鼠标悬停缩放图像仅在鼠标悬停时显示

Question

我制作了这个鼠标悬停图像缩放页面。但我希望输出显示在左侧，并且仅当有人将鼠标悬停在其上时。在此代码中，输出 window 不断打开。

这是我的代码：

function imageZoom(imgID, resultID) {
  var img, lens, result, cx, cy;
  img = document.getElementById(imgID);
  result = document.getElementById(resultID);
  /*create lens:*/
  lens = document.createElement("DIV");
  lens.setAttribute("class", "img-zoom-lens");
  /*insert lens:*/
  img.parentElement.insertBefore(lens, img);
  /*calculate the ratio between result DIV and lens:*/
  cx = result.offsetWidth / lens.offsetWidth;
  cy = result.offsetHeight / lens.offsetHeight;
  /*set background properties for the result DIV:*/
  result.style.backgroundImage = "url('" + img.src + "')";
  result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px";
  /*execute a function when someone moves the cursor over the image, or the lens:*/
  lens.addEventListener("mousemove", moveLens);
  img.addEventListener("mousemove", moveLens);
  /*and also for touch screens:*/
  lens.addEventListener("touchmove", moveLens);
  img.addEventListener("touchmove", moveLens);

  function moveLens(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);
    /*calculate the position of the lens:*/
    x = pos.x - (lens.offsetWidth / 2);
    y = pos.y - (lens.offsetHeight / 2);
    /*prevent the lens from being positioned outside the image:*/
    if (x > img.width - lens.offsetWidth) {
      x = img.width - lens.offsetWidth;
    }
    if (x < 0) {
      x = 0;
    }
    if (y > img.height - lens.offsetHeight) {
      y = img.height - lens.offsetHeight;
    }
    if (y < 0) {
      y = 0;
    }
    /*set the position of the lens:*/
    lens.style.left = x + "px";
    lens.style.top = y + "px";
    /*display what the lens "sees":*/
    result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "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
    };
  }
}

// Initiate zoom effect:
imageZoom("myimage", "myresult");

* {
  box-sizing: border-box;
}

.img-zoom-container {
  position: relative;
}

.img-zoom-lens {
  position: absolute;
  border: 1px solid #d4d4d4;
  /*set the size of the lens:*/
  width: 40px;
  height: 40px;
}

.img-zoom-result {
  border: 1px solid #d4d4d4;
  /*set the size of the result div:*/
  width: 300px;
  height: 300px;
}

<h1>Image Zoom</h1>

<p>Mouse over the image:</p>

<div class="img-zoom-container">
  <img id="myimage" src="img_girl.jpg" width="300" height="240">
  <div id="myresult" class="img-zoom-result"></div>
</div>

<p>The image must be placed inside a container with relative positioning.</p>
<p>The result can be put anywhere on the page, but must have the class name "img-zoom-result".</p>
<p>Make sure both the image and the result have IDs. These IDs are used when a javaScript initiates the zoom effect.</p>

代码运行完美，但结果应该在右侧，并且应该仅在用户将鼠标悬停在其上时显示。

Answer 1

默认不透明度：0；并在 mouseenter 上通过设置不透明度使其可见：1;

function imageZoom(imgID, resultID) {
  var img, lens, result, cx, cy;
  img = document.getElementById(imgID);
  result = document.getElementById(resultID);
  /*create lens:*/
  lens = document.createElement("DIV");
  lens.setAttribute("class", "img-zoom-lens");
  /*insert lens:*/
  img.parentElement.insertBefore(lens, img);
  /*calculate the ratio between result DIV and lens:*/
  cx = result.offsetWidth / lens.offsetWidth;
  cy = result.offsetHeight / lens.offsetHeight;
  /*set background properties for the result DIV:*/
  result.style.backgroundImage = "url('" + img.src + "')";
  result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px";
  /*execute a function when someone moves the cursor over the image, or the lens:*/
  lens.addEventListener("mousemove", moveLens);
  img.addEventListener("mousemove", moveLens);
  /*and also for touch screens:*/
  lens.addEventListener("touchmove", moveLens);
  img.addEventListener("touchmove", moveLens);

  function moveLens(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);
    /*calculate the position of the lens:*/
    x = pos.x - (lens.offsetWidth / 2);
    y = pos.y - (lens.offsetHeight / 2);
    /*prevent the lens from being positioned outside the image:*/
    if (x > img.width - lens.offsetWidth) {
      x = img.width - lens.offsetWidth;
    }
    if (x < 0) {
      x = 0;
    }
    if (y > img.height - lens.offsetHeight) {
      y = img.height - lens.offsetHeight;
    }
    if (y < 0) {
      y = 0;
    }
    /*set the position of the lens:*/
    lens.style.left = x + "px";
    lens.style.top = y + "px";
    /*display what the lens "sees":*/
    result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "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
    };
  }
}
imageZoom("myimage", "myresult");

function show(x) {
  document.getElementById('myresult').style.opacity = 1;
}

* {
  box-sizing: border-box;
}

.img-zoom-container {
  position: relative;
  display: flex;
}

.img-zoom-lens {
  position: absolute;
  border: 1px solid #d4d4d4;
  /*set the size of the lens:*/
  width: 70px;
  height: 70px;
}

#myresult {
  opacity: 0;
}

.img-zoom-result {
  border: 1px solid #d4d4d4;
  /*set the size of the result div:*/
  width: 300px;
  height: auto;
}

<h1>Image Zoom</h1>

<p>Mouse over the image:</p>

<div class="img-zoom-container">
  <img onmouseenter="show()" id="myimage" src="https://i.pinimg.com/originals/f8/b6/9e/f8b69e6156999b84137f3f0a23701b75.jpg" width="300" height="240">
  <div id="myresult" class="img-zoom-result"></div>
</div>

<p>The image must be placed inside a container with relative positioning.</p>
<p>The result can be put anywhere on the page, but must have the class name "img-zoom-result".</p>
<p>Make sure both the image and the result have IDs. These IDs are used when a javaScript initiates the zoom effect.</p>
// Initiate zoom effect:

Answer 2

下面我修改了你的CSS。 display: flex 就是你所追求的。

然后我得到你的代码来隐藏 result 元素并且只在 mouseover 上显示它。然后我将它隐藏在 mouseout.

您可以调整 CSS 等以匹配您的风格，但这里是我为您准备的片段；

function imageZoom(imgID, resultID) {
  var img, lens, result, cx, cy;
  img = document.getElementById(imgID);
  result = document.getElementById(resultID);
  /*create lens:*/
  lens = document.createElement("DIV");
  lens.setAttribute("class", "img-zoom-lens");
  /*insert lens:*/
  img.parentElement.insertBefore(lens, img);
  /*calculate the ratio between result DIV and lens:*/
  cx = result.offsetWidth / lens.offsetWidth;
  cy = result.offsetHeight / lens.offsetHeight;
  /*set background properties for the result DIV:*/
  result.style.backgroundImage = "url('" + img.src + "')";
  result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px";
  /*execute a function when someone moves the cursor over the image, or the lens:*/
  lens.addEventListener("mousemove", moveLens);
  img.addEventListener("mousemove", moveLens);
  /*and also for touch screens:*/
  lens.addEventListener("touchmove", moveLens);
  img.addEventListener("touchmove", moveLens);
  
  /*initialise and hide lens result*/
  result.style.display = "none";
  /*Reveal and hide on mouseover or out*/
  lens.onmouseover = function(){result.style.display = "block";};
  lens.onmouseout = function(){result.style.display = "none";};
  
  function moveLens(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);
    /*calculate the position of the lens:*/
    x = pos.x - (lens.offsetWidth / 2);
    y = pos.y - (lens.offsetHeight / 2);
    /*prevent the lens from being positioned outside the image:*/
    if (x > img.width - lens.offsetWidth) {x = img.width - lens.offsetWidth;}
    if (x < 0) {x = 0;}
    if (y > img.height - lens.offsetHeight) {y = img.height - lens.offsetHeight;}
    if (y < 0) {y = 0;}
    /*set the position of the lens:*/
    lens.style.left = x + "px";
    lens.style.top = y + "px";
    /*display what the lens "sees":*/
    result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "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};
  }
};

imageZoom("myimage", "myresult");

* {box-sizing: border-box;}

.img-zoom-container {
  position: relative;
  display: flex;
}

.img-zoom-lens {
  position: absolute;
  border: 1px solid #d4d4d4;
  /*set the size of the lens:*/
  width: 40px;
  height: 40px;
}

.img-zoom-result {
  border: 1px solid #d4d4d4;
  position: absolute;
  left: 300px; /*match width of #myimage*/
  /*set the size of the result div:*/
  width: 300px;
  height: 300px;
}

<h1>Image Zoom</h1>

<p>Mouse over the image:</p>

<div class="img-zoom-container">
  <img id="myimage" src="https://hatrabbits.com/wp-content/uploads/2018/10/risky-assumptions.jpg" width="300" height="240">
  <div id="myresult" class="img-zoom-result" style=""></div>
</div>

<p>The image must be placed inside a container with relative positioning.</p>
<p>The result can be put anywhere on the page, but must have the class name "img-zoom-result".</p>
<p>Make sure both the image and the result have IDs. These IDs are used when a javaScript initiates the zoom effect.</p>

如果您愿意，我可以努力使镜头结果绝对定位并对齐，这样您就不会在底部看到文字跳动。除非您知道如何做所有这些 - 希望这就足够了？

鼠标悬停缩放图像仅在鼠标悬停时显示

Mouse hover zoom image to be only shown when mouse hovered

html

javascript

css

mousehover