未解决在TypeScript项目中使用Path2D的问题

Question

我想在TypeScript项目中使用新的Path2D api，但在lib.es6.d.ts中看不到它。我使用它的最佳方法是什么？有人有Path2D的d.ts文件吗？

Answer 1

我花了一些时间，我为您做了声明：

我是按照相同的标准TypeScript在lib.d.ts中内部定义其接口来完成这项工作的
请注意，您可以很容易地为未来的功能扩展此代码，如果您这样做，我希望看到它在这里更新。

Path2D.d.ts（在TypeScript Playground中查看）

// Class
interface Path2D {
    addPath(path: Path2D, transform?: SVGMatrix);
    closePath(): void;
    moveTo(x: number, y: number): void;
    lineTo(x: number, y: number): void;
    bezierCurveTo(cp1x: number, cp1y: number, cp2x: number, cp2y: number, x: number, y: number): void;
    quadraticCurveTo(cpx: number, cpy: number, x: number, y: number): void;
    arc(x: number, y: number, radius: number, startAngle: number, endAngle: number, anticlockwise?: boolean): void;
    arcTo(x1: number, y1: number, x2: number, y2: number, radius: number): void;
    /*ellipse(x: number, y: number, radiusX: number, radiusY: number, rotation: number, startAngle: number, endAngle: number, anticlockwise?: boolean): void;*/
    rect(x: number, y: number, w: number, h: number): void;
}
// Constructor
interface Path2DConstructor {
    new (): Path2D;
    new (d: string): Path2D;
    new (path: Path2D, fillRule?: string): Path2D;
    prototype: Path2D;
}
declare var Path2D: Path2DConstructor;
// Extend Window 
interface Window { Path2D: Path2DConstructor; }
// Extend CanvasRenderingContext2D
interface CanvasRenderingContext2D {
    fill(path: Path2D): void;
    stroke(path: Path2D): void;
    clip(path: Path2D, fillRule?: string): void;
}

示例：

var canvas: HTMLCanvasElement = <HTMLCanvasElement>document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var path1 = new Path2D();
path1.rect(10, 10, 100, 100);
var path2 = new Path2D(path1);
path2.moveTo(220, 60);
path2.arc(170, 60, 50, 0, 2 * Math.PI);
var m = (<SVGSVGElement>document.createElementNS("http://www.w3.org/2000/svg", "svg")).createSVGMatrix();
m.a = 1; m.b = 0;
m.c = 0; m.d = 1;
m.e = 300; m.f = 0;
path2.addPath(path1, m);
ctx.stroke(path1);
ctx.fill(path2);