31 lines
		
	
	
		
			992 B
		
	
	
	
		
			Markdown
		
	
	
			
		
		
	
	
			31 lines
		
	
	
		
			992 B
		
	
	
	
		
			Markdown
		
	
	
| ---
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| category: Components
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| type: Other
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| title: BackTop
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| cover: https://gw.alipayobjects.com/zos/alicdn/tJZ5jbTwX/BackTop.svg
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| ---
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| 
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| `BackTop` makes it easy to go back to the top of the page.
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| 
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| ## When To Use
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| 
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| - When the page content is very long.
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| - When you need to go back to the top very frequently in order to view the contents.
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| 
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| ## API
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| 
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| > The distance to the bottom is set to `50px` by default, which is overridable.
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| >
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| > If you decide to use custom styles, please note the size limit: no more than `40px * 40px`.
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| 
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| | Property | Description | Type | Default | Version |
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| | --- | --- | --- | --- | --- |
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| | target | specifies the scrollable area dom node | () => HTMLElement | () => window |  |
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| | visibilityHeight | the `BackTop` button will not show until the scroll height reaches this value | number | 400 |  |
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| 
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| ### events
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| 
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| | Events Name | Description | Arguments | Version |
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| | --- | --- | --- | --- |
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| | click | a callback function, which can be executed when you click the button | Function |  |
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