我是新的Angular和Fabric js所以任何指针都非常赞赏.我正在尝试构建一个用户界面,用户可以将对象拖放到画布上,然后用线条连接它们.
从本质上讲,我希望从第一个链接获得Angular4拖放示例,以便在第二个链接中找到farbricjs画布.
> Drag and Drop
> Canvas Example
拖放示例有效,但fabricjs画布在Chrome中呈现为方框,仅此而已.任何想法都非常感激.
我采取的步骤：
在tsconfig.json中我设置了“allowJs”：true
我的dnd.component.html看起来像：
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.5.0/fabric.min.js"></script>
<script type="text/javascript" src="canvas.js"></script>
<style>
canvas {
border: 1px solid #ccc;
}
</style>
<div class="container">
<div>
<simple-dnd></simple-dnd>
<canvas id="c" width="600" height="600"></canvas>
</div>
</div>
而canvas.js看起来像这样：
setTimeout(function() {
$(document).ready(function () {
var canvas = new fabric.Canvas('c',{selection: false});
var grid = 50;
// create grid
for (var i = 0; i < (600 / grid); i++) {
canvas.add(new fabric.Line([i * grid,i * grid,600],{stroke: '#ccc',selectable: false}));
canvas.add(new fabric.Line([0,600,i * grid],selectable: false}))
}
// add objects
var rect = new fabric.Rect({
left: 100,top: 100,width: 247,height: 309,fill: '#9f9',originX: 'left',originY: 'top',centeredRotation: true
});
canvas.add(rect);
var rect2 = new fabric.Rect({
left: 100,width: 223,height: 167,fill: '#faa',centeredRotation: true
});
canvas.add(rect2);
var rect3 = new fabric.Rect({
left: 196,top: 334,width: 150,height: 75,fill: 'blue',centeredRotation: true
});
canvas.add(rect3);
canvas.renderAll();
});
},0);
解决方法
我做了类似的事情.不完全使用您提供的链接.我使用fabric js以及canvas和angular4来将png文件拖放到画布上.零件：
import { Component,OnInit} from '@angular/core';
import 'fabric';
declare const fabric: any;
@Component({
selector: 'app-image-preview',templateUrl: './image-preview.component.html',styleUrls: ['./image-preview.component.styl']
})
export class ImagePreviewComponent implements OnInit {
image: any;
file:File = null;
canvas:any;
constructor() { }
ngOnInit() {
//this.context = this.canvasRef.nativeElement.getContext('2d');
this.canvas = new fabric.Canvas('canvas',{ selection: false });
}
handleDrop(e) {
this.file = e.dataTransfer.files[0];
const reader = new FileReader();
reader.onload = (imgFile) => {
console.log(imgFile)
const data = imgFile.target["result"];
fabric.Image.fromURL(data,(img) => {
let oImg = img.set({
left: 0,top: 0,angle: 0
}).scale(1);
this.canvas.add(oImg).renderAll();
var a = this.canvas.setActiveObject(oImg);
var dataURL = this.canvas.toDataURL({format: 'png',quality: 0.8});
});
};
reader.readAsDataURL(this.file);
return false;
}
HTML模板：
<div
(dragover)="false"
(dragend)="false"
(drop)="handleDrop($event)">
<canvas id="canvas" class="canvas" width="500" height="500">
</canvas>
</div>
如果您没有发现这有用,请告诉我,我可以删除答案.
