// 创建 canvas 绘图上下文对象
       const context = wx.createCanvasContext('screenCanvas');
	   //要绘制海报用到的图片
	   const imageUrl="/static/images/family.jpg"
	   //小程序二维码
	   const imageUrl1="/static/images/erCode.png"
	   // 绘制图片到canvas
	   context.drawImage(imageUrl, 0, 0,  canvasWidth.value,canvasHeight.value*0.6)
	   //开始绘制线条
	   context.beginPath();
	   //定位到线条起始点
	   context.moveTo(0, canvasHeight.value * 0.5);
	   //拉一条线到中间坐标
	   // context.lineTo(0, canvasHeight.value * 0.5);
	   //绘制圆弧从x轴0.25-0.5，y轴:0.6-0.6不严谨但是效果一样弧度为300
	   context.arcTo(canvasWidth.value / 4, canvasHeight.value * 0.6, canvasWidth.value * 0.5, canvasHeight.value * 0.6,canvasHeight.value-canvasHeight.value * 0.6 );
	   //绘制圆弧从x轴0.75-1，y轴:0.6-0.5不严谨但是效果一样弧度为300
	   context.arcTo(canvasWidth.value * 0.75, canvasHeight.value * 0.6, canvasWidth.value, canvasHeight.value * 0.5,canvasHeight.value-canvasHeight.value * 0.6 );
	   // 划线从(1,0.5)开始
	   context.lineTo(canvasWidth.value, canvasHeight.value * 0.5);
	   // 划线从(1,0.5)开始-（1，1）
	   context.lineTo(canvasWidth.value, canvasHeight.value);
	   // 划线从（1，1）-(0,1)
	   context.lineTo(0, canvasHeight.value);
	   // 划线从(0,1)-(0,0.5)
	   context.lineTo(0, canvasHeight.value*0.5);
	   //绘制完成设置填充色
	   context.fillStyle = "rgb(255, 128, 0)";
	   //开始填充
	   context.fill();
	   context.closePath()
	   //判断缩放比例二维码
	   const a=canvasWidth.value/710
	   const b=canvasHeight.value/674
	   // 对比比例哪个小就以哪个为标准缩放
	   const scX=a>b?b:a
	   //这里缩放后除以2是为了以基准宽的0.5作为二维码宽度
	   const width=710*scX/2
	   const height=674*scX/2
	   //动态绘制二维码到指定位置与canvas的比例可能发生改变但是不会发生形变
	  context.drawImage(imageUrl1,0, 0,710,674, canvasWidth.value / 2 -width/2, canvasHeight.value*0.65-height/2, width, height);
	  context.closePath();
	  //开始绘制文字
	  context.beginPath();
	  //设置颜色
	  context.fillStyle = "rgb(255, 85, 0)";
	  // 设置字体样式
	  context.font='italic bold 33px Microsoft Yahei'
	  //字体内容
	  context.fillText('速达·陪诊', canvasWidth.value / 10, canvasHeight.value/2.6)
	  context.font='italic bold 30px Microsoft Yahei'
	  context.fillText('快速·必达', canvasWidth.value / 2, canvasHeight.value/2.2)
	  context.closePath();
	  context.fillStyle = "rgb(255, 255, 255)";
	  context.font='18rpx Microsoft Yahei'
	  //动态可修改文字内容
	  const len=btText1.value.length/2
	  context.fillText(btText1.value, canvasWidth.value /2-20*len, canvasHeight.value-50)
	  context.font="18rpx Microsoft Yahei"
	  context.fillText(btText2.value, canvasWidth.value / 2-20*len, canvasHeight.value-25)
	   //绘制并保留上面的内容
	   context.draw(true)
	   // 开始绘制
       context.draw(true, function() {
         // 将 canvas 保存为临时图片
         wx.canvasToTempFilePath({
           canvasId: 'screenCanvas',
           destWidth: canvasWidth.value,
           destHeight: canvasHeight.value,
           success: function (res) {
             tempFilePath.value = res.tempFilePath;
             wx.showToast({
               title: '生成成功',
               icon: 'success',
               duration: 2000
             })
           },
           fail: function (res) {
             wx.showToast({
               title: '生成失败',
               icon: 'none',
               duration: 2000
             })
           }
         })
       });
 }
 
 

// 获取屏幕宽高并根据设计稿动态的改变canvas的宽高
		   wx.getSystemInfo({
		     success: (res) => {
				 scale.value=Math.min(res.screenWidth / 375, res.screenHeight / 603);
				 drp.value=res.pixelRatio
		         canvasWidth.value=Math.floor(375*scale.value)
		         canvasHeight.value=Math.floor(603*scale.value)
				 isHuawei.value=res.brand=="HUAWEI"
		     }
		   })