javascript – 在Canvas Fabric JS中的元素上添加删除按钮

嗨,我想使用FabricJS在元素中添加删除按钮.我有一个例子：

我尝试添加这部分代码但是当我调整图像大小时,删除按钮不会保留在原位.

http://jsfiddle.net/wxao1on8/13/

function addDeleteBtn(x,y,w){
        $(".deleteBtn").remove();
        var btnLeft = x;
        var btnTop = y - 30;
        var widthadjust=w/2;
        btnLeft=widthadjust+btnLeft-1
        var deleteBtn = '<img src="https://www.funagain.com/images/old/common/delete-icon.png" class="deleteBtn" ' +
                'style="position:absolute;top:'+btnTop+'px;right:'+btnLeft+'px;cursor:pointer;"/>';
        $(".canvas-container").append(deleteBtn);
    }

    canvas.on('object:selected',function(e){
        addDeleteBtn(e.target.oCoords.mt.x,e.target.oCoords.mt.y,e.target.width);
    });

    canvas.on('mouse:down',function(e){
        if(!canvas.getActiveObject())
        {
            $(".deleteBtn").remove();
        }
    });

    canvas.on('object:modified',e.target.width);
    });

    canvas.on('object:moving',function(e){
        $(".deleteBtn").remove();
    });

    $(document).on('click',".deleteBtn",function(){
        if(canvas.getActiveObject())
        {
            canvas.remove(canvas.getActiveObject());
            $(".deleteBtn").remove();
        }
    });

解决方法

target.oCoords.mt是中上角.

请改用右上角：e.target.oCoords.tr

var canvas = new fabric.Canvas('canvas');
var HideControls = {
            'tl':true,'tr':false,'bl':true,'br':true,'ml':true,'mt':true,'mr':true,'mb':true,'mtr':true
        };
fabric.Image.fromURL('http://serio.piiym.net/CVBla/txtboard/thumb/1260285874089s.jpg',function (img) {
    img.top = 60;
    img.left = 30;
    img.setControlsVisibility(HideControls);
    canvas.add(img);
});

canvas.renderAll();

function addDeleteBtn(x,y){
    $(".deleteBtn").remove(); 
    var btnLeft = x-10;
    var btnTop = y-10;
    var deleteBtn = '<img src="https://www.funagain.com/images/old/common/delete-icon.png" class="deleteBtn" style="position:absolute;top:'+btnTop+'px;left:'+btnLeft+'px;cursor:pointer;width:20px;height:20px;"/>';
    $(".canvas-container").append(deleteBtn);
}

canvas.on('object:selected',function(e){
        addDeleteBtn(e.target.oCoords.tr.x,e.target.oCoords.tr.y);
});

canvas.on('mouse:down',function(e){
    if(!canvas.getActiveObject())
    {
        $(".deleteBtn").remove(); 
    }
});

canvas.on('object:modified',function(e){
    addDeleteBtn(e.target.oCoords.tr.x,e.target.oCoords.tr.y);
});

canvas.on('object:scaling',function(e){
    $(".deleteBtn").remove(); 
});
canvas.on('object:moving',function(e){
    $(".deleteBtn").remove(); 
});
canvas.on('object:rotating',function(e){
    $(".deleteBtn").remove(); 
});
$(document).on('click',function(){
    if(canvas.getActiveObject())
    {
        canvas.remove(canvas.getActiveObject());
        $(".deleteBtn").remove();
    }
});