Cette fois, je vais vous donner une explication détaillée des étapes pour réaliser un déplacement en forme d'arc barre de progression , et quelles sont les précautions pour implémenter une barre de progression de déplacement en forme d'arc. Ce qui suit est un cas pratique, jetons un coup d'œil.
D'abord le rendu
Car la demande nécessite l'implémentation non native de ce rendu,
Difficulté 1 : Dessiner en utilisant svg
Difficulté 2 : Traitement des événements de clic
Difficulté 3 : Encapsulation
Puisque le dessin doit utiliser SVG
Ici, Baidu suit le tutoriel SVG et API
Afficher le bloc de code
render() { return ( <View pointerEvents={'box-only'} //事件处理 {...this._panResponder.panHandlers}> //实际圆环 {this._renderCircleSvg()} // 计算中心距离 <View style={{ position: 'relative', top: -this.props.height / 2 - this.props.r, left: this.props.width / 2 - this.props.r, flex: 1, }}> // 暴露给外部渲染圆环中心的接口 {this.props.renderCenterView(this.state.temp)} </View> </View> ); _renderCircleSvg() { //中心点 const cx = this.props.width / 2; const cy = this.props.height / 2; //计算是否有偏差角 对应图就是下面缺了一块的 const prad = this.props.angle / 2 * (Math.PI / 180); //三角计算起点 const startX = -(Math.sin(prad) * this.props.r) + cx; const startY = cy + Math.cos(prad) * this.props.r; //终点 const endX = Math.sin(prad) * this.props.r + cx; const endY = cy + Math.cos(prad) * this.props.r; // 计算进度点 const progress = parseInt( this._circlerate() * (360 - this.props.angle) / 100, 10 ); // 根据象限做处理 苦苦苦 高中数学全忘了,参考辅助线 const t = progress + this.props.angle / 2; const progressX = cx - Math.sin(t * (Math.PI / 180)) * this.props.r; const progressY = cy + Math.cos(t * (Math.PI / 180)) * this.props.r; // SVG的描述 这里百度下就知道什么意思 const descriptions = [ 'M', startX, startY, 'A', this.props.r, this.props.r, 0, 1, 1, endX, endY, ].join(' '); const progressdescription = [ 'M', startX, startY, 'A', this.props.r, this.props.r, 0, //根据角度是否是0,1 看下效果就知道了 t >= 180 + this.props.angle / 2 ? 1 : 0, 1, progressX, progressY, ].join(' '); return ( <Svg height={this.props.height} width={this.props.width} style={styles.svg}> <Path d={descriptions} fill="none" stroke={this.props.outArcColor} strokeWidth={this.props.strokeWidth} /> <Path d={progressdescription} fill="none" stroke={this.props.progressvalue} strokeWidth={this.props.strokeWidth} /> <Circle cx={progressX} cy={progressY} r={this.props.tabR} stroke={this.props.tabStrokeColor} strokeWidth={this.props.tabStrokeWidth} fill={this.props.tabColor} /> </Svg> ); } }
Bloc de code de traitement des événements
// 参考react native 官网对手势的讲解 iniPanResponder() { this.parseToDeg = this.parseToDeg.bind(this); this._panResponder = PanResponder.create({ // 要求成为响应者: onStartShouldSetPanResponder: () => true, onStartShouldSetPanResponderCapture: () => true, onMoveShouldSetPanResponder: () => true, onMoveShouldSetPanResponderCapture: () => true, onPanResponderGrant: evt => { // 开始手势操作。给用户一些视觉反馈,让他们知道发生了什么事情! if (this.props.enTouch) { this.lastTemper = this.state.temp; const x = evt.nativeEvent.locationX; const y = evt.nativeEvent.locationY; this.parseToDeg(x, y); } }, onPanResponderMove: (evt, gestureState) => { if (this.props.enTouch) { let x = evt.nativeEvent.locationX; let y = evt.nativeEvent.locationY; if (Platform.OS === 'android') { x = evt.nativeEvent.locationX + gestureState.dx; y = evt.nativeEvent.locationY + gestureState.dy; } this.parseToDeg(x, y); } }, onPanResponderTerminationRequest: () => true, onPanResponderRelease: () => { if (this.props.enTouch) this.props.complete(this.state.temp); }, // 另一个组件已经成为了新的响应者,所以当前手势将被取消。 onPanResponderTerminate: () => {}, // 返回一个布尔值,决定当前组件是否应该阻止原生组件成为JS响应者 // 默认返回true。目前暂时只支持android。 onShouldBlockNativeResponder: () => true, }); } //画象限看看就知道了 就是和中线点计算角度 parseToDeg(x, y) { const cx = this.props.width / 2; const cy = this.props.height / 2; let deg; let temp; if (x >= cx && y <= cy) { deg = Math.atan((cy - y) / (x - cx)) * 180 / Math.PI; temp = (270 - deg - this.props.angle / 2) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } else if (x >= cx && y >= cy) { deg = Math.atan((cy - y) / (cx - x)) * 180 / Math.PI; temp = (270 + deg - this.props.angle / 2) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } else if (x <= cx && y <= cy) { deg = Math.atan((x - cx) / (y - cy)) * 180 / Math.PI; temp = (180 - this.props.angle / 2 - deg) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } else if (x <= cx && y >= cy) { deg = Math.atan((cx - x) / (y - cy)) * 180 / Math.PI; if (deg < this.props.angle / 2) { deg = this.props.angle / 2; } temp = (deg - this.props.angle / 2) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } if (temp <= this.props.min) { temp = this.props.min; } if (temp >= this.props.max) { temp = this.props.max; } //因为提供步长,所欲需要做接近步长的数 temp = this.getTemps(temp); this.setState({ temp, }); this.props.valueChange(this.state.temp); } getTemps(tmps) { const k = parseInt((tmps - this.props.min) / this.props.step, 10); const k1 = this.props.min + this.props.step * k; const k2 = this.props.min + this.props.step * (k + 1); if (Math.abs(k1 - tmps) > Math.abs(k2 - tmps)) return k2; return k1; }
Blocage de code complet
import React, { Component } from 'react'; import { View, StyleSheet, PanResponder, Platform, Text } from 'react-native'; import Svg, { Circle, Path } from 'react-native-svg'; export default class CircleView extends Component { static propTypes = { height: React.PropTypes.number, width: React.PropTypes.number, r: React.PropTypes.number, angle: React.PropTypes.number, outArcColor: React.PropTypes.object, progressvalue: React.PropTypes.object, tabColor: React.PropTypes.object, tabStrokeColor: React.PropTypes.object, strokeWidth: React.PropTypes.number, value: React.PropTypes.number, min: React.PropTypes.number, max: React.PropTypes.number, tabR: React.PropTypes.number, step: React.PropTypes.number, tabStrokeWidth: React.PropTypes.number, valueChange: React.PropTypes.func, renderCenterView: React.PropTypes.func, complete: React.PropTypes.func, enTouch: React.PropTypes.boolean, }; static defaultProps = { width: 300, height: 300, r: 100, angle: 60, outArcColor: 'white', strokeWidth: 10, value: 20, min: 10, max: 70, progressvalue: '#ED8D1B', tabR: 15, tabColor: '#EFE526', tabStrokeWidth: 5, tabStrokeColor: '#86BA38', valueChange: () => {}, complete: () => {}, renderCenterView: () => {}, step: 1, enTouch: true, }; constructor(props) { super(props); this.state = { temp: this.props.value, }; this.iniPanResponder(); } iniPanResponder() { this.parseToDeg = this.parseToDeg.bind(this); this._panResponder = PanResponder.create({ // 要求成为响应者: onStartShouldSetPanResponder: () => true, onStartShouldSetPanResponderCapture: () => true, onMoveShouldSetPanResponder: () => true, onMoveShouldSetPanResponderCapture: () => true, onPanResponderGrant: evt => { // 开始手势操作。给用户一些视觉反馈,让他们知道发生了什么事情! if (this.props.enTouch) { this.lastTemper = this.state.temp; const x = evt.nativeEvent.locationX; const y = evt.nativeEvent.locationY; this.parseToDeg(x, y); } }, onPanResponderMove: (evt, gestureState) => { if (this.props.enTouch) { let x = evt.nativeEvent.locationX; let y = evt.nativeEvent.locationY; if (Platform.OS === 'android') { x = evt.nativeEvent.locationX + gestureState.dx; y = evt.nativeEvent.locationY + gestureState.dy; } this.parseToDeg(x, y); } }, onPanResponderTerminationRequest: () => true, onPanResponderRelease: () => { if (this.props.enTouch) this.props.complete(this.state.temp); }, // 另一个组件已经成为了新的响应者,所以当前手势将被取消。 onPanResponderTerminate: () => {}, // 返回一个布尔值,决定当前组件是否应该阻止原生组件成为JS响应者 // 默认返回true。目前暂时只支持android。 onShouldBlockNativeResponder: () => true, }); } componentWillReceiveProps(nextProps) { if (nextProps.value != this.state.temp) { this.state = { temp: nextProps.value, }; } } parseToDeg(x, y) { const cx = this.props.width / 2; const cy = this.props.height / 2; let deg; let temp; if (x >= cx && y <= cy) { deg = Math.atan((cy - y) / (x - cx)) * 180 / Math.PI; temp = (270 - deg - this.props.angle / 2) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } else if (x >= cx && y >= cy) { deg = Math.atan((cy - y) / (cx - x)) * 180 / Math.PI; temp = (270 + deg - this.props.angle / 2) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } else if (x <= cx && y <= cy) { deg = Math.atan((x - cx) / (y - cy)) * 180 / Math.PI; temp = (180 - this.props.angle / 2 - deg) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } else if (x <= cx && y >= cy) { deg = Math.atan((cx - x) / (y - cy)) * 180 / Math.PI; if (deg < this.props.angle / 2) { deg = this.props.angle / 2; } temp = (deg - this.props.angle / 2) / (360 - this.props.angle) * (this.props.max - this.props.min) + this.props.min; } if (temp <= this.props.min) { temp = this.props.min; } if (temp >= this.props.max) { temp = this.props.max; } temp = this.getTemps(temp); this.setState({ temp, }); this.props.valueChange(this.state.temp); } getTemps(tmps) { const k = parseInt((tmps - this.props.min) / this.props.step, 10); const k1 = this.props.min + this.props.step * k; const k2 = this.props.min + this.props.step * (k + 1); if (Math.abs(k1 - tmps) > Math.abs(k2 - tmps)) return k2; return k1; } render() { return ( <View pointerEvents={'box-only'} {...this._panResponder.panHandlers}> {this._renderCircleSvg()} <View style={{ position: 'relative', top: -this.props.height / 2 - this.props.r, left: this.props.width / 2 - this.props.r, flex: 1, }}> {this.props.renderCenterView(this.state.temp)} </View> </View> ); } _circlerate() { let rate = parseInt( (this.state.temp - this.props.min) * 100 / (this.props.max - this.props.min), 10 ); if (rate < 0) { rate = 0; } else if (rate > 100) { rate = 100; } return rate; } _renderCircleSvg() { const cx = this.props.width / 2; const cy = this.props.height / 2; const prad = this.props.angle / 2 * (Math.PI / 180); const startX = -(Math.sin(prad) * this.props.r) + cx; const startY = cy + Math.cos(prad) * this.props.r; // // 最外层的圆弧配置 const endX = Math.sin(prad) * this.props.r + cx; const endY = cy + Math.cos(prad) * this.props.r; // 计算进度点 const progress = parseInt( this._circlerate() * (360 - this.props.angle) / 100, 10 ); // 根据象限做处理 苦苦苦 高中数学全忘了,参考辅助线 const t = progress + this.props.angle / 2; const progressX = cx - Math.sin(t * (Math.PI / 180)) * this.props.r; const progressY = cy + Math.cos(t * (Math.PI / 180)) * this.props.r; const descriptions = [ 'M', startX, startY, 'A', this.props.r, this.props.r, 0, 1, 1, endX, endY, ].join(' '); const progressdescription = [ 'M', startX, startY, 'A', this.props.r, this.props.r, 0, t >= 180 + this.props.angle / 2 ? 1 : 0, 1, progressX, progressY, ].join(' '); return ( <Svg height={this.props.height} width={this.props.width} style={styles.svg}> <Path d={descriptions} fill="none" stroke={this.props.outArcColor} strokeWidth={this.props.strokeWidth} /> <Path d={progressdescription} fill="none" stroke={this.props.progressvalue} strokeWidth={this.props.strokeWidth} /> <Circle cx={progressX} cy={progressY} r={this.props.tabR} stroke={this.props.tabStrokeColor} strokeWidth={this.props.tabStrokeWidth} fill={this.props.tabColor} /> </Svg> ); } } const styles = StyleSheet.create({ svg: {}, });
Appel externe
<View style={styles.container}> <CircleProgress width={width} height={height} r={r} angle={60} min={5} max={35} step={0.5} value={22} complete={temp => { }} valueChange={temp => {}} renderCenterView={temp => ( <View style={{ flex: 1 }}> </View> )} enTouch={true} /> </View>
Je pense que vous maîtrisez la méthode après avoir lu le cas dans cet article Pour des choses plus passionnantes. , veuillez faire attention à php Chinois Autres articles connexes en ligne !
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