This article realizes the function of viewpager picture carousel, can smoothly switch pictures when sliding left and right, and there are no boundary restrictions.
1. Activity_main.xml layout
<RelativeLayout xmlns:andro xmlns:tools="/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <RelativeLayout android: android:layout_width="match_parent" android:layout_height="match_parent"/> </RelativeLayout>
Because my ViewPager inherits RelativeLayout
2. Layout in layout_recommend_item.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:andro android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <ImageView android: android:layout_width="match_parent" android:layout_height="match_parent" android:src="@mipmap/ic_launcher" android:layout_weight="1"/> <TextView android: android:text="123" android:layout_width="match_parent" android:layout_height="wrap_content" /> </LinearLayout>
ImageView is used to display the image TextView is used to display the title of each pager
3. MyViewPager class, because it is convenient to synthesize this function into a class, so it is more convenient to use it.
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public class MyViewPager extends RelativeLayout {
private static final int START_SCROLL = 1;
private static final int SCROLL_NEXT = 2;
private static final int SHOW_TIME = 5000;//Show time private List<String> mDatas = new ArrayList<>();//The title of each page of viewpager private ViewPager mPager;
private Context mContext;
private int mWidth, mHeight; //The width and height of viewpager private int mTitleHeight; //Title height private TipView mTipView; //The corresponding view of the title //Update the viewpager in the main ui, that is, switch pictures private static Handler sHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
int w = ;
ViewPager pager = (ViewPager) ;
switch (w) {
case START_SCROLL:
(msg.arg1, true);
break;
case SCROLL_NEXT:
(msg.arg1, true);
break;
}
}
};
/**
* Constructor
* @param context content
* @param w The width of the viewpager to be displayed
* @param h The height of the viewpager to be displayed
*/
public MyViewPager(Context context, int w, int h) {
super(context);
mContext = context;
mWidth = w;
mHeight = h;
initView(); //Get data. Just get it on the left just to look effective.// Listen to viewpager slide (new MOnPagerChangeListener());
init();
DisplayMetrics dm = ().getDisplayMetrics();
mTitleHeight = cm_DptoPx(48, dm);
}
/**
* Draw the width and height of the viewpager control
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
vp = getLayoutParams();
if (vp != null) {
= mWidth;
= mHeight;
}
(widthMeasureSpec, heightMeasureSpec);
}
/**
* Convert dp to px
*/
public static int cm_DptoPx(int dp,DisplayMetrics dis){
return (int) (TypedValue.COMPLEX_UNIT_DIP, dp, dis);
}
private void init() {
getData();
}
private void initView() {
mPager = new ViewPager(mContext);
rp = new (.MATCH_PARENT, .MATCH_PARENT);
addView(mPager, rp);
}
public void getData() {
for (int i = 0; i < 4 ; i++){
(i,"viewpager"+i);
}
(new Runnable() {
@Override
public void run() {
stopAnimation();
initTipView();
(new RecommendAdapter());
(10000 * ());
}
}, 2000);
}
/**
* Delete messages in the queue
*/
public void stopAnimation() {
(START_SCROLL);
(SCROLL_NEXT);
}
public void startAnimation() {
if (() == 0) {
return;
}
Message msg = (START_SCROLL);
= mPager;
msg.arg1 = (() + 1);//Get the next picture (msg, SHOW_TIME);//Send to the ui thread in 5 seconds }
/**
* Initialize the cursor to move the title view
*/
private void initTipView() {
if (mTipView == null) {
rp = new (10, 10);
(RelativeLayout.ALIGN_PARENT_BOTTOM);
= mTitleHeight;
mTipView = new TipView(mContext, ());
addView(mTipView, rp);
} else {
(());
}
}
private class MOnPagerChangeListener implements {
private int curState;
@Override
public void onPageScrolled(int i, float v, int i1) {
}
@Override
public void onPageSelected(int i) { //Sliding ends (SCROLL_NEXT);
(START_SCROLL);
if(curState == ViewPager.SCROLL_STATE_DRAGGING){
return;
}
Message msg = (SCROLL_NEXT);
msg.arg1 = i + 1;
= mPager;
(msg, SHOW_TIME);
(i % ());
}
@Override
public void onPageScrollStateChanged(int i) { //While sliding curState = i;
if(i == ViewPager.SCROLL_STATE_DRAGGING){ //SCROLL_STATE_DRAGGING is sliding SCROLL_STATE_IDLE does nothing //SCROLL_STATE_SETTLING Sliding completed stopAnimation();
}else {
if(!((START_SCROLL)&&(SCROLL_NEXT))){
startAnimation();
}
}
}
}
private class RecommendAdapter extends PagerAdapter {
@Override
public Object instantiateItem(ViewGroup container, int position) {
("MyViewPager","instantiateItem ");
int curPos = position % ();
View view = (mContext, .layout_recommend_item, null);
vp = new (.MATCH_PARENT, .MATCH_PARENT);
ImageView iv = (ImageView) (.iv_pic);
TextView tv = (TextView) (.tv_desc);
((curPos));
(view, vp);
(curPos);
(new OnClickListener() {
@Override
public void onClick(View v) {
}
});
return view;
}
@Override
public int getCount() {
return Integer.MAX_VALUE;
}
@Override
public boolean isViewFromObject(View view, Object o) {
return view == o;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((View) object);
}
}
private class TipView extends View {
private int mPadding;
private int mCount;
private int mCurPos;
private Paint mNorPaint;
private Paint mSelPaint;
private int mHeight;
public TipView(Context context, int count) {
super(context);
mNorPaint = new Paint();
(true);
DisplayMetrics dm = ().getDisplayMetrics();
int selHeight = cm_DptoPx(2, dm);
int norHeight = cm_DptoPx(1, dm);
mHeight = cm_DptoPx(2, dm);
(norHeight);
((80, 255, 255, 255));
mSelPaint = new Paint();
(true);
(selHeight);
();
mCount = count;
mPadding = cm_DptoPx(0, dm);
}
@Override
protected void onDraw(Canvas canvas) {
(canvas);
int ow = (getWidth()-2*mPadding)/ mCount;
int y = getHeight() / 2;
(mPadding, y, mCurPos * ow + mPadding, y, mNorPaint);
(mCurPos * ow + mPadding, y, (mCurPos + 1) * ow + mPadding, y, mSelPaint);
((mCurPos + 1) * ow + mPadding, y, getWidth() - mPadding, y, mNorPaint);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
vp = getLayoutParams();
= .MATCH_PARENT;
= mHeight;
(widthMeasureSpec, heightMeasureSpec);
}
public void setCurPostion(int pos) {
mCurPos = pos;
invalidate();
}
public void setCount(int count) {
mCount = count;
}
}
}
4. There are also implementations in MainActivity
import ;
import ;
import ;
import ;
public class MainActivity extends Activity {
private RelativeLayout mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
(savedInstanceState);
setContentView(.activity_main);
DisplayMetrics dm = getResources().getDisplayMetrics();
mViewPager = (RelativeLayout) findViewById(.my_viewpager);
(new MyViewPager(getApplicationContext(), ,()/2));
}
}
The above is all the content of this article. I hope it will be helpful to everyone's study and I hope everyone will support me more.