Question

我想在单击某些按钮后放大一些切换图像。但是，放大的图像似乎始终是第一个。有人可以帮助我吗？

该问题应该从JS代码的底部开始，请参阅随附的代码。

此外，我想知道是否需要将magnify（）合并到onclick函数中

感谢您的耐心配合，乔

我已经厌倦了在函数中添加magnify（），但似乎也无法正常工作。

function softtissue(){
  document.getElementById("img-imgmap201293016112").src="images/Cases/softtissue/32.jpg";
}

function bone(){
  document.getElementById("img-imgmap201293016112").src="images/Cases/bone/32.jpg"; 
}

function lung(){
  document.getElementById("img-imgmap201293016112").src="images/Cases/lung/32.jpg";
}

magnify('img-imgmap201293016112',3);

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};
  }
}

/*Qustion begain here*/
function activatemagnify(){
 var dis= document.getElementsByClassName("img-magnifier-glass");
	if( dis [0].style.visibility==="hidden"){
		dis [0].style.visibility="visible";
	}
	else{
		dis [0].style.visibility="hidden";
	}
	
}

function softtissue(){
	
	document.getElementById("img-imgmap201293016112").src="http://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Starry_Night_Over_the_Rhone.jpg/200px-Starry_Night_Over_the_Rhone.jpg";
}

function bone(){
	
	document.getElementById("img-imgmap201293016112").src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Vincent_van_Gogh_-_Sunflowers_-_VGM_F458.jpg/183px-Vincent_van_Gogh_-_Sunflowers_-_VGM_F458.jpg";	

}
function lung(){
		document.getElementById("img-imgmap201293016112").src="https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Vincent_van_Gogh_-_Self-Portrait_-_Google_Art_Project_%28454045%29.jpg/190px-Vincent_van_Gogh_-_Self-Portrait_-_Google_Art_Project_%28454045%29.jpg";

}
	magnify('img-imgmap201293016112',3);

{box-sizing: border-box;}

.img-magnifier-container {
  position:relative;
}

.img-magnifier-glass { 
  visibility: hidden;
  position: absolute;
  border: 3px solid #000;
  border-radius: 50%;
  cursor: none;
  /*Set the size of the magnifier glass:*/
  width: 100px;
  height: 100px;
}

<html>
<meta name="viewport" content="width=device-width, initial-scale=1.0">

<body>
<div class="img-magnifier-container">
  <img id="img-imgmap201293016112" src="http://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Starry_Night_Over_the_Rhone.jpg/200px-Starry_Night_Over_the_Rhone.jpg" width="600" height="400">
</div>
<br/><br/><br/><br/>
<div style="z-index:3">
<button id="softtissue" type="button" onclick="softtissue();return false" class="button">
  Soft Tissue</button>
  <button id="bone" type="button" onclick="bone(); return false;" class="button">
	Bone</button>
  <button id="lung" type="button" onclick="lung()" class="button">
	Lung</button>
<button onclick="activatemagnify()" type="button" class="button">
	Magnify</button>
  </div>
  </body>
  </html>

Answer 1

您的代码的主要问题是，包含缩放图像的图像是在首次加载时创建的，之后不会更改。

如果在图像上添加img.onload=function()并在加载基本图像后立即更新缩放的图像，则会得到一个工作放大镜。您还应该设置glass.style.visibility="hidden"，否则必须单击两次以显示变焦镜头。

这是需要更改的代码部分：

function magnify(imgID, zoom) {
  var img, glass, w, h, bw;
  img = document.getElementById(imgID);
  var prevImgs= document.getElementsByClassName("img-magnifier-glass");
  // remove the old lense ...
  if (prevImgs.length>0) {
    prevImgs[0].remove();
  }
  /*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 + "')";
  console.log(img.src);
  glass.style.backgroundRepeat = "no-repeat";
  glass.style.visibility = "hidden";
  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);

  ...
}

而不是一次调用magnify(...);，而是在图像加载完成时调用它：

document.getElementById("img-imgmap201293016112").onload = function() {
  magnify('img-imgmap201293016112', 3);
}

这是显示工作放大镜的Fiddle。

启动功能后按其ID检索正确的图像

1 个答案: