same
rgba和opacity都是CSS中常用的透明处理属性
the difference:
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The range of values is different: rgba is used to set a color, and its transparency can be specified, while opacity can only specify the overall transparency of all content (including text, pictures, etc.). The value range of rgba is 0-255, which represents the color value of the three color channels of red, green, and blue and a transparency channel; while the value range of opacity is 0-1, where 0 means completely transparent and 1 means completely opaque.
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The transparency calculation method is different: when the browser renders, when the element uses rgba to set the transparency, the calculation method is achieved by mixing the element with the background color below it, which means that the transparency of the element can also affect the underlying elements. The opacity attribute acts directly on the entire element, making all content inside the element more transparent.
In addition, it is also important to note that:
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Compatibility issues between rgba and opacity: opacity is an attribute in the CSS2 specification, and it has good compatibility with all browsers that support CSS2, while rgba is an attribute in CSS3, which may appear in some old browsers If there is a compatibility problem, some additional compatibility processing is required.
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Different application scenarios: Since rgba can more precisely control the transparency of elements, it is more suitable for dealing with color backgrounds that require different transparency. And opacity is more suitable for dealing with situations where transparency is required for all content, such as modal boxes, filter effects, etc.
In short, both rgba and opacity are common attributes to achieve transparency effects, and the specific usage depends on specific design requirements and application scenarios.