Introduction to WeChat Mini Program Page() function

This article mainly introduces relevant information about the detailed explanation of the Page() function of the WeChat applet. You will definitely encounter the Page() function during the development process. I hope it can help everyone. Friends in need can refer to it

WeChat Mini Program——Page():

When you encounter a function or something you don’t understand when developing a WeChat Mini Program, it’s best to It's better to check the official website and get the corresponding knowledge. Here, the editor will help you sort out the usage of the page() function.

object parameter description:

Sample code:

//index.js 
Page({ 
 data: { 
  text: "This is page data." 
 }, 
 onLoad: function(options) { 
  // Do some initialize when page load. 
 }, 
 onReady: function() { 
  // Do something when page ready. 
 }, 
 onShow: function() { 
  // Do something when page show. 
 }, 
 onHide: function() { 
  // Do something when page hide. 
 }, 
 onUnload: function() { 
  // Do something when page close. 
 }, 
 onPullDownRefresh: function() { 
  // Do something when pull down 
 }, 
 // Event handler. 
 viewTap: function() { 
  this.setData({ 
   text: 'Set some data for updating view.' 
  }) 
 } 
})

Initialization data

Initialization data will be used as page of the first rendering. The data will be transmitted from the logic layer to the rendering layer in the form of JSON, so the data must be in a format that can be converted into JSON: strings, numbers, Boolean values, objects, and arrays.
The rendering layer can bind data through WXML.

Sample code:

<view>{{text}}</view> 
<view>{{array[0].msg}}</view>

Page({ 
 data: { 
  text: 'init data', 
  array: [{msg: '1'}, {msg: '2'}] 
 } 
})

Life cycle function

onLoad: Page loading

A page will only be called once.

The parameters can be obtained from wx.navigateTo, wx.redirectTo and query in .

onShow: Page display

will be called every time the page is opened.

onReady: The initial rendering of the page is completed

A page will only be called once, which means that the page is ready and can interact with the view layer.

Please set interface settings such as wx.setNavigationBarTitle after onReady. For details, see Life Cycle

onHide: Page Hide

Called when navigateTo or the bottom tab is switched.

onUnload: Page unloading

Called when redirectTo or navigateBack.

Page related event processing function

onPullDownRefresh: Pull-down refresh

Listen to user pull-down refresh events.

You need to enable enablePullDownRefresh in the window option of config.

After processing the data refresh, wx.stopPullDownRefresh can stop the pull-down refresh of the current page.

Event handling function

In addition to initialization data and life cycle functions, Page can also define some special functions: event handling functions. In the rendering layer, event binding can be added to the component. When the trigger event is reached, the event processing function defined in Page will be executed.

Sample code:

click me

Page({ 
 viewTap: function() { 
  console.log('view tap') 
 } 
})

Page.prototype.setData()

The setData function is used to send data from the logic layer to the view layer and change the corresponding this.data value.

Note:

Directly modifying this.data is invalid and cannot change the status of the page. It will also cause data inconsistency.
The data set at a time cannot exceed 1024kB. Please try to avoid setting too much data at one time.

setData() parameter format

Accepts an object and represents the value corresponding to the key in this.data in the form of key and value. Change to value.
The key can be very flexible and given in the form of a data path, such as array[2].message, a.b.c.d, and does not need to be predefined in this.data.

Sample code:

<view>{{text}}</view> 
<button bindtap="changeText"> Change normal data </button> 
<view>{{array[0].text}}</view> 
<button bindtap="changeItemInArray"> Change Array data </button> 
<view>{{obj.text}}</view> 
<button bindtap="changeItemInObject"> Change Object data </button> 
<view>{{newField.text}}</view> 
<button bindtap="addNewField"> Add new data </button>

##

//index.js 
Page({ 
 data: { 
  text: 'init data', 
  array: [{text: 'init data'}], 
  object: { 
   text: 'init data' 
  } 
 }, 
 changeText: function() { 
  // this.data.text = 'changed data' // bad, it can not work 
  this.setData({ 
   text: 'changed data' 
  }) 
 }, 
 changeItemInArray: function() { 
  // you can use this way to modify a danamic data path 
  this.setData({ 
   'array[0].text':'changed data' 
  }) 
 }, 
 changeItemInObject: function(){ 
  this.setData({ 
   'object.text': 'changed data' 
  }); 
 }, 
 addNewField: function() { 
  this.setData({ 
   'newField.text': 'new data' 
  }) 
 } 
})

Life cycle

Page routing

Routing method

Related recommendations:

##WeChat Mini Program Introduction to program-getUserInfo callback

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