Android自動無限輪播圖viewpager的使用
阿新 • • 發佈:2019-02-11
1、具體步驟
說下大概實現步驟,一般我們有兩種,一種是viewpager+作為遊標的點 。另外一種是重寫viewpager。
效果圖:
1.1 佈局,直接viewpager+一個viewgroup就好。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.maxence.viewpager.MainActivity" > <RelativeLayout android:layout_width="match_parent" android:layout_height="220dp" > <android.support.v4.view.ViewPager android:id="@+id/vp_pager" android:layout_width="match_parent" android:layout_height="match_parent" /> <!-- 作為viewgroup 動態 add 遊標 --> <LinearLayout android:id="@+id/ll_container" android:layout_width="match_parent" android:layout_height="30dp" android:gravity="center" android:orientation="horizontal" android:layout_alignParentBottom="true" ></LinearLayout> </RelativeLayout> </RelativeLayout>
1.2 動態add的點,常規白點:point_normal.xml。
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <stroke android:width="1dip" android:color="#ffffff"/> <solid android:color="#ffffff" /> </shape>
選中為紅點: point_select.xml
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <stroke android:width="1dp" android:color="#ff0000" /> <solid android:color="#ff0000"/> </shape>
1.3動態新增進去圖片和遊標點。
/**
* 初始化資料
*/
private void initData() {
mContext = this;
int[] i = new int[] { R.drawable.bg_lunbo1, R.drawable.bg_lunbo2, R.drawable.bg_lunbo3, R.drawable.bg_lunbo4 };
al = new ArrayList<ImageView>();
for (int x = 0; x < i.length; x++) {
ImageView iv = new ImageView(mContext);
iv.setBackgroundResource(i[x]);
al.add(iv);
View v=new View(mContext);
v.setBackgroundResource(R.drawable.point_normal);
//有多少張圖就放置幾個點
LayoutParams layoutParams = new LinearLayout.LayoutParams(15, 15);
layoutParams.leftMargin = 30;
ll_container.addView(v,layoutParams);
}
vp_pager.setAdapter(new Myadapter());
vp_pager.setOnPageChangeListener(this);
vp_pager.setCurrentItem(al.size()*1000); //這個是無線輪詢的關鍵
ll_container.getChildAt(0).setBackgroundResource(R.drawable.point_select);
prePosition=0;
}
1.4 viewpgaer繫結PagerAdapter,這樣就能滑動照片並且無限滑了。
class Myadapter extends PagerAdapter {
@Override
public int getCount() {
return Integer.MAX_VALUE; // 要無限輪播
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
int position1=position % al.size();
ImageView imageView = al.get(position1);
container.addView(imageView);
return imageView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View)object);
}
}
1.5 實現遊標,就是滑動圖片,下面的紅點也跟著變化。
vp_pager.setOnPageChangeListener(this);
@Override
public void onPageScrollStateChanged(int arg0) {
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageSelected(int position) {
int newPosition = position % al.size();
ll_container.getChildAt(newPosition).setBackgroundResource(R.drawable.point_select);
ll_container.getChildAt(prePosition).setBackgroundResource(R.drawable.point_normal);
prePosition=newPosition;
}
1.6實現自動輪詢。開啟一個執行緒即可。
/**
* 自動輪詢
*/
private void pollint() {
pThread = new PollThread();
pThread.start();
}
class PollThread extends Thread{
@Override
public void run() {
while (poll){
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
runOnUiThread(new Runnable() {
@Override
public void run() {
vp_pager.setCurrentItem(vp_pager.getCurrentItem()+1);
}
});
}
}
}
這樣就搞定了,僅僅提供一個思路。自己可以擴充套件,例如重寫viewpager,把功能封裝在內部即可。