Android 圆角ListView

方法一：定义

<?xml version ="1.0" encoding ="UTF-8" ?>
<shape xmlns:android ="http://schemas.android.com/apk/res/android" android:shape ="rectangle" >
       <gradient android:startColor ="#B0BCCD" android:endColor ="#6D84A2" android:angle ="" />
       <corners android:bottomRightRadius ="8dp" android:bottomLeftRadius ="8dp" android:topLeftRadius ="8dp"
              android:topRightRadius ="8dp" />
</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 

public class RoundedRectListView extends ListView {
        private Context mContext;
        public RoundedRectListView( Context context) {
                super ( context) ;
                this .mContext = context;
                init( ) ;
        }
        public RoundedRectListView( Context context, AttributeSet attrs) {
                super ( context, attrs) ;
                this .mContext = context;
                init( ) ;
        }
        public RoundedRectListView( Context context, AttributeSet attrs, int defStyle) {
                super ( context, attrs, defStyle) ;
                this .mContext = context;
                init( ) ;
        }
        protected void init( ) {
                setBackgroundDrawable( mContext.getResources ( ) .getDrawable ( R.drawable .background_rounded_white ) ) ;
                setCacheColorHint( Color .WHITE ) ;
                setFooterDividersEnabled( false ) ;
        }
        @Override
        public boolean onInterceptTouchEvent( MotionEvent ev) { 

                switch ( ev.getAction ( ) ) {
                case MotionEvent.ACTION_DOWN :
                        int x = ( int ) ev.getX ( ) ;
                        int y = ( int ) ev.getY ( ) ;
                        int itemnum = pointToPosition( x, y) ;
                        if ( itemnum == AdapterView.INVALID_POSITION )
                                break ;
                        else
                        {
                                if ( itemnum== ) {
                                        if ( itemnum== ( getAdapter( ) .getCount ( ) - ) )
                                                setSelector( R.drawable .listview_selection_shade_rounded ) ;
                                        else
                                                setSelector( R.drawable .listview_selection_shade_top_rounded ) ;
                                }
                                else if ( itemnum== ( getAdapter( ) .getCount ( ) - ) )
                                        setSelector( R.drawable .listview_selection_shade_bottom_rounded ) ;
                                else
                                        setSelector( R.drawable .listview_selection_shade ) ;
                        }
                        break ;
                case MotionEvent.ACTION_UP :
                        break ;
                }
                return true ;
        }
}

方法三：定义selector

public class RoundedRectListView extends ListView {
        private Context mContext; 

        public RoundedRectListView( Context context) {
                super ( context) ;
                this .mContext = context;
                init( ) ;
        }
        public RoundedRectListView( Context context, AttributeSet attrs) {
                super ( context, attrs) ;
                this .mContext = context;
                init( ) ;
        }
        public RoundedRectListView( Context context, AttributeSet attrs, int defStyle) {
                super ( context, attrs, defStyle) ;
                this .mContext = context;
                init( ) ;
        }
        protected void init( ) {
                setBackgroundDrawable( mContext.getResources ( ) .getDrawable ( R.drawable .background_rounded_white ) ) ;
                setCacheColorHint( Color .WHITE ) ;
                setFooterDividersEnabled( false ) ;
        }
        @Override
        public boolean onInterceptTouchEvent( MotionEvent ev) { 

                switch ( ev.getAction ( ) ) {
                case MotionEvent.ACTION_DOWN :
                        int x = ( int ) ev.getX ( ) ;
                        int y = ( int ) ev.getY ( ) ;
                        int itemnum = pointToPosition( x, y) ; 

                        if ( itemnum == AdapterView.INVALID_POSITION )
                                break ;
                        else
                        {
                                if ( itemnum== ) {
                                        if ( itemnum== ( getAdapter( ) .getCount ( ) - ) )
                                                setSelector( R.drawable .listview_selection_shade_rounded ) ;
                                        else
                                                setSelector( R.drawable .listview_selection_shade_top_rounded ) ;
                                }
                                else if ( itemnum== ( getAdapter( ) .getCount ( ) - ) )
                                        setSelector( R.drawable .listview_selection_shade_bottom_rounded ) ;
                                else
                                        setSelector( R.drawable .listview_selection_shade ) ;
                        }
                        break ;
                case MotionEvent.ACTION_UP :
                        break ;
                }
                return true ;
        }
}

方法四：方法二和方法三的结合

public class RoundedRectListView extends ListView {   

        private Context mContext; 

        public RoundedRectListView( Context context) {
                super ( context) ;
                this .mContext = context;
                init( ) ;
        }
        public RoundedRectListView( Context context, AttributeSet attrs) {
                super ( context, attrs) ;
                this .mContext = context;
                init( ) ;
        }
        public RoundedRectListView( Context context, AttributeSet attrs, int defStyle) {
                super ( context, attrs, defStyle) ;
                this .mContext = context;
                init( ) ;
        }
       protected void init( ) {
                setBackgroundDrawable( mContext.getResources ( ) .getDrawable ( R.drawable .background_rounded_white ) ) ;
                setCacheColorHint( Color .WHITE ) ;
                setFooterDividersEnabled( false ) ;
                setSelector( new Selector( RoundedRectListView.this ,- ) ) ;
        }
   @Override
        public boolean onInterceptTouchEvent( MotionEvent ev) {
                switch ( ev.getAction ( ) ) {
                case MotionEvent.ACTION_DOWN :
                        int x = ( int ) ev.getX ( ) ;
                        int y = ( int ) ev.getY ( ) ;
                        int itemnum = pointToPosition( x, y) ;
                        if ( itemnum == AdapterView.INVALID_POSITION )
                                break ;
                        else
                        {
                           setSelector( new Selector( RoundedRectListView.this ,itemnum) ) ;
                        }
                        break ;
                case MotionEvent.ACTION_UP :
                        break ;
                }
                return true ;
        }
    class Selector extends Drawable {
        private static final String TAG = "Selector" ;
        private Paint mPaint;
        private AdapterView mList;
        private RectF mRectF;
        private int position; 

        public Selector( AdapterView list,int position) {
            mList = list;
            mPaint = new Paint ( ) ;
            mRectF = new RectF( ) ;
            this .position = position 

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

    mPaint.setShader ( g) ;
        }
        @Override
        public void draw( Canvas canvas) {
            Rect b = getBounds( ) ;
            int mPosition = mList.getSelectedItemPosition ( ) ;
            if ( mPosition==- ) {
                mPosition= position;
            }
            Log.d ( TAG, "Position :" + mPosition) ;
            canvas.save ( ) ;
            canvas.clipRect ( b.left , b.top , b.right , ( b.bottom + b.top ) / ) ;
            drawHalf( canvas, b, mPosition == ) ;
            canvas.restore ( ) ;
            canvas.save ( ) ;
            canvas.clipRect ( b.left , ( b.bottom + b.top ) / , b.right , b.bottom ) ;
            drawHalf( canvas, b, mPosition == mList.getAdapter ( ) .getCount ( ) -  && b.bottom == mList.getHeight ( ) ) ;
            canvas.restore ( ) ;
            Log.d ( TAG, "draw " + b) ;
        }
        private void drawHalf( Canvas canvas, Rect b ,boolean round) {           

            if ( round) {
                mRectF.set ( b) ;
                canvas.drawRoundRect ( mRectF, , , mPaint) ;
            } else {
                canvas.drawRect ( b, mPaint) ;
            }
        }
        @Override
        public int getOpacity( ) {
            return  ;
        }
        @Override
        public void setAlpha( int alpha) {
        }
        @Override
        public void setColorFilter( ColorFilter cf) {
        }
    }
}

方法五：

public class RoundedRectListView extends ListView {
    private static final float RADIUS =  ;
    private Path mClip;
    public RoundedRectListView( Context context, AttributeSet attrs) {
        super ( context, attrs) ;
        init( ) ;
    }
    private void init( ) {
        GradientDrawable gd = new GradientDrawable( ) ;
        gd.setCornerRadius ( RADIUS) ;
        gd.setColor ( 0xff208020) ;
        setBackgroundDrawable( gd) ;
        setCacheColorHint( ) ;
        setVerticalFadingEdgeEnabled( false ) ;
        StateListDrawable sld = new StateListDrawable( ) ;
        sld.addState (
                PRESSED_ENABLED_STATE_SET,
                new GradientDrawable( Orientation.LEFT_RIGHT , new int [ ] { 0xffa58cf5, 0xffa13f99} ) ) ;
        sld.addState (
                EMPTY_STATE_SET,
                new GradientDrawable( Orientation.LEFT_RIGHT , new int [ ] { 0xff058cf5, 0xff013f99} ) ) ;
        setSelector( sld) ;
    }
    @Override
    protected void onSizeChanged( int w, int h, int oldw, int oldh) {
        super .onSizeChanged ( w, h, oldw, oldh) ;
        mClip = new Path( ) ;
        RectF rect = new RectF( , , w, h) ;
        mClip.addRoundRect ( rect, RADIUS, RADIUS, Direction.CW ) ;
    }
   @Override
    protected void dispatchDraw( Canvas canvas) {
        canvas.save ( ) ;
        canvas.clipPath ( mClip) ;
        super .dispatchDraw ( canvas) ;
        canvas.restore ( ) ;
    }
}

第五种方法最好