如何通过外部 css 设置 [input=image] 的 src 属性

Question

我想显示带有输入 type=image 的 html。我为图像使用 base64 svg 字符串。在输入属性 src 中设置 src 时 - 它工作正常 (btn1).

当通过外部 css 设置 src 和设置图像 class 时，它不起作用。

我尝试了 2 个不同的选项 btn2、bt3。

<html>
    <style>
        .img2 {
            src: "data:image/svg+xml;base64,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";
        }
        .img3 {
            src: url("data:image/svg+xml;base64,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");
        }
    </style>
    <body>
        <input id="imgBtn1" type="image" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9ImN1cnJlbnRDb2xvciIgc3Ryb2tlLXdpZHRoPSIyIiBzdHJva2UtbGluZWNhcD0icm91bmQiIHN0cm9rZS1saW5lam9pbj0icm91bmQiIGNsYXNzPSJmZWF0aGVyIGZlYXRoZXItcmVmcmVzaC1jY3ciPjxwb2x5bGluZSBwb2ludHM9IjEgNCAxIDEwIDcgMTAiPjwvcG9seWxpbmU+PHBvbHlsaW5lIHBvaW50cz0iMjMgMjAgMjMgMTQgMTcgMTQiPjwvcG9seWxpbmU+PHBhdGggZD0iTTIwLjQ5IDlBOSA5IDAgMCAwIDUuNjQgNS42NEwxIDEwbTIyIDRsLTQuNjQgNC4zNkE5IDkgMCAwIDEgMy41MSAxNSI+PC9wYXRoPjwvc3ZnPg==" alt="Opss">
        <label for="imgBtn1">btn1 - att src</label>
        <br>
        <input id="imgBtn2" type="image" class="img2" alt="Opss">
        <label for="imgBtn2">btn2 - by css class</label>
        <br>
        <input id="imgBtn3" type="image" class="img3" alt="Opss">
        <label for="imgBtn3">btn3 - by css class</label>
    </body>
</html>

请指教

Answer 1

既然 CSS 不是必须，那么 javascript 就是来完成这项工作的。

示例，将您的 dataUri 设置在一个数组中，并在您的输入上循环以更新 src 属性：

// set an array with each of your dataUris
const img =new Array ('data:image/svg+xml;base64,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' ,
' data:image/svg+xml;base64,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',

'data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9ImN1cnJlbnRDb2xvciIgc3Ryb2tlLXdpZHRoPSIyIiBzdHJva2UtbGluZWNhcD0icm91bmQiIHN0cm9rZS1saW5lam9pbj0icm91bmQiIGNsYXNzPSJmZWF0aGVyIGZlYXRoZXItcmVmcmVzaC1jY3ciPjxwb2x5bGluZSBwb2ludHM9IjEgNCAxIDEwIDcgMTAiPjwvcG9seWxpbmU+PHBvbHlsaW5lIHBvaW50cz0iMjMgMjAgMjMgMTQgMTcgMTQiPjwvcG9seWxpbmU+PHBhdGggZD0iTTIwLjQ5IDlBOSA5IDAgMCAwIDUuNjQgNS42NEwxIDEwbTIyIDRsLTQuNjQgNC4zNkE5IDkgMCAwIDEgMy41MSAxNSI+PC9wYXRoPjwvc3ZnPg==');

// reset src attributes from dataUri stored in img()
let myIpts =document.querySelectorAll('input[id^="imgBtn"]');
for (i = 0; i < myIpts.length; i++) {
  myIpts[i].setAttribute('src', img[i] );
}

<html>
<style>

</style>

<body>
  <input id="imgBtn1" type="image" src="data:image/svg+xml;base64,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"
    alt="Opss">
  <label for="imgBtn1">btn1 - att src</label>
  <br>
  <input id="imgBtn2" type="image" class="img2" alt="Opss">
  <label for=" imgBtn2 ">btn2 - by css class</label>
  <br>
  <input id="imgBtn3" type="image" class="img3" alt="Opss">
  <label for="imgBtn3 ">btn3 - by css class</label>
</body>

</html>

Answer 2

<img> src 属性不是可以使用 CSS 设置样式的属性。

如果你真的需要用CSS设置按钮的样式，你可以这样做：

它涉及到使用伪元素来掩盖<input>的内容并将其背景设置为SVG图像。

这有点 hacky，因为它要求您事先知道 imput 元素背后的背景颜色是什么。而且它几乎肯定需要是纯色。

#imgBtn2, #imgBtn3
{
  position: relative;
  width: 24px;
  height: 24px;
  color: transparent; /* hide alt text */
}

#imgBtn2::before, #imgBtn3::before
{
  content: '';
  display: block;
  width: 24px;
  height: 24px;
  position: absolute;
  background-color: white;
  background-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9ImN1cnJlbnRDb2xvciIgc3Ryb2tlLXdpZHRoPSIyIiBzdHJva2UtbGluZWNhcD0icm91bmQiIHN0cm9rZS1saW5lam9pbj0icm91bmQiIGNsYXNzPSJmZWF0aGVyIGZlYXRoZXItcmVmcmVzaC1jY3ciPjxwb2x5bGluZSBwb2ludHM9IjEgNCAxIDEwIDcgMTAiPjwvcG9seWxpbmU+PHBvbHlsaW5lIHBvaW50cz0iMjMgMjAgMjMgMTQgMTcgMTQiPjwvcG9seWxpbmU+PHBhdGggZD0iTTIwLjQ5IDlBOSA5IDAgMCAwIDUuNjQgNS42NEwxIDEwbTIyIDRsLTQuNjQgNC4zNkE5IDkgMCAwIDEgMy41MSAxNSI+PC9wYXRoPjwvc3ZnPg==");
}

<input id="imgBtn1" type="image" src="data:image/svg+xml;base64,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" alt="Opss">
<label for="imgBtn1">btn1 - att src</label>
<br>
<input id="imgBtn2" type="image" class="img2" alt="Opss">
<label for="imgBtn2">btn2 - by css class</label>
<br>
<input id="imgBtn3" type="image" class="img3" alt="Opss">
<label for="imgBtn3">btn3 - by css class</label>

更新

如果您不需要 <input type="image/>，那么我建议您只使用 <button> 元素。然后你就可以设置背景样式了。

在这里，我们将按钮样式与按钮图标的 CSS class 分开。所以如果你有相同类型的不同图标的按钮，你可以重复使用 class imgButton 并给它一个不同的图标 class.

.imgBtn
{
  border: none;
  width: 24px;
  height: 24px;
  background-color: transparent;

}

.reload
{
  background-image: url("data:image/svg+xml;base64,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");
}

<button type="button" class="imgBtn reload"/>

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