这里有两个具有两个不同 id 的图像。有没有办法识别插入(拖放)图像到 Canvas 的图像。(我想获取插入到 Canvas 的 id 图像) .
我正在尝试将图像详细信息(x、y、宽度、高度)发送到具有唯一图像 ID 的数据库。在 fabric js 中有没有办法做到这一点。
function initCanvas() {
$('.canvas-container').each(function(index) {
var canvasContainer = $(this)[0];
var canvasObject = $("canvas", this)[0];
var imageOffsetX, imageOffsetY;
function handleDragStart(e) {
[].forEach.call(images, function(img) {
img.classList.remove('img_dragging');
});
this.classList.add('img_dragging');
var imageOffset = $(this).offset();
imageOffsetX = e.clientX - imageOffset.left;
imageOffsetY = e.clientY - imageOffset.top;
}
function handleDragOver(e) {
if (e.preventDefault) {
e.preventDefault();
}
e.dataTransfer.dropEffect = 'copy';
return false;
}
function handleDragEnter(e) {
this.classList.add('over');
}
function handleDragLeave(e) {
this.classList.remove('over');
}
function handleDrop(e) {
e = e || window.event;
if (e.preventDefault) {
e.preventDefault();
}
if (e.stopPropagation) {
e.stopPropagation();
}
var img = document.querySelector('.furniture img.img_dragging');
console.log('event: ', e);
var offset = $(canvasObject).offset();
var y = e.clientY - (offset.top + imageOffsetY);
var x = e.clientX - (offset.left + imageOffsetX);
var newImage = new fabric.Image(img, {
width: img.width,
height: img.height,
left: x,
top: y
});
canvas.add(newImage);
return false;
}
function handleDragEnd(e) {
[].forEach.call(images, function(img) {
img.classList.remove('img_dragging');
});
}
var images = document.querySelectorAll('.furniture img');
[].forEach.call(images, function(img) {
img.addEventListener('dragstart', handleDragStart, false);
img.addEventListener('dragend', handleDragEnd, false);
});
canvasContainer.addEventListener('dragenter', handleDragEnter, false);
canvasContainer.addEventListener('dragover', handleDragOver, false);
canvasContainer.addEventListener('dragleave', handleDragLeave, false);
canvasContainer.addEventListener('drop', handleDrop, false);
});
}
initCanvas();
var canvas = new fabric.Canvas('canvas1', {
selection: false
});
<div class="fullpage">
<div class="section">
<div class="canvas-container">
<canvas id="canvas1" style="border: 1px solid;width: 500px;height: 500px"></canvas>
</div>
<div class="furniture" style="padding: 20px;border: 1px solid;width: 460px">
<h3>Drag the image to canvas</h3>
<img id="pic1" draggable="true" src="https://www.mve.com/media/Move_logo_-01.png" width="60">
<img id="pic2" draggable="true" src="https://young.scot/media/8787/second-chances-logo-802x644.png" width="60">
</div>
</div>
</div>
<script src='https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.6/fabric.min.js'></script>
最佳答案
您可以从被拖动的元素中获取id,并添加为图像对象的属性。
function initCanvas() {
$('.canvas-container').each(function(index) {
var canvasContainer = $(this)[0];
var canvasObject = $("canvas", this)[0];
var imageOffsetX, imageOffsetY;
function handleDragStart(e) {
[].forEach.call(images, function(img) {
img.classList.remove('img_dragging');
});
this.classList.add('img_dragging');
var imageOffset = $(this).offset();
imageOffsetX = e.clientX - imageOffset.left;
imageOffsetY = e.clientY - imageOffset.top;
}
function handleDragOver(e) {
if (e.preventDefault) {
e.preventDefault();
}
e.dataTransfer.dropEffect = 'copy';
return false;
}
function handleDragEnter(e) {
this.classList.add('over');
}
function handleDragLeave(e) {
this.classList.remove('over');
}
function handleDrop(e) {
e = e || window.event;
if (e.preventDefault) {
e.preventDefault();
}
if (e.stopPropagation) {
e.stopPropagation();
}
var img = document.querySelector('.furniture img.img_dragging');
//console.log('event: ', e);
var offset = $(canvasObject).offset();
var y = e.clientY - (offset.top + imageOffsetY);
var x = e.clientX - (offset.left + imageOffsetX);
var newImage = new fabric.Image(img, {
width: img.width,
height: img.height,
left: x,
top: y,
id: img.id
});
canvas.add(newImage);
console.log(newImage.id)
return false;
}
function handleDragEnd(e) {
[].forEach.call(images, function(img) {
img.classList.remove('img_dragging');
});
}
var images = document.querySelectorAll('.furniture img');
[].forEach.call(images, function(img) {
img.addEventListener('dragstart', handleDragStart, false);
img.addEventListener('dragend', handleDragEnd, false);
});
canvasContainer.addEventListener('dragenter', handleDragEnter, false);
canvasContainer.addEventListener('dragover', handleDragOver, false);
canvasContainer.addEventListener('dragleave', handleDragLeave, false);
canvasContainer.addEventListener('drop', handleDrop, false);
});
}
initCanvas();
var canvas = new fabric.Canvas('canvas1', {
selection: false
});
<div class="fullpage">
<div class="section">
<div class="canvas-container">
<canvas id="canvas1" style="border: 1px solid;width: 500px;height: 500px"></canvas>
</div>
<div class="furniture" style="padding: 20px;border: 1px solid;width: 460px">
<h3>Drag the image to canvas</h3>
<img id="pic1" draggable="true" src="https://www.mve.com/media/Move_logo_-01.png" width="60">
<img id="pic2" draggable="true" src="https://young.scot/media/8787/second-chances-logo-802x644.png" width="60">
</div>
</div>
</div>
<script src='https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.6/fabric.min.js'></script>
关于javascript - 如何识别插入 Canvas 的 fabric js 图像对象?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51262612/