Android 图片自动切换

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Android 图片自动切换

效果图：

效果图

思路：利用 android.support.v4.view.ViewPager 和线程实现图片切换。
1. 首先把图片放入分别放入不同的 ImageView
2.然后重写一下 ViewPager 的适配器 PagerAdapter
3.然后重写一个实现更新界面等操作
4：在onStart里面切换图片

配置文件代码如下：

<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" >    <FrameLayout        android:layout_width="fill_parent"        android:layout_height="200dip"        >        <android.support.v4.view.ViewPager            android:id="@+id/vp"            android:layout_width="match_parent"            android:layout_height="match_parent"            />        <LinearLayout            android:layout_width="match_parent"            android:layout_height="35dip"            android:orientation="vertical"            android:layout_gravity="bottom"            android:gravity="center"            android:background="#33000000"            >            <TextView                android:id="@+id/tv_test_title"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="图片标题"                android:textColor="@android:color/white"                />            <LinearLayout                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:orientation="horizontal"                android:layout_marginTop="3dip"                >                <View                    android:id="@+id/dot_0"                    android:layout_width="5dip"                    android:layout_height="5dip"                    android:layout_marginLeft="2dip"                    android:layout_marginRight="2dip"                    android:background="@drawable/background"                    />                <View                    android:id="@+id/dot_1"                    android:layout_width="5dip"                    android:layout_height="5dip"                    android:layout_marginLeft="2dip"                    android:layout_marginRight="2dip"                    android:background="@drawable/background1"                    />                <View                    android:id="@+id/dot_2"                    android:layout_width="5dip"                    android:layout_height="5dip"                    android:layout_marginLeft="2dip"                    android:layout_marginRight="2dip"                    android:background="@drawable/background2"                    />                <View                    android:id="@+id/dot_3"                    android:layout_width="5dip"                    android:layout_height="5dip"                    android:layout_marginLeft="2dip"                    android:layout_marginRight="2dip"                    android:background="@drawable/background3"                    />                <View                    android:id="@+id/dot_4"                    android:layout_width="5dip"                    android:layout_height="5dip"                    android:layout_marginLeft="2dip"                    android:layout_marginRight="2dip"                    android:background="@drawable/background4"                    />            </LinearLayout>        </LinearLayout>    </FrameLayout></RelativeLayout>

java 文件为：

package androidstudio.android_test_ck;import android.os.Handler;import android.os.Message;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;import java.util.ArrayList;import java.util.concurrent.Executors;import java.util.concurrent.ScheduledExecutorService;import java.util.concurrent.TimeUnit;public class MainTestActivity extends AppCompatActivity {    private int imageIds[] = {R.drawable.background, R.drawable.background1, R.drawable.background2, R.drawable.background3, R.drawable.background4};    private ArrayList<ImageView> images = new ArrayList<>();    private ViewPager vp;    private int oldPosition = 0;//记录上一次点的位置    private int currentItem; //当前页面    private ScheduledExecutorService scheduledExecutorService;    //图片标题    private String titles[] = new String[]{"图片1", "图片2", "图片3", "图片4", "图片5"};    private ArrayList<View> dots = new ArrayList<View>();;    private TextView title;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main_test);        for (int i = 0; i < imageIds.length; i++) {            ImageView imageView = new ImageView(this);            imageView.setImageResource(imageIds[i]);            images.add(imageView);        }        //显示的点 加入集合        dots.add(findViewById(R.id.dot_0));        dots.add(findViewById(R.id.dot_1));        dots.add(findViewById(R.id.dot_2));        dots.add(findViewById(R.id.dot_3));        dots.add(findViewById(R.id.dot_4));        //获取图片标题的id        title = (TextView) findViewById(R.id.tv_test_title);         //获取ViewPager 的id        vp = (ViewPager) findViewById(R.id.vp);        vp.setAdapter(new ViewPagerAdapter());        vp.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {            }            @Override            public void onPageSelected(int position) {            //设置页面刷新后的图片标题                title.setText(titles[position]);                oldPosition = position;                currentItem = position;            }            @Override            public void onPageScrollStateChanged(int state) {            }        });    }    class ViewPagerAdapter extends PagerAdapter{        @Override        public int getCount() {            return images.size();        }        @Override        public boolean isViewFromObject(View view, Object object) {            return view==object;        }        @Override        public void destroyItem(ViewGroup container, int position, Object object) {        //将试图移除试图组            View v =images.get(position);            container.removeView(v);        }        @Override        public Object instantiateItem(ViewGroup container, int position) {            //将试图添加进试图组            View v =images.get(position);            container.addView(v);            return v;        }    }    @Override    protected void onStart() {        super.onStart();        scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();        //每隔两秒换一张图片        scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(),2,2, TimeUnit.SECONDS);    }    //实现一个碎片的接口    class ViewPagerTask implements Runnable{        @Override        public void run() {            currentItem = (currentItem+1)%imageIds.length;            //更新界面            handler.obtainMessage().sendToTarget();        }    }    //在handler进行碎片跳转    Handler handler = new Handler(){        @Override        public void handleMessage(Message msg) {        vp.setCurrentItem(currentItem);        }    };}

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