150 lines
3.4 KiB
Vue
150 lines
3.4 KiB
Vue
<template>
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<view>
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<!-- 只创建一个Canvas用于复用 -->
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<canvas
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type="2d"
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canvas-id="reusableCanvas"
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:width="currentCanvasWidth"
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:height="currentCanvasHeight"
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class="offscreen-canvas"
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></canvas>
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</view>
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</template>
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<script>
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export default {
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name: "TextToHex",
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props: {
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txts: {
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type: Array,
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default: () => [],
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validator: (value) => value.every(item => typeof item === 'string')
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},
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fontSize: {
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type: Number,
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default: 16,
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validator: (value) => value > 0 && value <= 100
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},
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bgColor:{
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type:String,
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default:"#000000"
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},
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color:{
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type:String,
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default:"#FFFFFF"
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}
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},
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data() {
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return {
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// 当前Canvas的宽高（动态调整）
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currentCanvasWidth: 0,
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currentCanvasHeight: 0,
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// Canvas上下文（复用）
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ctx: null
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};
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},
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computed: {
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validTxts() {
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return this.txts.filter(line => line.trim() !== '');
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}
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},
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mounted() {
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// 初始化Canvas上下文（只创建一次）
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this.ctx = uni.createCanvasContext('reusableCanvas', this);
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},
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methods: {
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/**
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* 估算单行文本所需的Canvas宽度
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*/
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calcLineWidth(textLine) {
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return textLine.length * this.fontSize;
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},
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/**
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* 清除Canvas内容
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*/
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clearCanvas() {
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this.ctx.setFillStyle(this.bgColor);
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this.ctx.fillRect(0, 0, this.currentCanvasWidth, this.currentCanvasHeight);
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},
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/**
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* 复用单个Canvas处理所有文本行
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*/
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async drawAndGetPixels() {
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if (this.validTxts.length === 0) {
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return [];
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}
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const result = [];
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const ctx = this.ctx;
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// 循环处理每行文本
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for (let i = 0; i < this.validTxts.length; i++) {
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const textLine = this.validTxts[i];
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// 1. 动态调整Canvas尺寸
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this.currentCanvasWidth = this.calcLineWidth(textLine);
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this.currentCanvasHeight = this.fontSize;
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// 2. 清空Canvas（绘制背景）
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this.clearCanvas();
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// 3. 设置文字样式
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ctx.setFillStyle(this.color);
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ctx.setTextBaseline('middle');
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ctx.setFontSize(this.fontSize);
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ctx.font = `${this.fontSize}px SimHei, Microsoft YaHei, Arial, sans-serif`;
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// 4. 绘制当前行文本
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let currentX = 0;
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const currentY = this.fontSize / 2;
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for (let j = 0; j < textLine.length; j++) {
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const char = textLine[j];
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ctx.fillText(char, currentX, currentY);
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// 按实际字符宽度计算间距
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const charWidth = ctx.measureText(char).width;
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currentX += charWidth ;
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}
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// 5. 异步绘制并获取像素数据（串行处理避免冲突）
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await new Promise((resolve, reject) => {
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ctx.draw(false, () => {
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uni.canvasGetImageData({
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canvasId: 'reusableCanvas',
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x: 0,
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y: 0,
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width: this.currentCanvasWidth,
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height: this.currentCanvasHeight,
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success: res => {
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result.push({
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line: textLine,
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pixelData: res.data,
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width: this.currentCanvasWidth,
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height: this.currentCanvasHeight
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});
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resolve();
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},
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fail: err => {
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// console.error(`处理第${i+1}行失败:`, err);
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reject(err);
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}
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});
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});
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});
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}
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return result;
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}
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}
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};
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</script>
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<style >
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.offscreen-canvas {
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position: fixed;
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left: -9999px;
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top: -9999px;
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visibility: hidden;
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}
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</style>
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