harmony 鸿蒙<button> Development

2022-08-09
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<button> Development

The <button> component can be used to set a capsule, circle, text, arc, or download button. For details, see button.

Creating a <button> Component

Create a <button> component in the .hml file under pages/index.

<!-- xxx.hml -->
<div class="container">       
  <button  type="capsule" value="Capsule button"></button>
</div>

/* xxx.css */
.container {
  width: 100%;
  height: 100%;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background-color: #F1F3F5;
}

en-us_image_0000001267887821

Setting the Button Type

Set the type attribute of the <button> component to circle, text, or any other supported value.

<!-- xxx.hml -->
<div class="container">    
  <button class="circle" type="circle" >+</button>
  <button class="text" type="text"> button</button>
</div>

/* xxx.css */
.container {  
  width: 100%;
  height: 100%;
  background-color: #F1F3F5;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.circle {
  font-size: 120px;
  background-color: blue;
  radius: 72px;
}
.text {
  margin-top: 30px;
  text-color: white;
  font-size: 30px;
  font-style: normal;
  background-color: blue;
  width: 50%;
  height: 100px;
}

en-us_image_0000001222967744

NOTE

If the icon used by the <button> component is from the cloud, you must declare the ohos.permission.INTERNET permission in the config.json file under the resources folder.

Sample code for declaring the ohos.permission.INTERNET permission in the config.json file under the resources folder:

<!-- config.json -->
"module": {
  "reqPermissions": [{
    "name": "ohos.permission.INTERNET"
  }],
}

Showing the Download Progress

Add the progress method to the <button> component to display the download progress in real time.

<!-- xxx.hml -->
<div class="container">
  <button class="button download" type="download" id="download-btn" onclick="setProgress">{{downloadText}}</button>
</div>

/* xxx.css */
.container { 
  width: 100%;
  height: 100%;
  background-color: #F1F3F5;  
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.download {    
  width: 280px;
  text-color: white;
  background-color: #007dff;
}

// xxx.js
import promptAction from '@ohos.promptAction';
export default {
  data: {
    percent: 0,
    downloadText: "Download",
    isPaused: true,
    intervalId : null,
  },
  start(){
    this.intervalId = setInterval(()=>{
      if(this.percent <100){
        this.percent += 1;
        this.downloadText = this.percent+ "%";
       } else{
         promptAction.showToast({
            message: "Download succeeded."
         })
         this.paused()
         this.downloadText = "Download";
         this.percent = 0;
         this.isPaused = true;
       }
    },100)
  },
  paused(){
    clearInterval(this.intervalId);
    this.intervalId = null;
  },
 setProgress(e) {
    if(this.isPaused){
      promptAction.showToast({
        message: "Started Downloading"
      })
      this.start();
      this.isPaused = false;
    }else{
      promptAction.showToast({
        message: "Paused."
      })
      this.paused();
      this.isPaused = true;
    }
  }
}

en-us_image_0000001223287652

NOTE

The setProgress method supports only buttons of the download type.

Example Scenario

Switch between the button types for different types of text.

<!-- xxx.hml -->
<div class="container">
  <div class="input-item">
    <input class="input-text" id="change" type="{{mytype}}"  placeholder="{{myholder}}" 
      style="background-color:{{mystyle1}};
      placeholder-color:{{mystyle2}};flex-grow:{{myflex}};"name="{{myname}}" value="{{myvalue}}"></input>
  </div>
  <div class="input-item">
    <div class="doc-row">
      <input type="button" class="select-button color-3" value="text" onclick="changetype3"></input>
      <input type="button" class="select-button color-3" value="data" onclick="changetype4"></input>
    </div>
  </div>
</div>

/* xxx.css */
.container {
  flex-direction: column;
  align-items: center;
  background-color: #F1F3F5;
}
.input-item {
  margin-bottom: 80px;
  flex-direction: column;
}
.doc-row {
  justify-content: center;
  margin-left: 30px;
  margin-right: 30px;
  justify-content: space-around;
}
.input-text {
  height: 80px;
  line-height: 80px;
  padding-left: 30px;
  padding-right: 30px;
  margin-left: 30px;
  margin-right: 30px;
  margin-top:100px;
  border: 3px solid;
  border-color: #999999;
  font-size: 30px;
  background-color: #ffffff;
  font-weight: 400;
}
.select-button {
  width: 35%;
  text-align: center;
  height: 70px;
  padding-top: 10px;
  padding-bottom: 10px;
  margin-top: 30px;
  font-size: 30px;
  color: #ffffff;
}
.color-3 {
  background-color: #0598db;;
}

// xxx.js
export default {
  data: {
    myflex: '',
    myholder: 'Enter text.',
    myname: '',
    mystyle1: "#ffffff",
    mystyle2: "#ff0000",
    mytype: 'text',
    myvalue: '',
  },
  onInit() {
  },
  changetype3() {
    this.myflex = '';
    this.myholder = 'Enter text.';
    this.myname = '';
    this.mystyle1 = "#ffffff";
    this.mystyle2 = "#FF0000";
    this.mytype = 'text';
    this.myvalue = '';
  },
  changetype4() {
    this.myflex = '';
    this.myholder = 'Enter a date.';
    this.myname = '';
    this.mystyle1 = "#ffffff";
    this.mystyle2 = "#FF0000";
    this.mytype = 'date';
    this.myvalue = '';
  },
}

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