没有背景图片的解决方案:

.icon { padding-left: 25 px; 背景:url(“https://static.thenounproject.com/png/101791-200.png”)无重复左; background-size: 20 px; ｝ <input type="text" class="icon" value placeholder="Search">

或者从右到左的图标

.icon-rtl { padding-right: 25 px; 背景:url(“https://static.thenounproject.com/png/101791-200.png”)无重复权限; background-size: 20 px; ｝ <input type="text" class="icon-rtl" value placeholder="Search">

你可以试试这个:Bootstrap-4 Beta https://www.codeply.com/go/W25zyByhec

<div class="container">
            <form>
                <div class="row">
                    <div class="input-group mb-3 col-sm-6">
                      <input type="text" class="form-control border-right-0" placeholder="Username" aria-label="Username" aria-describedby="basic-addon1">
                        <div class="input-group-prepend bg-white">
                            <span class="input-group-text border-left-0 rounded-right bg-white" id="basic-addon1"><i class="fas fa-search"></i></span>
                        </div>
                    </div>
                </div>
            </form>
        </div>

与字体图标一起使用

<input name="foo" type="text" placeholder="&#61447;">

OR

<input id="foo" type="text" />

#foo::before
{
  font-family: 'FontAwesome';
  color:red;
  position: relative;
  left: -5px;
  content: "\f007";    
}

没有背景图片的解决方案:

.icon { padding-left: 25 px; 背景:url(“https://static.thenounproject.com/png/101791-200.png”)无重复左; background-size: 20 px; ｝ <input type="text" class="icon" value placeholder="Search">

或者从右到左的图标

.icon-rtl { padding-right: 25 px; 背景:url(“https://static.thenounproject.com/png/101791-200.png”)无重复权限; background-size: 20 px; ｝ <input type="text" class="icon-rtl" value placeholder="Search">

 <label for="fileEdit">
    <i class="fa fa-cloud-upload">
    </i>
    <input id="fileEdit" class="hidden" type="file" name="addImg" ng-file-change="onImageChange( $files )" ng-multiple="false" accept="{{ contentType }}"/>
  </label>

例如，你可以使用这个:标签隐藏输入(图标显示)。

这对我来说或多或少适用于标准表单:

  <button type="submit" value="Submit" name="ButtonType" id="whateveristheId" class="button-class">Submit<img src="/img/selectedImage.png" alt=""></button>