Android 实现圆角ListView 几种方法

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 ="270" />
<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== 0) {
if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )
setSelector( R.drawable .listview_selection_shade_rounded ) ;
else
setSelector( R.drawable .listview_selection_shade_top_rounded ) ;
}
else if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )
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== 0) {
if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )
setSelector( R.drawable .listview_selection_shade_rounded ) ;
else
setSelector( R.drawable .listview_selection_shade_top_rounded ) ;
}
else if ( itemnum== ( getAdapter( ) .getCount ( ) - 1) )
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 ,- 1) ) ;
}
@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==- 1) {
mPosition= position;
}
Log.d ( TAG, "Position :" + mPosition) ;
canvas.save ( ) ;
canvas.clipRect ( b.left , b.top , b.right , ( b.bottom + b.top ) / 2) ;
drawHalf( canvas, b, mPosition == 0) ;
canvas.restore ( ) ;
canvas.save ( ) ;
canvas.clipRect ( b.left , ( b.bottom + b.top ) / 2, b.right , b.bottom ) ;
drawHalf( canvas, b, mPosition == mList.getAdapter ( ) .getCount ( ) - 1 && 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, 10, 10, mPaint) ;
} else {
canvas.drawRect ( b, mPaint) ;
}
}
@Override
public int getOpacity( ) {
return 0 ;
}
@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 = 16 ;
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( 0) ;
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( 0, 0, 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 ( ) ;
}
}