修改

src/components/TravelContractConfirm.vue

@@ -2674,7 +2674,7 @@
  
         dialogVisible:false,
         showCanvas:false,
-        linewidth: 3, //线条粗细，选填
+        linewidth: 10, //线条粗细，选填
         color: "black", //线条颜色，选填
         background: "#fff", //线条背景，选填
         dataList:[],
@@ -3222,7 +3222,8 @@
         el.appendChild(canvas);
         canvas.width = el.clientWidth;
         canvas.height = el.clientHeight;
-        cxt.fillStyle = this.background; //填充绘图的背景颜色
+        //cxt.fillStyle = this.background; //填充绘图的背景颜色
+        cxt.fillStyle='rgba(255, 255, 255, 0)';
         cxt.fillRect(0, 0, canvas.width, canvas.height); //绘制“已填色”的矩形
         cxt.strokeStyle = this.color; //笔触的颜色
         cxt.lineCap = "round"; //线条末端线帽的样式