Android自定义组件

最新推荐文章于 2024-05-06 08:56:50 发布

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本文介绍了在Android中创建自定义View组件所需重写的关键方法。包括构造函数、布局、绘制及事件处理等环节，并详细说明了每个方法的作用。

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http://developer.android.com/guide/topics/ui/custom-components.html

下面的表格给出了实现一个具体View要重写的方法。

Creation	Constructors	There is a form of the constructor that are called when the view is created from code and a form that is called when the view is inflated from a layout file. The second form should parse and apply any attributes defined in the layout file.
`onFinishInflate()`	Called after a view and all of its children has been inflated from XML.
Layout	`onMeasure(int, int)`	Called to determine the size requirements for this view and all of its children.
`onLayout(boolean, int, int, int, int)`	Called when this view should assign a size and position to all of its children.
`onSizeChanged(int, int, int, int)`	Called when the size of this view has changed.
Drawing	`onDraw(Canvas)`	Called when the view should render its content.
Event processing	`onKeyDown(int, KeyEvent)`	Called when a new key event occurs.
`onKeyUp(int, KeyEvent)`	Called when a key up event occurs.
`onTrackballEvent(MotionEvent)`	Called when a trackball motion event occurs.
`onTouchEvent(MotionEvent)`	Called when a touch screen motion event occurs.
Focus	`onFocusChanged(boolean, int, Rect)`	Called when the view gains or loses focus.
`onWindowFocusChanged(boolean)`	Called when the window containing the view gains or loses focus.
Attaching	`onAttachedToWindow()`	Called when the view is attached to a window.
`onDetachedFromWindow()`	Called when the view is detached from its window.
`onWindowVisibilityChanged(int)`	Called when the visibility of the window containing the view has changed.