if(this.select.selectElementIndex!==-1){// 获取选择元素的矩形属性,绘制框选效果constrect=this.select.getCurSelectElement().rectdrawResizeRect(this.context,rect)}/*** 绘制拖拽矩形*/exportconstdrawResizeRect=(context:CanvasRenderingContext2D,rect:ElementRect)=>{const{x,y,width,height}=rectcontext....
width和height设置矩形的尺寸。 functiondraw(){varcanvas=document.getElementById('canvas');if(canvas.getContext){varctx=canvas.getContext('2d');ctx.fillRect(25,25,100,100);//默认会用黑色填充ctx.clearRect(45,45,60,60);//区域被清除,透明ctx.strokeRect(50,50,50,50);//默认边框为黑色}} im...
<input type="range" name="point" min="0.2" max="2" step="0.2" value="1"/> <canvas id="draw" width="345" height="310" style="border:1px solid #CCC"></canvas> JS var canvas =document.getElementById('draw'); var ctx = canvas.getContext('2d'); var point = document.querySele...
DOCTYPE html><htmllang="en"><head><metacharset="UTF-8"><title>使用带有基本备用内容的canvas元素</title><style>canvas{border:medium double black;margin:4px;}</style></head><body><canvaswidth="500"height="200">Your browser doesn't support the<code>canvas</code>element</canvas></body></...
draw();canvasElement.onmousemove=function(e){if(e.ctrlKey){ point1=[e.clientX, e.clientY]; }elseif(e.shiftKey){ point2=[e.clientX, e.clientY]; }else{ point3=[e.clientX, e.clientY]; } ctx.clearRect(0,0,500,140); draw(); ...
drawImage(bird,0,0,50,50);ctx.restore();// 恢复 canvas 状态window.requestAnimationFrame(draw)...
原生渲染是由VSYNC信号进行驱动,通过ViewRootImpl#PerformTraversal顶级函数触发测量(Measure)、布局(Layout)、绘制(Draw)流程,以绘制为例,消息首先分发到根视图DecorView,并自顶向下分发(dispatchDraw)依次回调每个View的onDraw函数。 对于FCanvas PlatformView来说,它是一个TextureView,其本质上是一个SurfaceTexture,当...
当前扇形半径this.hoverRadius=170this.pieIndex=-1}// 初始化PieChart.prototype.init=function(data,pointer,click){// 1、准备数据this.drawPie(data,pointer,click)}// 画饼图PieChart.prototype.drawPie=function(data,pointer,click){letthat=this;// 1、转化弧度letangleList=this.transformAngle(data)//...
if (this.select.selectElementIndex !== -1) { // 获取选择元素的矩形属性,绘制框选效果 const rect = this.select.getCurSelectElement().rect drawResizeRect(this.context, rect) } /** * 绘制拖拽矩形 */ export const drawResizeRect = ( ...
<canvas id="canvas"height="800"width="900"></canvas><script>constcanvas=document.getElementById('canvas')constctx=canvas.getContext('2d')// 绘制时钟显示之前的文本提示:ctx.font='50px s'ctx.textAlign='center'ctx.strokeText('你即将看到时钟',450,400,400)// 绘制时钟:functiondraw(){// 获取...