Views in Android

Views

ScrollView滚动到顶部

• scrollTo(0, 0)

可以使用tyicoe

View的属性

• descendantFocusability

View的绘制过程

     B: *      1. Draw the background
     S：*      2. If necessary, save the canvas' layers to prepare for fading
     C：*      3. Draw view's content //onDraw
     C：*      4. Draw children//dispatchDraw
     R：*      5. If necessary, draw the fading edges and restore layers
     D：*      6. Draw decorations (scrollbars for instance)

• parent.draw
• parent.onDraw
• parent.dispatchDraw
• child.dispatchDraw

Canvas总结

View的measure过程

• measure(widthSpec, heightSpec)
• onMeasure
• Measure的mode
• AT_MOST
• EXACTLY
• UNSPECIFIED
• 通过MeasureSpec.getMode获得

View的layout过程

• generateLayoutParams
• checkLayoutParams

横竖屏切换View的改变

• 有这句话：android:configChanges="orientation|screenSize|keyboardHidden"，横竖屏切换不会重新调用生命周期

自定义View

• 自定义ViewGroup http://lucasr.org/2014/05/12/custom-layouts-on-android/

TransformationInfo