushes.Green); Rectangle rect = new Rectangle(0, 0, 100, 100); graph.DrawRectangle(pen, rect); Brush b = new HatchBrush(HatchStyle.Percent90, Color.Orange, Color.White); // Fill rectangle to screen. graph.FillRectangle(b, rect); bitmap.Save("myImage.png", System.Drawing.Imaging.ImageFormat.Png); }" />

Increase Dots size in rectangle.

Shashank Sivakoti 1

Hi Team,

How to increase the white dots sizes? Please refer the attached image.

Jiale Xue - MSFT 47,666 Reputation points Microsoft Vendor

2022-12-05T08:44:00.633+00:00

Hi @SrinuNani, Welcome to Q&A. If someone else solves your problem, you could mark it. We don't usually ask multiple questions in one question. If there is a new question, we can ask another one.

1 answer

Viorel 118.5K

I think that you can use a TextureBrush. For example, you can build it dynamically:

Bitmap bitmap = new Bitmap( 100, 100, System.Drawing.Imaging.PixelFormat.Format32bppPArgb );  
  
Graphics graph = Graphics.FromImage( bitmap );  
Rectangle rect = new Rectangle( 0, 0, 100, 100 );  
  
using( var img = new Bitmap( 8, 8, graph ) )  
{  
    using( var g = Graphics.FromImage( img ) )  
    {  
        g.Clear( Color.Orange );  
        g.FillRectangle( Brushes.White, 0, 6, 2, 2 );  
        g.FillRectangle( Brushes.White, 4, 3, 2, 2 );  
    }  
  
    var tb = new TextureBrush( img );  
  
    graph.FillRectangle( tb, rect );  
}  
  
bitmap.Save( "myImage.png", System.Drawing.Imaging.ImageFormat.Png );

You can load the texture brush from an existing image too, made by a Graphical Editor or Visual Studio, saved as a file or embedded resource.

It is also possible to scale it using tb.ScaleTransform.

Shashank Sivakoti 1

Hi, I am able to generate image but white dots are coming in square, can we change it to circles?

Bitmap bitmap = new Bitmap(100, 100, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);

        Graphics graph = Graphics.FromImage(bitmap);  
        Rectangle rect = new Rectangle(0, 0, 100, 100);  

        using (var img = new Bitmap(8, 8, graph))  
        {  
            using (var g = Graphics.FromImage(img))  
            {  
                g.Clear(Color.Orange);  
                g.FillRectangle(Brushes.White, 0, 6, 2, 2);  
                g.FillRectangle(Brushes.White, 4, 3, 2, 2);  
            }  

            var tb = new TextureBrush(img);  
            tb.ScaleTransform(3, 3);  
            graph.FillRectangle(tb, rect);  
        }  

        bitmap.Save("myImage.png", System.Drawing.Imaging.ImageFormat.Png);

Viorel 118.5K

Try FillEllipse:

Bitmap bitmap = new Bitmap( 100, 100, System.Drawing.Imaging.PixelFormat.Format32bppPArgb );  
  
Graphics graph = Graphics.FromImage( bitmap );  
Rectangle rect = new Rectangle( 0, 0, 100, 100 );  
  
using( var img = new Bitmap( 24, 24, graph ) )  
{  
    using( var g = Graphics.FromImage( img ) )  
    {  
        g.Clear( Color.Orange );  
        g.PixelOffsetMode = PixelOffsetMode.HighQuality;  
        g.SmoothingMode = SmoothingMode.HighQuality;  
        g.FillEllipse( Brushes.White, 0, 14, 9, 9 );  
        g.FillEllipse( Brushes.White, 12, 3, 9, 9 );  
    }  
  
    var tb = new TextureBrush( img );  
  
    graph.FillRectangle( tb, rect );  
}  
  
bitmap.Save( "myImage.png", System.Drawing.Imaging.ImageFormat.Png );

Shashank Sivakoti 1 Reputation point

2022-11-04T15:38:24.28+00:00

Thank You Viorel, issue is resolved, can we convert this image into base64 string (without saving image can we convert and return string)? I want to convert into base64 string and upload this in RedisCache.

Viorel 118.5K

There are various example of conversion. Try this fragment too:

// . . .  
  
string base64;  
  
using( var ms = new MemoryStream())  
{  
    bitmap.Save( ms, System.Drawing.Imaging.ImageFormat.Png );  
    base64 = Convert.ToBase64String( ms.GetBuffer( ), 0, checked((int)ms.Length) );  
}

But it is probably advisable to present the new questions separately.

Shashank Sivakoti 1 Reputation point

2022-11-07T18:24:45.227+00:00

How to add the border color for the rectangle and width of the border?
Shashank Sivakoti 1 Reputation point

2022-11-08T06:47:47.27+00:00

Hi Viorel-1,

I am using .Net 6 and in API I am generating image in below line one exception is coming.

Line: Bitmap bitmap = new Bitmap(100, 100, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);

Exception: System.PlatformNotSupportedException: 'System.Drawing.Common is not supported on this platform.'

How to generate this image in .Net 6

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Increase Dots size in rectangle.

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