Mobile interface Devicepixelratio problem and mobile soft keyboard keycode

Now the mobile side of the particle size is getting smaller, so the sharpness is very high, such as Huawei P9 Devicepixelratio is 4,

This is how perverted, Devicepixelratio is the physical pixel/logical pixel = magnification devicepixelratio, so

If the magnification is 4, a pixel is magnified 4 times times on the device, so real 4 pixels is difficult to display on the device,

Can only be achieved using the means of scaling, which is like why the 1px frame is difficult to implement in the device, now the device is

Magnification is 2, so often on the internet to see the 0.5 css way, which is why you can often see some UI design diagram

There will be @3x\@2x and other graphic design, because compatible with 3, twice times the rate of equipment, mobile phone tablets are most easily found blurred.

TARGET-DENSITYDPI has been abandoned, so don't use it.

Before the introduction of VW, you can use it, then it can be less laborious development: Gulp automatically compiled into the CSS of the VW unit

Information:

Viewport cell phone logic pixel and physical pixel principle

CSS pixels, physical pixels, logical pixels, devices like silverhalide, PPI, Viewport

Mobile Soft keyboard keycode get only KeyUp and KeyDown to get, others are not, or have compatibility issues.
There is also a general input too fast or too much input to the text box, and the input of Chinese, etc. will appear 229, so this is also the problem,
So I don't think it's necessary to use it, because it doesn't want to use it as accurately as the PC side.
The appearance of the soft keyboard will change the height, so you can get the document height confirmation or resize event directly.
There are more than one input that will not constantly trigger a flex keyboard, only the first trigger after the other switchover trigger will not be triggered.
So six lattices can be implemented directly with 6 input.

Type types are again moving the end of the function relatively large.
For example, Type=number directly is the number nine Gongge, can not input +--number of characters,
Type=tel, just like a cell phone, can only enter the phone's format content.
Like numbers * #等

Mobile interface Devicepixelratio problem and mobile soft keyboard keycode