What should I do if the dynamic upx in uniapp cannot take effect?

Uniapp is an open source front-end framework based on Vue.js. It provides a set of component-based development models based on Vue.js, which allows developers to more efficiently develop unified web, small programs, and apps. I believe that many developers will encounter various problems when using Uniapp to develop projects. This article will talk about the problem that dynamic upx cannot take effect in Uniapp.

What is upx?

First of all, let’s introduce what upx is. upx is a special CSS unit in Uniapp. It can automatically convert the px pixel value in the design draft into the physical pixel value under different devices to achieve screen adaptation.

As mobile phone screens continue to be updated, the screen pixels are getting higher and higher, and using px pixel values ​​to set styles will cause problems. For example, UI elements will become smaller on high-resolution devices. Upx is a solution that automatically converts pixel values ​​according to different screen resolutions to ensure that the UI displays consistently on all devices.

Why does dynamic upx fail to take effect?

When using Uniapp to develop projects, we often encounter the use of "dynamic styles" (dynamic binding styles), such as changing the color of buttons after clicking, etc. Different from static styles, using dynamic upx: <view :style="{ width: xxx 'upx' }" /> may not take effect in some cases. question.

Cause Analysis

In Uniapp, when using static upx to define a style, it will automatically convert upx to rpx pixel value. However, when using dynamic upx to define styles, Uniapp does not actively convert upx to rpx, but directly passes upx into the browser's rendering engine for calculation, which may lead to errors in the generated style.

Solution

There are two solutions to this problem:

1. Use rpx instead of upx

When using dynamic styles, we can Use rpx directly instead of upx, for example: <view :style="{ width: xxx 'rpx' }" />. At this time, Uniapp will automatically convert rpx into physical pixel values ​​on each device to ensure UI consistency.

2. Use the uni.upx2px() function to convert

If you must use upx, Uniapp provides the uni.upx2px() function to convert upx to rpx pixel value, the specific usage method is as follows:

<view :style="{ width: uni.upx2px(xxx) + &#39;rpx&#39; }" />

Using this method can ensure that upx can take effect normally.

Conclusion

This article briefly introduces the upx unit in Uniapp, as well as the problems you may encounter when using dynamic upx, and also provides two solutions. Although this problem may not be encountered by every developer, it is still very helpful to have this knowledge. I hope this article can be helpful to developers developing using Uniapp.

The above is the detailed content of What should I do if the dynamic upx in uniapp cannot take effect?. For more information, please follow other related articles on the PHP Chinese website!