【HarmonyOS Next之旅】基于ArkTS开发(三) -＞ 兼容JS的类Web开发(七) -＞ JS动画(二)

目录

1 -> 动画动效

1.1 -> 创建动画对象

1.2 -> 添加动画事件和调用接口

2 -> 动画帧

2.1 -> 请求动画帧

2.2 -> 取消动画帧

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1 -> 动画动效

通过设置插值器来实现动画效果。

说明

从API Version 6 开始支持。

1.1 -> 创建动画对象

通过createAnimator创建一个动画对象，通过设置参数options来设置动画的属性。

<!-- test.hml -->
<div class="container"><div style="width: 300px;height: 300px;margin-top: 100px;background: linear-gradient(pink, purple);transform: translate({{translateVal}});"></div><div class="row"><button type="capsule" value="play" onclick="playAnimation"></button></div>
</div>

/* test.css */
.container {width:100%;height:100%;flex-direction: column;align-items: center;justify-content: center;
}
button{width: 200px;
}
.row{width: 65%;height: 100px;align-items: center;justify-content: space-between;margin-top: 50px;margin-left: 260px;
}

/* test.js */
import animator from '@ohos.animator';
export default {data: {translateVal: 0,animation: null},onInit() {},onShow(){var options = {duration: 3000,easing:"friction",delay:"1000",fill: 'forwards',direction:'alternate',iterations: 2,begin: 0,end: 180};//设置参数this.animation = animator.createAnimator(options)//创建动画},playAnimation() {var _this = this;this.animation.onframe = function(value) {_this.translateVal= value};this.animation.play();}
}

说明

• 使用createAnimator创建动画对象时必须传入options参数。

• begin插值起点，不设置时默认为0。

• end插值终点，不设置时默认为1。

1.2 -> 添加动画事件和调用接口

animator支持事件和接口，可以通过添加frame、cancel、repeat、finish事件和调用update、play、pause、cancel、reverse、finish接口自定义动画效果。animator支持的事件和接口具体见动画中的createAnimator。

<!-- test.hml -->
<div style="flex-direction: column;align-items: center;width: 100%;height: 100%;"><div style="width:200px;height: 200px;margin-top: 100px;background: linear-gradient(#b30d29, #dcac1b);transform: scale({{scaleVal}});"></div><div style="width: {{DivWidth}};height: {{DivHeight}};margin-top: 200px;background: linear-gradient(pink, purple);margin-top: 200px;transform:translateY({{translateVal}});"></div><div class="row"><button type="capsule" value="play" onclick="playAnimation"></button><button type="capsule" value="update" onclick="updateAnimation"></button></div><div class="row1"><button type="capsule" value="pause" onclick="pauseAnimation"></button><button type="capsule" value="finish" onclick="finishAnimation"></button></div><div class="row2"><button type="capsule" value="cancel" onclick="cancelAnimation"></button><button type="capsule" value="reverse" onclick="reverseAnimation"></button></div>
</div>

/* test.css */
button{width: 200px;
}
.row{width: 65%;height: 100px;align-items: center;justify-content: space-between;margin-top: 150px;position: fixed;top: 52%;left: 120px;
}
.row1{width: 65%;height: 100px;align-items: center;justify-content: space-between;margin-top: 120px;position: fixed;top: 65%;left: 120px;
}
.row2{width: 65%;height: 100px;align-items: center;justify-content: space-between;margin-top: 100px;position: fixed;top: 75%;left: 120px;
}

/* test.js */
import animator from '@ohos.animator';
import prompt from '@system.prompt';
export default {data: {scaleVal:1,DivWidth:200,DivHeight:200,translateVal:0,animation: null},onInit() {var options = {duration: 3000,fill: 'forwards',begin: 200,end: 270};this.animation = animator.createAnimator(options);},onShow() {var _this= this;//添加动画重放事件this.animation.onrepeat = function() {prompt.showToast({message: 'repeat'});var repeatoptions = {duration: 2000,iterations: 1,direction: 'alternate',begin: 180,end: 240};_this.animation.update(repeatoptions);_this.animation.play();};},playAnimation() {var _this= this;//添加动画逐帧插值回调事件this.animation.onframe = function(value) {_this. scaleVal= value/150,_this.DivWidth = value,_this.DivHeight = value,_this.translateVal = value-180};this.animation.play();},updateAnimation() {var newoptions = {duration: 5000,iterations: 2,begin: 120,end: 180};this.animation.update(newoptions);this.animation.play();//调用动画播放接口},pauseAnimation() {this.animation.pause();//调用动画暂停接口},finishAnimation() {var _this= this;//添加动画完成事件this.animation.onfinish = function() {prompt.showToast({message: 'finish'})};this.animation.finish(); //调用动画完成接口},cancelAnimation() {this.animation.cancel(); //调用动画取消接口},reverseAnimation() {this.animation.reverse(); //调用动画倒放接口}
}

说明

在调用update接口的过程中可以使用这个接口更新动画参数，入参与createAnimator一致。

2 -> 动画帧

2.1 -> 请求动画帧

请求动画帧时通过requestAnimationFrame函数逐帧回调，在调用该函数时传入一个回调函数。

runframe在调用requestAnimationFrame时传入带有timestamp参数的回调函数step，将step中的timestamp赋予起始的startTime。当timestamp与startTime的差值小于规定的时间时将再次调用requestAnimationFrame，最终动画将会停止。

<!-- test.hml -->
<div class="container"><tabs onchange="changecontent"><tab-content><div class="container"><stack style="width: 300px;height: 300px;margin-top: 100px;margin-bottom: 100px;"><canvas id="mycanvas" style="width: 100%;height: 100%;background-color: coral;"></canvas><div style="width: 50px;height: 50px;border-radius: 25px;background-color: indigo;position: absolute;left: {{left}};top: {{top}};"></div></stack><button type="capsule" value="play" onclick="runframe"></button></div></tab-content></tabs>
</div>

/* test.css */
.container {flex-direction: column;justify-content: center;align-items: center;width: 100%;height: 100%;
}
button{width: 300px;
}

/* test.js */
export default {data: {timer: null,left: 0,top: 0,flag: true,animation: null,startTime: 0,},onShow() {var test = this.$element("mycanvas");var ctx = test.getContext("2d");ctx.beginPath();ctx.moveTo(0, 0);ctx.lineTo(300, 300);ctx.lineWidth = 5;ctx.strokeStyle = "red";ctx.stroke();},runframe() {this.left = 0;this.top = 0;this.flag = true;this.animation = requestAnimationFrame(this.step);},step(timestamp) {if (this.flag) {this.left += 5;this.top += 5;if (this.startTime == 0) {this.startTime = timestamp;}var elapsed = timestamp - this.startTime;if (elapsed < 500) {console.log('callback step timestamp: ' + timestamp);this.animation = requestAnimationFrame(this.step);}} else {this.left -= 5;this.top -= 5;this.animation = requestAnimationFrame(this.step);}if (this.left == 250 || this.left == 0) {this.flag = !this.flag}},onDestroy() {cancelAnimationFrame(this.animation);}
}

说明

requestAnimationFrame函数在调用回调函数时在第一个参数位置传入timestamp时间戳，表示requestAnimationFrame开始去执行回调函数的时刻。

2.2 -> 取消动画帧

通过cancelAnimationFrame函数取消逐帧回调，在调用cancelAnimationFrame函数时取消requestAnimationFrame函数的请求。

<!-- test.hml -->
<div class="container"><tabs onchange="changecontent"><tab-content><div class="container"><stack style="width: 300px;height: 300px;margin-top: 100px;margin-bottom: 100px;"><canvas id="mycanvas" style="width: 100%;height: 100%;background-color: coral;"></canvas><div style="width: 50px;height: 50px;border-radius: 25px;background-color: indigo;position: absolute;left: {{left}};top: {{top}};"></div></stack><button type="capsule" value="play" onclick="runframe"></button></div></tab-content></tabs>
</div>

/* test.css */
.container {flex-direction: column;justify-content: center;align-items: center;width: 100%;height: 100%;
}
button{width: 300px;
}

/* test.js */
export default {data: {timer: null,left: 0,top: 0,flag: true,animation: null},onShow() {var test = this.$element("mycanvas");var ctx = test.getContext("2d");ctx.beginPath();ctx.moveTo(0, 0);ctx.lineTo(300, 300);ctx.lineWidth = 5;ctx.strokeStyle = "red";ctx.stroke();},runframe() {this.left = 0;this.top = 0;this.flag = true;this.animation = requestAnimationFrame(this.step);},step(timestamp) {if (this.flag) {this.left += 5;this.top += 5;this.animation = requestAnimationFrame(this.step);} else {this.left -= 5;this.top -= 5;this.animation = requestAnimationFrame(this.step);}if (this.left == 250 || this.left == 0) {this.flag = !this.flag}},onDestroy() {cancelAnimationFrame(this.animation);}
}

说明

在调用该函数时需传入一个具有标识id的参数。

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感谢各位大佬支持！！！

互三啦！！！