[wechat applet] Chapter (5): basic API interface of wechat applet

Bowen author wangzirui32
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hello, Hello everyone , I am a wangzirui32, Today, let's learn the basics of wechat applet API Interface , Start learning ！

1. wx.request

function ： Request data from the server , Only initiation is supported HTTPS Network request .
Parameters ：

Example ：

   wx.request({
    
      url: 'https://114.51.4.191',
      data: {
    
        "a": "abc"
      },
    })

2. wx.downloadFile

function ： Download files on the network .
attribute ：

Callback function parameters after successful request ：

Example ：

    wx.downloadFile({
    
      url: 'https://11.45.14.19/files/19810',  //  Example resource address 
      success (res) {
    
        if (res.statusCode === 200) {
    
          alert("OK");
        };
    }})

3.wx.uploadFile()

function ： Upload the file to the designated url.
attribute

Call successfully callback parameters ：

Example ：

wx.uploadFile({
    
      url: 'https://11.45.14.19/upload',
      filePath: "example_filepath",
      name: 'file',
      formData: {
    
        'date': '2022-7-5'
      },
      success (res){
    
        var data = res.data;
      }
    })

4. wx.switchTab

function ： Jump to TabBar page .
attribute ：

Example ：

    wx.switchTab({
    
      url: '/example_1'
    })

5. wx.reLaunch

function ： Close all pages , Open to a page in the app .
attribute ：

Example ：

    wx.reLaunch({
    
      url: '/example_2'
    })

6. wx.redirectTo

function ： Jump to a page .
attribute ：

Example ：

    wx.redirectTo({
    
      url: '/example_3'
    })

7. wx.navigateTo

function ： Keep the current page , Jump to a page in the app .
attribute ：

Example ：

    wx.navigateTo({
    
      url: '/example_4'
    })

8. wx.navigateBack

function ： Close current page , Go back to the previous page .
attribute ：

Example ：

    wx.navigateBack({
    
      url: '/example_5'
    })

9. EventChannel

9.1 EventChannel.emit

function ： Trigger an event .
structure ：

EventChannel.emit( Event name )

9.2 EventChannel.off

function ： Cancel listening for an event .
structure ：

EventChannel.off( Event name ,  Callback function )

9.3 EventChannel.on

function ： Keep listening for an event .
structure ：

EventChannel.on( Event name ,  Callback function )

9.4 EventChannel.once

function ： Listen to an event once , Failure after triggering .
structure ：

EventChannel.once( Event name ,  Callback function )

10. wx.canIUse

function ： Judge the... Of the applet API, Callback , Parameters , Is the component available in the current version .
Return value ： Boolean value （True perhaps False）.
structure ：

wx.canIUse(schema)
// schema  Parameter format （ Yes 2 Kind of ）
// 1. ${API}.${method}.${param}.${option}
// 2. ${component}.${attribute}.${option}

Okay , That's all for today's lesson , I am a wangzirui32, You can collect and pay attention to what you like , See you next time ！