在android移動端的開發中,首頁輪播圖是一個特別常見的功能,所以今天就來將最近寫的一個小demo記錄一下。
首先當然是新建一個項目代碼如下:
activity_main.xml文件:
<?xml version="1.0" encoding="utf-8"?><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.yzp.viewpagedemo.MainActivity" android:background="#f6f6f6"> <!--輪播圖--> <RelativeLayout android:id="@+id/topPanel_vpg" android:layout_width="match_parent" android:layout_height="190dp" > <android.support.v4.view.ViewPager android:id="@+id/ViewPage_Detail" android:layout_width="wrap_content" android:layout_height="wrap_content" android:flipInterval="30" android:persistentDrawingCache="animation" /> <LinearLayout android:id="@+id/point_detail" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:orientation="horizontal" android:layout_centerHorizontal="true" android:layout_alignParentBottom="true" > </LinearLayout> </RelativeLayout></RelativeLayout>
MainActivity
package com.yzp.viewpagedemo;import android.content.Context;import android.os.Handler;import android.os.Message;import android.support.v4.view.ViewPager;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.ImageView;import android.widget.LinearLayout;import java.util.ArrayList;public class MainActivity extends AppCompatActivity { private ViewPager ViewPage_Detail; private LinearLayout point_detail; private Context context; private View view; //輪播圖圖片資源 private final int[] viewpage_images = {R.mipmap.two, R.mipmap.three, R.mipmap.four, R.mipmap.fifve}; private ArrayList<ImageView> viewpage_imageList; //判斷是否自動滾動ViewPage private boolean isRunning = true; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Instantiation(); } public void Instantiation() { ViewPage_Detail = (ViewPager)findViewById(R.id.ViewPage_Detail); point_detail = (LinearLayout)findViewById(R.id.point_detail); //初始化圖片資源 viewpage_imageList = new ArrayList<ImageView>(); for (int i : viewpage_images) { // 初始化圖片資源 ImageView imageView = new ImageView(this); imageView.setBackgroundResource(i); viewpage_imageList.add(imageView); // 添加指示小點 ImageView point = new ImageView(this); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(15, 15); params.rightMargin = 10; params.bottomMargin = 15; point.setLayoutParams(params); point.setBackgroundResource(R.mipmap.light_blue_point); if (i == R.mipmap.two) { //默認聚焦在第一張 point.setBackgroundResource(R.mipmap.blue_point); point.setEnabled(true); } else { point.setEnabled(false); } point_detail.addView(point); } //首頁輪播 CarouselShow carouselShow = new CarouselShow(context, viewpage_imageList); carouselShow.CarouselShow_Info_Detail(this); handler.sendEmptyMessageDelayed(0, 3000); } private Handler handler = new Handler() { public void handleMessage(Message msg) { // 執行滑動到下一個頁面 ViewPage_Detail.setCurrentItem(ViewPage_Detail.getCurrentItem() + 1); if (isRunning) { // 在發一個handler延時 handler.sendEmptyMessageDelayed(0, 3000); } } }; @Override public void onDestroy() { // 停止滾動 isRunning = false; super.onDestroy(); }}CarouselShow類(輪播功能實現):
package com.yzp.viewpagedemo;import android.content.Context;import android.support.v4.view.ViewPager;import android.widget.ImageView;import android.widget.LinearLayout;import java.util.ArrayList;/** * 輪播展示公共類 * 作者: yzp on 2016-09-07. * E-mail: 15111424807@163.com * QQ: 486492302 */public class CarouselShow { private final Context context; private LinearLayout point_group; private ArrayList<ImageView> viewpage_imageList; protected int lastPosition = 0; private ViewPager ViewPage_Detail; private LinearLayout point_detail; public CarouselShow(Context context, ArrayList<ImageView> viewpage_imageList) { this.context = context; this.viewpage_imageList = viewpage_imageList; } /** * 當需要多個輪播功能的時候 建立一個類來調用 并實現此方法 */ public void CarouselShow_Info_Detail(MainActivity view){ ViewPage_Detail = (ViewPager)view.findViewById(R.id.ViewPage_Detail); point_detail = (LinearLayout) view.findViewById(R.id.point_detail); ViewPage_Detail.setAdapter(new TeaNetPageAdapter(viewpage_imageList)); // 設置當前viewPager的位置 ViewPage_Detail.setCurrentItem(Integer.MAX_VALUE / 2 - (Integer.MAX_VALUE / 2 % viewpage_imageList.size())); ViewPage_Detail.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageSelected(int position) { // 頁面切換后調用, position是新的頁面位置 // 實現無限制循環播放 position %= viewpage_imageList.size(); // 把當前點設置為true,將上一個點設為false;并設置point_group圖標 point_detail.getChildAt(position).setEnabled(true); point_detail.getChildAt(position).setBackgroundResource(R.mipmap.blue_point);//設置聚焦時的圖標樣式 point_detail.getChildAt(lastPosition).setEnabled(false); point_detail.getChildAt(lastPosition).setBackgroundResource(R.mipmap.light_blue_point);//上一張恢復原有圖標 lastPosition = position; } @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageScrollStateChanged(int state) { } }); }}TeaNetPageAdapter(適配器):
package com.yzp.viewpagedemo;import android.support.v4.view.PagerAdapter;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import java.util.ArrayList;/** * 作者: yzp on 2016-09-07. * E-mail: 15111424807@163.com * QQ: 486492302 */public class TeaNetPageAdapter extends PagerAdapter { private ArrayList<ImageView> viewpage_imageList; public TeaNetPageAdapter(ArrayList<ImageView> viewpage_imageList) { this.viewpage_imageList = viewpage_imageList; } // 需要實現以下四個方法 @Override public int getCount() { return Integer.MAX_VALUE; } @Override public boolean isViewFromObject(View view, Object object) { // 判斷view和Object對應是否有關聯關系 if (view == object) { return true; } else { return false; } } @Override public Object instantiateItem(ViewGroup container, int position) { // 獲得相應位置上的view; container view的容器,其實就是viewpage自身, // position: viewpager上的位置 // 給container添加內容 container.addView(viewpage_imageList.get(position % viewpage_imageList.size())); return viewpage_imageList.get(position % viewpage_imageList.size()); } @Override public void destroyItem(ViewGroup container, int position, Object object) { // 銷毀對應位置上的Object // super.destroyItem(container, position, object); container.removeView((View) object); object = null; }}簡單的幾個類,首頁輪播的功能就實現了,不過主類的圖片資源就沒有貼出來了,到時候可以自己下載幾張圖片,貼到mipmap文件夾下就OK了。
效果圖展示:

以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持VEVB武林網。
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