How to Draw a given Character in exact height?

问题

I am drawing the text using Graphics.DrawString() method, But the text height drawn is not same as which i gave.

For Eg:

Font F=new Font("Arial", 1f,GraphicUnit.Inch);
g.DrawString("M", F,Brushes.red,new Point(0,0));

By using the above code, i'm drawing the text with height 1 inch, but the text drawn is not exactly in 1 inch.

I need to Draw the text in Exact height which i'm giving. Thanks in advance..

回答1:

The simplest solution will be to use a GraphicsPath. Here are the steps necessary:

Calculate the height you want in pixels: To get 1.0f inches at, say 150 dpi you need 150 pixels.
Then create a GraphicsPath and add the character or string in the font and font style you want to use, using the calculated height
Now measure the resulting height, using GetBounds.
Then scale the height up to the necessary number of pixels
Finally clear the path and add the string again with the new height
Now you can use FillPath to output the pixels..

Here is a code example. It writes the test string to a file. If you want to write it to a printer or a control using their Graphics objects, you can do it the same way; just get/set the dpi before you calculate the first estimate of the height..

The code below creates this file; the Consolas 'x' is 150 pixels tall as is the 2nd character (ox95) from the Wingdings font. (Note that I did not center the output):

// we are using these test data:
int Dpi = 150;
float targetHeight = 1.00f;
FontFamily ff = new FontFamily("Consolas");
int fs = (int) FontStyle.Regular;
string targetString = "X";

// this would be the height without the white space
int targetPixels = (int) targetHeight * Dpi;

// we write to a Btimpap. I make it large enough..
// Instead you can write to a printer or a Control surface..
using (Bitmap bmp = new Bitmap(targetPixels * 2, targetPixels * 2))
{
    // either set the resolution here
    // or get and use it above from the Graphics!
    bmp.SetResolution(Dpi, Dpi);
    using (Graphics G = Graphics.FromImage(bmp))
    {
        // good quality, please!
        G.SmoothingMode = SmoothingMode.AntiAlias;
        G.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
        // target position (in pixels)
        PointF p0 = new PointF(0, 0);
        GraphicsPath gp = new GraphicsPath();
        // first try:
        gp.AddString(targetString, ff, fs, targetPixels, p0,
                     StringFormat.GenericDefault);
        // this is the 1st result
        RectangleF gbBounds = gp.GetBounds();
        // now we correct the height:
        float tSize = targetPixels * targetPixels / gbBounds.Height;
        // and if needed the location:
        p0 = new PointF(p0.X  - gbBounds.X, p0.X - gbBounds.Y);
        // and retry
        gp.Reset();
        gp.AddString(targetString, ff, fs, tSize, p0, StringFormat.GenericDefault);
        // this should be good
        G.Clear(Color.White);
        G.FillPath(Brushes.Black, gp);
    }
    //now we save the image 
    bmp.Save("D:\\testString.png", ImageFormat.Png);
}

You may want to try using the correction factor to scale up a Font size and use DrawString after all.

There is also a way to calculate the numbers ahead using FontMetrics, but I understand the link to mean that such an approach could be font-dependent..

来源：https://stackoverflow.com/questions/28893445/how-to-draw-a-given-character-in-exact-height

标签

graphics