HTML - 在用户类型时保留占位符

Question

我有这样的输入:

<input value="My text" placeholder="Placeholder">

当我在输入中输入内容时,占位符文本将消失,这是非常明显的.

现在,我想要做的是我希望占位符文本在用户输入时保留,以便您可以将占位符文本看作原始文本后面的背景文本:

编辑:我也希望能够使用JavaScript更改背景文本.

Answer 1

通过CSS轻松实现更好的解决方案.看看:http://jsfiddle.net/csdtesting/wbqq129q/

• 在输入之前:

• 输入时:

码:

#login {
  font-size: 12px;
  margin: 0 auto;
  width: 700px;
}
#login li {
  float: left;
  list-style: none;
  margin-left: 30px;
  position: relative;
}
#login li:first-child {
  margin-left: 0;
}
label {
  line-height: 40px;
  position: absolute;
  right: 120px;
  top: 0;
  bottom: 0;
  -moz-transition: 0.3s right ease;
  -ms-transition: 0.3s right ease;
  -o-transition: 0.3s right ease;
  -webkit-transition: 0.3s right ease;
  transition: 0.3s right ease;
  z-index: 0
}
input {
  color: transparent;
  font-size: 12px;
  height: 35px;
  -moz-border-radius: 3px;
  -webkit-border-radius: 3px;
  border-radius: 3px;
  -moz-transition: 0.3s all ease;
  -ms-transition: 0.3s all ease;
  -o-transition: 0.3s all ease;
  -webkit-transition: 0.3s all ease;
  transition: 0.3s all ease;
}
input[type="email"],
input[type="password"] {
  border: 1px solid #ccc;
  height: 35px;
  padding: 0 10px;
  width: 240px;
  position: relative;
  -moz-box-shadow: inset 0 0 10px rgba(0, 0, 0, .06);
  -webkit-box-shadow: inset 0 0 10px rgba(0, 0, 0, .06);
  box-shadow: inset 0 0 10px rgba(0, 0, 0, .06);
  z-index: 2;
}
input[type="email"] {
  color: rgba(47, 130, 194, .8);
}
/* Placeholder */

input[type="email"]:-moz-placeholder {
  color: rgba(47, 130, 194, .6);
}
input[type="email"]:-ms-input-placeholder {
  color: rgba(47, 130, 194, .6);
}
input[type="email"]::-webkit-input-placeholder {
  color: rgba(47, 130, 194, .6);
}
/* Label */

input[type="email"] + label {
  color: rgb(47, 130, 194);
}
input:focus + label {
  right: 10px;
}
input[type="email"]:focus,
input[type="password"]:focus {
  background-color: rgba(255, 255, 255, .8);
}
/* Submit */

input[type="submit"] {
  background-color: #333;
  background: -moz-linear-gradient(bottom, #333, #444);
  background: -ms-linear-gradient(bottom, #333, #444);
  background: -o-linear-gradient(bottom, #333, #444);
  background: -webkit-linear-gradient(bottom, #333, #444);
  background: linear-gradient(bottom, #333, #444);
  border: 1px solid #222;
  color: #fff;
  cursor: pointer;
  height: 35px;
  width: 110px;
}

<form id="login">
  <ul>
    <li>
      <input id="email" name="email" placeholder="Your Email" title="Your Email" type="email" required />
      <label for="email">Your Email</label>
    </li>
  </ul>
</form>

Answer 2

很难想象这种行为的好用例,因为它阻止了一些用户输入.

一种简单的方法是使用,input::after但现在任何浏览器都不支持(感谢@ JukkaK.Korpela).

但是您可以使用包装器元素和数据属性,如下所示:

<div class="placeholder" data-placeholder="my placeholder">
    <input value="My text" />  
</div>

有了这个css:

.placeholder
{
    position: relative;
}

.placeholder::after
{
    position: absolute;
    left: 5px;
    top: 3px;
    content: attr(data-placeholder);
    pointer-events: none;
    opacity: 0.6;
}

导致:

点击这里查看jsFiddle演示.

因为你必须做很多调整才能使它看起来很好,你也可以考虑使用包装<div>元素作为输入"外观相似":

<div class="editable" data-placeholder="my placeholder">
    <input type="text" value="my Text" />
</div>

CSS:

.editable
{
    position: relative;
    border: 1px solid gray;
    padding: 3px;
    background-color: white;
    box-shadow: rgba(0,0,0,0.4) 2px 2px 2px inset;
}

.editable > input
{
    position: relative;
    z-index: 1;
    border: none;
    background-color: transparent;
    box-shadow: none;
    width: 100%;
}

.editable::after
{
    position: absolute;
    left: 4px;
    top: 5px;
    content: attr(data-placeholder);
    pointer-events: none;
    opacity: 0.5;
    z-index: 1;
}

点击这里进行演示3.(有嘲笑<input />)

点击这里进行演示2.(有满足感)