添加了单击按钮时添加放大镜(.img-magnifier-glass)的功能。现在,我想通过单击“取消”按钮来移除玻璃。我对如何编写此函数以与“放大”函数一起使用感到困惑。

我试图创建一个添加一个类的函数,该类在“ .img-magnifier-glass”上为“ display:none”。



function magnify(imgID, zoom)
{
    var img, glass, w, h, bw;
    img = document.getElementById(imgID);
    /*create magnifier glass:*/
    glass = document.createElement("DIV");
    glass.setAttribute("class", "img-magnifier-glass");
    /*insert magnifier glass:*/
    img.parentElement.insertBefore(glass, img);
    /*set background properties for the magnifier glass:*/
    glass.style.backgroundImage = "url('" + img.src + "')";
    glass.style.backgroundRepeat = "no-repeat";
    glass.style.backgroundSize = (img.width * zoom) + "px " + (img.height * zoom) + "px";
    bw = 3;
    w = glass.offsetWidth / 2;
    h = glass.offsetHeight / 2;

    /*execute a function when someone moves the magnifier glass over the image:*/
    glass.addEventListener("mousemove", moveMagnifier);
    img.addEventListener("mousemove", moveMagnifier);
    /*and also for touch screens:*/
    glass.addEventListener("touchmove", moveMagnifier);
    img.addEventListener("touchmove", moveMagnifier);
    function moveMagnifier(e)
    {
        var pos, x, y;
        /*prevent any other actions that may occur when moving over the image:*/
        e.preventDefault();
        /*get the cursor's x and y positions:*/
        pos = getCursorPos(e);
        x = pos.x;
        y = pos.y;
        /*prevent the magnifier glass from being positioned outside the image:*/
        if (x > img.width - (w / zoom)) { x = img.width - (w / zoom); }
        if (x < w / zoom) { x = w / zoom; }
        if (y > img.height - (h / zoom)) { y = img.height - (h / zoom); }
        if (y < h / zoom) { y = h / zoom; }
        /*set the position of the magnifier glass:*/
        glass.style.left = (x - w) + "px";
        glass.style.top = (y - h) + "px";
        /*display what the magnifier glass "sees":*/
        glass.style.backgroundPosition = "-" + ((x * zoom) - w + bw) + "px -" + ((y * zoom) - h + bw) + "px";
    }
    function getCursorPos(e)
    {
        var a, x = 0, y = 0;
        e = e || window.event;
        /*get the x and y positions of the image:*/
        a = img.getBoundingClientRect();
        /*calculate the cursor's x and y coordinates, relative to the image:*/
        x = e.pageX - a.left;
        y = e.pageY - a.top;
        /*consider any page scrolling:*/
        x = x - window.pageXOffset;
        y = y - window.pageYOffset;
        return { x: x, y: y};
    }
}


function onClick()
{
    magnify("img1", 1.5);
    magnify("img2", 1.5);
    magnify("img4", 1.5);
}

<div>
  <div class="slideshow-container">
      <button onclick = "onClick()" id="btn1" type="button" class="btn"> Zoom In</button>
        <button onclick = "zoomOut()" id= "btn2" type= "button" class="btn" >Cancel</button>
      <div class="img-magnifier-container mySlides">
        <img id = "img1" src="img1.jpg" width="800" height="600">
      </div>
      <div class="img-magnifier-container mySlides">
        <img id = "img2" src="img2.jpg" width="800" height="600" >
      </div>
      <div class="img-magnifier-container mySlides">
        <img id = "img4" src="img4.jpg" width="800" height="600">
      </div>
  </div>

最佳答案

您需要找到添加的元素并将其删除。由于缩放脚本为他们提供了所有img-magnifier-glass的类名,因此您可以执行以下操作:

function zoomOut() {
   var zooms = document.querySelectorAll(".img-magnifier-glass");
   for(var x=0;x<zooms.length;x++) {
      zooms[x].parentNode.removeChild(zooms[x]);
   }
}

关于javascript - 从图像上取下放大镜,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/54030142/

10-11 12:35
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