label2.Font =

Hi hikanagu,

In your last reply, you want to know why there is a display difference of the text when you are using the samefont sizes (expressed in pixels)between 96 DPI and 120 DPI. I can give you a simple explanation below:

DPI means dots per inch. The actual size you can see is in points (1/72 inch), but you used pixels to measure the font, so the actual size will become smaller as DPI increases. The relation between points and pixels is below:
sizeInPixels = (sizeInPoints * dpi)/72 .

I suggest using points instead of pixels, like the codebelow:

float fontSizeInPixelsInDPI96 = 16f; // the font size in pixels

float newFontSizeInPoints = fontSizeInPixelsInDPI96 * 72f / 96; // calculate the size in points

//change the font using the new size in points

this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif",

newFontSizeInPoints, System.Drawing.GraphicsUnit.Point);

You can find detail information in Chapter 16 of the book Addison Wesley Windows Forms 2.0 Programming, which is written by ChrisSells, MichaelWeinhardt.

Below isan extract from the book whichdiscusses about the font size:

A font is an instance of the System.Drawing.Font class, which for each font includes a family, a style, and a size. And, as you might expect, a font family is an instance of the FontFamily class, which encapsulates a group of typefaces that differ only in style. A typeface is a named collection of drawing strokes that make up the outlines of the characters, such as those you're reading right now. It's the typeface name that you're used to seeing in the "Font" menu of most programs. The font style constitutes the variations within a typeface, such as bold, italics, underline, and size. So, a typeface would be Arial, a font family would include Arial Regular and Arial Bold, and a font would be 12-point Arial Bold.

Fonts can be measured in several sizes other than points, including pixels, ems, and design units. A pixel is a point of light on a screen or a point of ink on a printer. Pixels are often packed into inches for measurement. For example, the resolution of video display adapters and printers is typically specified in dots per inch (dpi), where a dot is the same as a pixel. Pixels are device-dependent, so a pixel on a 72-dpi display bears no size relationship to a pixel on a 300-dpi printer.

A point, on the other hand, is inch no matter what device it's drawn on, and the Graphics object scales appropriately as text is drawn. If you want to ensure that a font is rendered to the target device in the correct size, you need to convert between points and pixels. This requires knowing the dpi of the device you're drawing on, which is conveniently available via the Graphics.DpiY property:[1]

[1] There's also a Graphics.DpiX property, but that's used for measuring width and is not useful as related to font height.

using( Graphics g = this.CreateGraphics() ) {

// A 12-point font is 16 pixels high on a 96-dpi monitor

float dpi = g.DpiY;

float points = 12f;

float pixels = (points * dpi)/72f; //=16f

...

}

The em unit of measure is so named because metal typesetters used uppercase M as the guide against which all other letters were measured. M was used because it took up the most vertical and horizontal space. Consequently, the number of points specified for a font represents "one em" for that font.

Finally, design units are a font designer's way to specify a font family's dimensions regardless of the resolution of the rendering device or the size of the rendered font. For example, Arial has a height of 2,048 design units. The design units are used to scale a font family to a point size when individual strokes of the font are rendered (more on this later).

Let me know if this helps.
Aland Li

Hi hikanagu,

In your last reply, you want to know why there is a display difference of the text when you are using the samefont sizes (expressed in pixels)between 96 DPI and 120 DPI. I can give you a simple explanation below:

DPI means dots per inch. The actual size you can see is in points (1/72 inch), but you used pixels to measure the font, so the actual size will become smaller as DPI increases. The relation between points and pixels is below:
sizeInPixels = (sizeInPoints * dpi)/72 .

I suggest using points instead of pixels, like the codebelow:

float fontSizeInPixelsInDPI96 = 16f; // the font size in pixels

float newFontSizeInPoints = fontSizeInPixelsInDPI96 * 72f / 96; // calculate the size in points

//change the font using the new size in points

this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif",

newFontSizeInPoints, System.Drawing.GraphicsUnit.Point);

You can find detail information in Chapter 16 of the book Addison Wesley Windows Forms 2.0 Programming, which is written by ChrisSells, MichaelWeinhardt.

Below isan extract from the book whichdiscusses about the font size:

A font is an instance of the System.Drawing.Font class, which for each font includes a family, a style, and a size. And, as you might expect, a font family is an instance of the FontFamily class, which encapsulates a group of typefaces that differ only in style. A typeface is a named collection of drawing strokes that make up the outlines of the characters, such as those you're reading right now. It's the typeface name that you're used to seeing in the "Font" menu of most programs. The font style constitutes the variations within a typeface, such as bold, italics, underline, and size. So, a typeface would be Arial, a font family would include Arial Regular and Arial Bold, and a font would be 12-point Arial Bold.

Fonts can be measured in several sizes other than points, including pixels, ems, and design units. A pixel is a point of light on a screen or a point of ink on a printer. Pixels are often packed into inches for measurement. For example, the resolution of video display adapters and printers is typically specified in dots per inch (dpi), where a dot is the same as a pixel. Pixels are device-dependent, so a pixel on a 72-dpi display bears no size relationship to a pixel on a 300-dpi printer.

A point, on the other hand, is inch no matter what device it's drawn on, and the Graphics object scales appropriately as text is drawn. If you want to ensure that a font is rendered to the target device in the correct size, you need to convert between points and pixels. This requires knowing the dpi of the device you're drawing on, which is conveniently available via the Graphics.DpiY property:[1]

[1] There's also a Graphics.DpiX property, but that's used for measuring width and is not useful as related to font height.

using( Graphics g = this.CreateGraphics() ) {

// A 12-point font is 16 pixels high on a 96-dpi monitor

float dpi = g.DpiY;

float points = 12f;

float pixels = (points * dpi)/72f; //=16f

...

}

The em unit of measure is so named because metal typesetters used uppercase M as the guide against which all other letters were measured. M was used because it took up the most vertical and horizontal space. Consequently, the number of points specified for a font represents "one em" for that font.

Finally, design units are a font designer's way to specify a font family's dimensions regardless of the resolution of the rendering device or the size of the rendered font. For example, Arial has a height of 2,048 design units. The design units are used to scale a font family to a point size when individual strokes of the font are rendered (more on this later).

Let me know if this helps.
Aland Li