div 和 span 中的 CSS 类 IMG
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CSS class IMG inside div and span
提问by Pawe? Domański
Hi on beginning I have code like this:
嗨，一开始我有这样的代码：
<div class="123_test" tabindex="0" role="button">
<span class="">
<img class="" alt="" src="picturetopic"></img>
</span>
</div>
How can I style this imgwith 123_testclass?
我怎样才能img用123_test班级来设计这个？
回答by Mr. Alien
First of all you cannot start a class name using a digit, I assume that it's generating from somewhere as the classes are empty, but if you can, than consider changing it, like
首先，您不能使用数字开头的类名，我假设它是从某个地方生成的，因为类是空的，但是如果可以，请考虑更改它，例如
class="name_123_test"
And use the selector below like
并使用下面的选择器
.name_123_test > span img {
/* Styles goes here */
}
In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, two hyphens, or a hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code (see next item). For instance, the identifier "B&W?" may be written as "B\&W\?" or "B\26 W\3F".
在 CSS 中，标识符（包括选择器中的元素名称、类和 ID）只能包含字符 [a-zA-Z0-9] 和 ISO 10646 字符 U+00A0 及更高，加上连字符 (-) 和下划线 ( _); 它们不能以一个数字、两个连字符或一个连字符后跟一个数字开头。标识符还可以包含转义字符和任何 ISO 10646 字符作为数字代码（参见下一项）。例如，标识符“B&W？” 可以写成“B\&W\?” 或“B\26 W\3F”。
回答by David
Why are your classattributes empty?
为什么你的class属性是空的？
If you want to apply the 123_testclass to the imgtag, just add it in the classattribute:
如果要将123_test类应用于img标签，只需将其添加到class属性中：
<img class="123_test" alt="" src="picturetopic"></img>
Or do you mean that you want to use the ancestor divas a style guide for the img? In your CSS, you can reference the imgas a descendant of the 123_testclass:
或者你的意思是你想使用祖先div作为 的风格指南img？在您的 CSS 中，您可以将 引用img为123_test类的后代：
.123_test img
{
// css rules
}
The space between the two identifiers means that the latter is a descendant of the former.
两个标识符之间的空格表示后者是前者的后代。
回答by roemel
You can't name a class beginning with a numer. So change your class name to class="test_123"or something that does not begin with a number.
你不能命名一个以数字开头的类。因此，将您的班级名称更改为class="test_123"不以数字开头的名称。
And now you can style your img in this way:
现在你可以用这种方式设置你的 img 样式：
.test_123 // here you put your class name after the "."
{
// style your image here
}
回答by Roralee
In addition, use better HTML markup for the functionality:
此外，为功能使用更好的 HTML 标记：
<button type="button" class="test_123" tabindex="0">
<span>
<img alt="" src="picturetopic" />
</span>
</button>
Buttons of type="button" can contain text or an image. If the image contains text, it would be better to use css to create the graphical effect for compliance w/ accessibility guidelines and display across multiple devices.
type="button" 的按钮可以包含文本或图像。如果图像包含文本，最好使用 css 来创建符合可访问性指南的图形效果并在多个设备上显示。
