dpi

WPF窗体以及内部的所有元素都是采用设备无关的单位来衡量的。一个设备无关单位定义为1英寸的96分之一，即1/96 inch。 假定我们创建了一个WPF按钮，其大小为96x96个单位，如果使用标准Windows的DPI设置（96dpi），那么每个单位对应的大小为一个真实世界的物理像素。计算公式如下： 物理单位大小 = 设备无关单位大小x系统DPI = 1/96 inch x 96 dpi = 1 pixel 对于一个20英寸的显示器，其标准分辨率为1600x1200，那么它的屏幕DPI为： (1600^2+1200^2)^0.5/20=100 在这样的显示器上，一个96x96单位的按钮就会比1英寸要小。同理，15英寸的LCD显示器的DPI大约是85，那上面提到的按钮就要比1英寸大一些。 现在假如我们将系统的DPI设置为120dpi，那么WPF的渲染引擎就的一个设备无关单位就等于1.25个像素（1/96 inch x 120dpi），一个96x96单位的按钮实际大小就为120x120个像素。 这里就出现了所谓的“分数”像素，一个绘图点可能会落在显示器的两个像素点之间，这时WPF就会引入抗锯齿机制（antialias）。 转载于:https://www.cnblogs.com/SpadeQ/archive/2008/06/23/1228433.html 来源： https://blog

I'm working on a kind of unique app which needs to generate images at specific resolutions according to the device they are displayed on. So the output is different on a regular Windows browser (96ppi), iPhone (163ppi), Android G1 (180ppi), and other devices. I'm wondering if there's a way to detect this automatically. My initial research seems to say no. The only suggestion I've seen is to make an element whose width is specified as "1in" in CSS, then check its offsetWidth (see also How to access screen display’s DPI settings via javascript? ). Makes sense, but iPhone is lying to me with that

There is setting for Display in Windows 7 (Control Panel -> Display). It allows to change the size of the text and other items on the screen. I need to get this setting to be able to switch on/switch off some functionality in my C# application based on the setting value. Is that possible? This setting is the screen DPI, or dots per inch. Read it like so: float dpiX, dpiY; Graphics graphics = this.CreateGraphics(); dpiX = graphics.DpiX; dpiY = graphics.DpiY; I don't think it's possible at the moment for the X and Y values to be different. A value of 96 corresponds to 100% font scaling (smaller)