无线轮播+小圆点

最新推荐文章于 2019-01-14 21:34:31 发布

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本文介绍了一种在Android应用中实现轮播图的方法，通过自定义ViewPager和PagerAdapter，结合Handler定时切换图片，同时使用RadioGroup作为指示器。该方案适用于需要展示多张图片或广告的应用场景。

import android.os.Handler;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.RadioButton;
import android.widget.RadioGroup;

public class MainActivity extends AppCompatActivity {
private ViewPager vp;
private RadioGroup vg;
String[] paths = new String[]{
“http://img1.3lian.com/2015/w7/98/d/1.jpg“,
“http://img1.3lian.com/2015/w7/98/d/2.jpg“,
“http://img1.3lian.com/2015/w7/98/d/3.jpg“,
“http://img1.3lian.com/2015/w7/98/d/4.jpg”
};
Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
//得到当前的位置
int currentItem = vp.getCurrentItem();
vp.setCurrentItem(currentItem += 1);
//继续发送,轮播
handler.sendEmptyMessageDelayed(2, 2000);
}
};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        vp = (ViewPager) findViewById(R.id.fragment_shouye_vp);
        vg = (RadioGroup) findViewById(R.id.fragment_shouye_gp);
        vp.setAdapter(new MyViewPage(MainActivity.this,paths));
        handler.sendEmptyMessageDelayed(0, 2000);
        // 设置远点
        anniu();
        // 设置viewpager当前显示的条目(默认显示的条目)
        vp.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int arg0) {
                // TODO Auto-generated method stub

                vg.check(arg0 % paths.length);
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub

            }
        });
    }
private void anniu() {
    int wrop = RadioGroup.LayoutParams.WRAP_CONTENT;
    RadioGroup.LayoutParams params = new RadioGroup.LayoutParams(wrop, wrop);
    params.leftMargin = 5;

    for (int i = 0; i < paths.length; i++) {
        // 設置单选按钮
        RadioButton rb = new RadioButton(MainActivity.this);
        rb.setId(i);
        // 设置按钮图片
        rb.setButtonDrawable(R.drawable.x_dot_selector);
        // 添加到组里
        if (i == 0) {

            vg.addView(rb);
        } else {
            vg.addView(rb, params);
        }
    }
    // 默认选中第一个
    vg.check(0);
}

}

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.support.v4.view.ViewPager.LayoutParams;
import com.lidroid.xutils.BitmapUtils;
import android.widget.ImageView.ScaleType;
/**
* Created by Administrator on 2016/11/15.
*/
public class MyViewPage extends PagerAdapter {

private Context context;
private String []path ;
private BitmapUtils bitmapUtils;


public MyViewPage(Context context, String[] paths) {
    super();
    this.context = context;
    this.path = paths;


}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    // TODO Auto-generated method stub
    // 得到网络图片的地址
  //  String img=list.get(position%list.size()).getPicUrl();
    String img=path[position%path.length];
    // 得到imageView对象
    ImageView imageView = new ImageView(context);
    //充满整个ViewPage
    imageView.setScaleType(ScaleType.FIT_XY);
    // 得到布局参数对象
    LayoutParams layoutParams = new LayoutParams();
    layoutParams.height = LayoutParams.FILL_PARENT;
    // 设置宽为填充父窗体
    layoutParams.width = LayoutParams.FILL_PARENT;
    imageView.setLayoutParams(layoutParams);
    // 参数一：显示图片的容器
    // 参数二：图片路径
    BitmapUtils bitmapUtils = new BitmapUtils(context);
    bitmapUtils.display(imageView,img);
    container.addView(imageView);


    return imageView;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // TODO Auto-generated method stub
    container.removeView((View) object);

}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return Integer.MAX_VALUE;
}

@Override
public boolean isViewFromObject(View arg0, Object arg1) {
    // TODO Auto-generated method stub
    return arg0 == arg1;
}

}