android ListView实现圆角

方法一：定义

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1	<?xml version ="1.0" encoding ="UTF-8" ?>

2	<shape xmlns:android ="http://schemas.android.com/apk/res/android" android:shape ="rectangle" >

3	<gradient android:startColor ="#B0BCCD" android:endColor ="#6D84A2" android:angle ="270" />

4	<corners android:bottomRightRadius ="8dp" android:bottomLeftRadius ="8dp" android:topLeftRadius ="8dp"

5	android:topRightRadius ="8dp" />

6

7

</shape>

布局文件中的ListView属性android:listSelector="@drawable/shape"

存在问题是，ListView最上面或者最下面的item选中时，圆角背景变成直角的

方法二：修改选中item 

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01	public class RoundedRectListView extends ListView {

02	private Context mContext;

03	public RoundedRectListView( Context context) {

04	super ( context) ;

05	this .mContext = context;

06

init( ) ;

07

}

08	public RoundedRectListView( Context context, AttributeSet attrs) {

09	super ( context, attrs) ;

10	this .mContext = context;

11

init( ) ;

12

}

13	public RoundedRectListView( Context context, AttributeSet attrs, int defStyle) {

14	super ( context, attrs, defStyle) ;

15	this .mContext = context;

16

init( ) ;

17

}

18	protected void init( ) {

19	setBackgroundDrawable( mContext.getResources ( ) .getDrawable ( R.drawable .background_rounded_white ) ) ;

20	setCacheColorHint( Color .WHITE ) ;

21	setFooterDividersEnabled( false ) ;

22

}

23

@Override

24	public boolean onInterceptTouchEvent( MotionEvent ev) {

25

26	switch ( ev.getAction ( ) ) {

27	case MotionEvent.ACTION_DOWN :

28	int x = ( int ) ev.getX ( ) ;

29	int y = ( int ) ev.getY ( ) ;

30	int itemnum = pointToPosition( x, y) ;

31	if ( itemnum == AdapterView.INVALID_POSITION )

32

break ;

33

else

34

{

35	if ( itemnum== 0) {

36	if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )

37	setSelector( R.drawable .listview_selection_shade_rounded ) ;

38

else

39	setSelector( R.drawable .listview_selection_shade_top_rounded ) ;

40

}

41	else if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )

42	setSelector( R.drawable .listview_selection_shade_bottom_rounded ) ;

43

else

44	setSelector( R.drawable .listview_selection_shade ) ;

45

}

46

break ;

47	case MotionEvent.ACTION_UP :

48

break ;

49

}

50	return true ;

51

}

52

}

方法三：定义selector

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01	public class RoundedRectListView extends ListView {

02	private Context mContext;

03

04	public RoundedRectListView( Context context) {

05	super ( context) ;

06	this .mContext = context;

07

init( ) ;

08

}

09	public RoundedRectListView( Context context, AttributeSet attrs) {

10	super ( context, attrs) ;

11	this .mContext = context;

12

init( ) ;

13

}

14	public RoundedRectListView( Context context, AttributeSet attrs, int defStyle) {

15	super ( context, attrs, defStyle) ;

16	this .mContext = context;

17

init( ) ;

18

}

19	protected void init( ) {

20	setBackgroundDrawable( mContext.getResources ( ) .getDrawable ( R.drawable .background_rounded_white ) ) ;

21	setCacheColorHint( Color .WHITE ) ;

22	setFooterDividersEnabled( false ) ;

23

}

24

@Override

25	public boolean onInterceptTouchEvent( MotionEvent ev) {

26

27	switch ( ev.getAction ( ) ) {

28	case MotionEvent.ACTION_DOWN :

29	int x = ( int ) ev.getX ( ) ;

30	int y = ( int ) ev.getY ( ) ;

31	int itemnum = pointToPosition( x, y) ;

32

33	if ( itemnum == AdapterView.INVALID_POSITION )

34

break ;

35

else

36

{

37	if ( itemnum== 0) {

38	if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )

39	setSelector( R.drawable .listview_selection_shade_rounded ) ;

40

else

41	setSelector( R.drawable .listview_selection_shade_top_rounded ) ;

42

}

43	else if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )

44	setSelector( R.drawable .listview_selection_shade_bottom_rounded ) ;

45

else

46	setSelector( R.drawable .listview_selection_shade ) ;

47

}

48

break ;

49	case MotionEvent.ACTION_UP :

50

break ;

51

}

52	return true ;

53

}

54

}

方法四：方法二和方法三的结合

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001	public class RoundedRectListView extends ListView {

002

003	private Context mContext;

004

005	public RoundedRectListView( Context context) {

006	super ( context) ;

007	this .mContext = context;

008

init( ) ;

009

}

010	public RoundedRectListView( Context context, AttributeSet attrs) {

011	super ( context, attrs) ;

012	this .mContext = context;

013

init( ) ;

014

}

015	public RoundedRectListView( Context context, AttributeSet attrs, int defStyle) {

016	super ( context, attrs, defStyle) ;

017	this .mContext = context;

018

init( ) ;

019

}

020	protected void init( ) {

021	setBackgroundDrawable( mContext.getResources ( ) .getDrawable ( R.drawable .background_rounded_white ) ) ;

022	setCacheColorHint( Color .WHITE ) ;

023	setFooterDividersEnabled( false ) ;

024	setSelector( new Selector( RoundedRectListView.this ,- 1) ) ;

025

}

026

@Override

027	public boolean onInterceptTouchEvent( MotionEvent ev) {

028	switch ( ev.getAction ( ) ) {

029	case MotionEvent.ACTION_DOWN :

030	int x = ( int ) ev.getX ( ) ;

031	int y = ( int ) ev.getY ( ) ;

032	int itemnum = pointToPosition( x, y) ;

033	if ( itemnum == AdapterView.INVALID_POSITION )

034

break ;

035

else

036

{

037	setSelector( new Selector( RoundedRectListView.this ,itemnum) ) ;

038

}

039

break ;

040	case MotionEvent.ACTION_UP :

041

break ;

042

}

043	return true ;

044

}

045	class Selector extends Drawable {

046	private static final String TAG = "Selector" ;

047	private Paint mPaint;

048	private AdapterView mList;

049	private RectF mRectF;

050	private int position;

051

052	public Selector( AdapterView list,int position) {

053	mList = list;

054	mPaint = new Paint ( ) ;

055	mRectF = new RectF( ) ;

056	this .position = position

057

058	LinearGradient g= new LinearGradient( mRectF.top ,mRectF.left ,mRectF.right ,mRectF.bottom ,Color .parseColor ( "#058cf5" ) ,Color .parseColor ( "#015fe6" ) ,TileMode.REPEAT ) ;

059

060	mPaint.setShader ( g) ;

061

}

062

@Override

063	public void draw( Canvas canvas) {

064	Rect b = getBounds( ) ;

065	int mPosition = mList.getSelectedItemPosition ( ) ;

066	if ( mPosition==- 1) {

067	mPosition= position;

068

}

069	Log.d ( TAG, "Position :" + mPosition) ;

070	canvas.save ( ) ;

071	canvas.clipRect ( b.left , b.top , b.right , ( b.bottom + b.top ) / 2) ;

072	drawHalf( canvas, b, mPosition == 0) ;

073	canvas.restore ( ) ;

074	canvas.save ( ) ;

075	canvas.clipRect ( b.left , ( b.bottom + b.top ) / 2, b.right , b.bottom ) ;

076	drawHalf( canvas, b, mPosition == mList.getAdapter ( ) .getCount ( ) - 1 && b.bottom == mList.getHeight ( ) ) ;

077	canvas.restore ( ) ;

078	Log.d ( TAG, "draw " + b) ;

079

}

080	private void drawHalf( Canvas canvas, Rect b ,boolean round) {

081

082	if ( round) {

083	mRectF.set ( b) ;

084	canvas.drawRoundRect ( mRectF, 10, 10, mPaint) ;

085

} else {

086	canvas.drawRect ( b, mPaint) ;

087

}

088

}

089

@Override

090	public int getOpacity( ) {

091	return 0 ;

092

}

093

@Override

094	public void setAlpha( int alpha) {

095

}

096

@Override

097	public void setColorFilter( ColorFilter cf) {

098

}

099

}

100

}

方法五：

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01	public class RoundedRectListView extends ListView {

02	private static final float RADIUS = 16 ;

03	private Path mClip;

04	public RoundedRectListView( Context context, AttributeSet attrs) {

05	super ( context, attrs) ;

06

init( ) ;

07

}

08	private void init( ) {

09	GradientDrawable gd = new GradientDrawable( ) ;

10	gd.setCornerRadius ( RADIUS) ;

11	gd.setColor ( 0xff208020) ;

12	setBackgroundDrawable( gd) ;

13	setCacheColorHint( 0) ;

14	setVerticalFadingEdgeEnabled( false ) ;

15	StateListDrawable sld = new StateListDrawable( ) ;

16	sld.addState (

17	PRESSED_ENABLED_STATE_SET,

18	new GradientDrawable( Orientation.LEFT_RIGHT , new int [ ] { 0xffa58cf5, 0xffa13f99} ) ) ;

19	sld.addState (

20	EMPTY_STATE_SET,

21	new GradientDrawable( Orientation.LEFT_RIGHT , new int [ ] { 0xff058cf5, 0xff013f99} ) ) ;

22	setSelector( sld) ;

23

}

24

@Override

25	protected void onSizeChanged( int w, int h, int oldw, int oldh) {

26	super .onSizeChanged ( w, h, oldw, oldh) ;

27	mClip = new Path( ) ;

28	RectF rect = new RectF( 0, 0, w, h) ;

29	mClip.addRoundRect ( rect, RADIUS, RADIUS, Direction.CW ) ;

30

}

31

@Override

32	protected void dispatchDraw( Canvas canvas) {

33	canvas.save ( ) ;

34	canvas.clipPath ( mClip) ;

35	super .dispatchDraw ( canvas) ;

36	canvas.restore ( ) ;

37

}

38

}

第五种方法最好