真正需要DPI意识吗? [英] DPI-awareness is really needed?

问题描述

我正在学习如何使用GDI/GDI +绘制GUI，我发现了这个

I am learning how to draw GUI's with GDI/GDI+, i found this http://msdn.microsoft.com/en-us/library/windows/desktop/dd756596(v=vs.85).aspx#step_2__declare_that_the_application_is_dpi-aware Does every application do that calculation so it can be displayed properly or what ?

有人可以解释如何计算窗口上的按钮，图像和所有控件的客户端坐标，以便它们在不同分辨率下具有相同的对齐方式吗?

Can someone explain how to calculate client coordinates of buttons,images and all controls on your window so they have the same align on different resolutions ?

谢谢.

推荐答案

对于GDI，您可以将 GetDeviceCaps 函数与 LOGPIXELSX 和 LOGPIXELSY 一起使用找到您的DPI，并使用这些值来缩放尺寸:

With GDI, you can use GetDeviceCaps function with LOGPIXELSX and LOGPIXELSY to find your DPI, and use these values to scale your sizes:

HDC hdc = GetDC(hwnd);
int ppix = GetDeviceCaps(hdc, LOGPIXELSX);
int ppiy = GetDeviceCaps(hdc, LOGPIXELSY);
ReleaseDC(hdc);

// for a control that is 1.5 inches wide and 0.5 inches high.

int ctrl_width = int(1.5 * ppix + 0.5);
int ctrl_height = int(0.5 * ppiy + 0.5);

// for a button that conforms to Microsoft's UI guidelines of 75x23 @ 96dpi.

int btn_width = (75 * ppix + 48) / 96;
int btn_height = (23 * ppiy + 48) / 96;

GDI +使这一过程变得更加简单:

GDI+ makes this considerably simpler:

Graphics g;
g.SetPageUnit(UnitInch);

// now you can specify draw coordinates in inches
// and it'll figure out DPI for you.

请注意，GDI +解决方案只会影响GDI +绘图调用，而不会影响GDI调用或控件坐标.

Do note that the GDI+ solution will only affect GDI+ draw calls—not GDI calls or coordinates of controls.

这篇关于真正需要DPI意识吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！