在Flutter中绘图非常简单。关键词CustomPainter,CustomPaint,Canvas。 在iOS/Android中我们继承UIView/View重写draw/onDraw方法在里面执行画图操作。 在Flutter中稍微有点不一样,我们使用CustomPaint(这是一个widget),它需要一个参数painter,这个参数的类型是一个抽象类CustomPainter。 我们需要实现这个类的两个关键方法:p...
Widgetbuild(BuildContext context){returnScaffold(appBar:AppBar(title:constText("Draw on Canvas"),actions:<Widget>[IconButton(icon:constIcon(Icons.clear),onPressed:()=>setState(()=>points.clear()),),IconButton(icon:constIcon(Icons.color_lens),onPressed:pickColor,),],),body:GestureDetector(on...
voidpaint(Canvascanvas,Sizesize){canvas.save();//第一处canvas.clipRRect(RRect.fromRectXY(Offset.zero&(size/2.0),50.0,50.0));//第二处canvas.drawPaint(Paint()..color=Colors.white);//第三处canvas.restore();//第四处canvas.save();//到五处canvas.clipRRect(RRect.fromRectXY(size.center(Of...
canvas.drawLine(Offset(dx, rect.top), Offset(dx, rect.bottom), paint); } } 棋子的宽高为1/15的画布大小小一点,黑子在棋盘中心的位置偏左一格,白子在棋盘中心偏右一格: //画棋子voiddrawPieces(Canvas canvas, Rect rect) {doubleeWidth = rect.width /15;doubleeHeight = rect.height /15;//画一...
void drawLine(Offset p1, Offset p2, Paint paint) 使用给定的涂料在给定点之间绘制一条线。 该行被描边,此调用忽略[Paint.style]的值。p1和p2参数为两个点的坐标 , 在这两点之间绘制一条直线。 eg : canvas.drawLine(Offset(20.0, 20.0), Offset(100.0, 100.0), _paint) ...
();Canvas canvas=Canvas(recorder,targetRect);canvas.drawColor(Colors.black,BlendMode.color);// 绘制背景图片canvas.drawImageRect(info.image,Rect.fromLTWH(0,0,960,1622),Rect.fromLTWH(bgStartDrawX,bgStartDrawY,bgDrawWidth,bgDrawHeight),paint);// 绘制大标题文本varparagraphBuilder=UI.Paragraph...
drawFrameImage(originImageUrl, frameImageUrl) ]).then((result) { Paint paint =newPaint(); PictureRecorder recorder = PictureRecorder(); Canvas canvas = Canvas(recorder); intwidth = result[0].width; intheight = result[0].height; //合成 ...
贝塞尔曲线绘制完成后调用drawShadow绘制阴影,作用是突出上下两部分连接处的效果,最后通过 path 绘制出整个上半部分的效果,如下: 下半部分 代码实现如下: 代码语言:javascript 复制 voiddrawBottom(ui.Canvas canvas){path.reset();path.moveTo(left,bottomBezierStart);path.quadraticBezierTo(centerWidth,topBezierEnd...
drawFrameImage(originImageUrl, frameImageUrl) ]).then((result) { Paint paint =newPaint; PictureRecorder recorder = PictureRecorder; Canvas canvas = Canvas(recorder); intwidth = result[0].width; intheight = result[0].height; //合成
import'dart:ui';/// 绘制抽象类abstractclassShape{voiddraw(Canvas canvas,List<Offset>points,Paint paint,);} 实现线、圆、矩形绘制 /// 绘制圆classCircleShapeimplementsShape{@overridevoiddraw(Canvas canvas,List<Offset>points,Paint paint){if(points.length>=2){double radius=(points[points.length-1]...