7305要13*13字体

components/TextToHex/textToDotMatrixFor7305.vue

@@ -35,7 +35,9 @@
 				currentCanvasWidth: 0,
 				currentCanvasHeight: 0,
 				// Canvas上下文（复用）
-				ctx: null
+				ctx: null,
+				// 标记画布是否已预热（解决首次发送像素不完整问题）
+				canvasWarmed: false
 			};
 		},
 		computed: {
@@ -63,10 +65,63 @@
 				this.ctx.fillRect(0, 0, this.currentCanvasWidth, this.currentCanvasHeight);
 			},
 
+			/**
+			 * 预热画布，防止 APP 首次调用时获取到的像素数据不完整
+			 */
+			async warmupCanvas() {
+				if (this.canvasWarmed) {
+					return;
+				}
+
+				try {
+					// 先用一个最小画布绘制测试字形，触发字体和 canvas 初始化
+					this.currentCanvasWidth = 16;
+					this.currentCanvasHeight = 16;
+					this.clearCanvas();
+					this.ctx.setFillStyle(this.color);
+					this.ctx.setFontSize(this.fontSize);
+					this.ctx.font = `${this.fontSize}px "PingFangBold", "PingFang SC", Arial, sans-serif`;
+					this.ctx.setTextBaseline('middle');
+					this.ctx.fillText('测', 0, 8);
+
+					await new Promise((resolve) => {
+						this.ctx.draw(false, () => {
+							// 读取一次数据，确保 canvasGetImageData 就绪
+							setTimeout(() => {
+								uni.canvasGetImageData({
+									canvasId: 'reusableCanvas',
+									x: 0,
+									y: 0,
+									width: 16,
+									height: 16,
+									success: () => {
+										this.canvasWarmed = true;
+										resolve();
+									},
+									fail: () => {
+										// 即便失败也认为已尝试过，避免反复预热阻塞流程
+										this.canvasWarmed = true;
+										resolve();
+									}
+								});
+							}, 100);
+						});
+					});
+					// 额外等待，确保字体完全加载
+					await new Promise(resolve => setTimeout(resolve, 200));
+				} catch (ex) {
+					console.log("画布预热异常:", ex);
+					this.canvasWarmed = true;
+				}
+			},
+
 			/**
 			 * 复用单个Canvas处理所有文本行
 			 */
 			async drawAndGetPixels() {
+				// 首次调用先做预热，避免第一次上报缺字
+				await this.warmupCanvas();
+
 				let binaryToHex = (binaryArray) => {
 					if (!Array.isArray(binaryArray) || binaryArray.length !== 8) {
 						throw new Error("输入必须是包含8个元素的二进制数组");
@@ -92,7 +147,7 @@
 
 				let convertCharToMatrix = (imageData, item) => {
 					const charWidth = 13;
-					const charHeight = 12;
+					const charHeight = 13;
 					const pixels = [];
 					for (let i = 0; i < imageData.length; i += 4) {
 						const R = imageData[i];
@@ -123,7 +178,7 @@
 
 					// 1. 动态调整Canvas尺寸
 					this.currentCanvasWidth = 13;
-					this.currentCanvasHeight = 12;
+					this.currentCanvasHeight = 13;
 
 					// 2. 清空Canvas（绘制背景）
 					this.clearCanvas();