android ViewPager使用案例

最新推荐文章于 2022-06-28 22:37:49 发布

原创最新推荐文章于 2022-06-28 22:37:49 发布 · 681 阅读

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本文详细介绍了Android中ViewPager的使用，通过实例展示了如何创建滑动页面效果，包括设置适配器、添加页面等内容，帮助开发者更好地理解和应用ViewPager。

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先上效果图：

public class appStart extends Activity {

	SharedPreferences sf;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		//判断是否首次运行
		sf=getSharedPreferences("count", MODE_WORLD_READABLE);
		int count = sf.getInt("start_count", 0);
		if(count ==0 ){
			Editor editor = sf.edit();
			 //存入数据
            editor.putInt("start_count", ++count);
            //提交修改	
            editor.commit();
            Intent intent = new Intent(appStart.this, GuideActivity.class);
			startActivity(intent);
			appStart.this.finish();
		}else{
			  Intent i = new Intent(appStart.this,
			  MainActivity.class);
			  startActivity(i);
			  appStart.this.finish();
		}
	}

}

public class GuideActivity extends Activity {

	private ViewPager viewPager;    
    private ArrayList<View> pageViews;    
    private ImageView imageView;    
    private ImageView[] imageViews; 
 // 包裹滑动图片LinearLayout  
    private ViewGroup main;  
   // 包裹小圆点的LinearLayout  
    private ViewGroup group;  
    //左箭头按钮  
    private ImageView imageViewLeft;  
    //右箭头按钮  
    private ImageView imageViewRight;  
    //当前页码  
    private int currentIndex;  
      
    //ImageView的alpha值     
    private int mAlpha = 0;  
    private boolean isHide;
    private Button btn;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		//将要显示的图片放到ArrayList当中，存到适配器中  
		LayoutInflater inflater = getLayoutInflater();
		pageViews = new ArrayList<View>();
		pageViews.add(inflater.inflate(R.layout.guide_item1, null));
		pageViews.add(inflater.inflate(R.layout.guide_item2, null));
		pageViews.add(inflater.inflate(R.layout.guide_item3, null));
		pageViews.add(inflater.inflate(R.layout.guide_item4, null));
		//将图片存放到ImageView集合中
        imageViews = new ImageView[pageViews.size()]; 
        main = (ViewGroup)inflater.inflate(R.layout.guide, null); 
        //获取存放底部导航点ViewGroup  
        group = (ViewGroup)main.findViewById(R.id.guide_point_ll);    
        viewPager = (ViewPager)main.findViewById(R.id.guide_viewpager);    
        imageViewLeft = (ImageView)main.findViewById(R.id.imageView1);  
        imageViewRight = (ImageView)main.findViewById(R.id.imageView2);  
        imageViewLeft.setAlpha(0);  
        imageViewRight.setAlpha(0); 
        
        //将小圆点放到imageView数组当中  
        for (int i = 0; i < pageViews.size(); i++) {    
        	System.out.println("pageViews.size() = " + pageViews.size());
            imageView = new ImageView(GuideActivity.this);    
            imageView.setLayoutParams(new LayoutParams(20,20));    
            imageView.setPadding(20, 0, 20, 0);    
            imageViews[i] = imageView;    
            if (i == 0) {    
             //默认选中第一张图片  
                imageViews[i].setBackgroundResource(R.drawable.green_point);    
            } else {    
                imageViews[i].setBackgroundResource(R.drawable.gray_point);    
            }    
            group.addView(imageViews[i]);    
        }
        btn=(Button)pageViews.get(3).findViewById(R.id.btn);
        btn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Intent i = new Intent(GuideActivity.this,
						  MainActivity.class);
						  startActivity(i);
						  GuideActivity.this.finish();
			}
		});
        setContentView(main);  
        
        viewPager.setAdapter(new GuidePageAdapter());    
        viewPager.setOnPageChangeListener(new GuidePageChangeListener()); 
        imageViewLeft.setOnClickListener(new ButtonListener());  
        imageViewRight.setOnClickListener(new ButtonListener());  
        
	} 
    
    //左右切换屏幕的按钮监听器  
    class ButtonListener implements OnClickListener{  
   
     @Override  
     public void onClick(View v) {  
         // TODO Auto-generated method stub  
         int showNext=0;  
         if(v.getId() == R.id.imageView1) {  
             System.out.println("点击了向左的按钮");  
             if(currentIndex ==0 )  
                 showNext = currentIndex;  
             else  
                 showNext = currentIndex-1;  
             viewPager.setCurrentItem(showNext);  
         }  
         if(v.getId() == R.id.imageView2){  
             System.out.println("点击了向右的按钮");  
             if(currentIndex == imageViews.length)  
                 showNext = currentIndex;  
             else  
                 showNext = currentIndex+1;  
             viewPager.setCurrentItem(showNext);  
         }  
             System.out.println("当前页码："+showNext);  
     }  
    } 
    
    /** 
     * 设置按钮渐显效果 
     */  
    private Handler mHandler = new Handler()  
    {  
        public void handleMessage(Message msg) {  
            if(msg.what==1 && mAlpha<255){             
                //通过设置不透明度设置按钮的渐显效果  
                mAlpha += 50;  
                  
                if(mAlpha>255)  
                    mAlpha=255;  
                  
                imageViewLeft.setAlpha(mAlpha);  
                imageViewLeft.invalidate();  
                imageViewRight.setAlpha(mAlpha);  
                imageViewRight.invalidate();  
                  
                if(!isHide && mAlpha<255)  
                    mHandler.sendEmptyMessageDelayed(1, 100);  
            }else if(msg.what==0 && mAlpha>0){  
                mAlpha -= 3;  
                  
                if(mAlpha<0)  
                    mAlpha=0;  
                imageViewLeft.setAlpha(mAlpha);  
                imageViewLeft.invalidate();  
                imageViewRight.setAlpha(mAlpha);  
                imageViewRight.invalidate();  
                  
                if(isHide && mAlpha>0)  
                    mHandler.sendEmptyMessageDelayed(0, 2);  
            }              
        }  
    };
    
    private void showImageButtonView(){  
        isHide = false;  
        mHandler.sendEmptyMessage(1);  
    }  
      
    private void hideImageButtonView(){  
        new Thread(){  
            public void run() {  
                try {  
                    isHide = true;  
                    mHandler.sendEmptyMessage(0);  
                } catch (Exception e) {  
                    ;  
                }  
            }  
        }.start();  
    } 
    
    public boolean dispatchTouchEvent(MotionEvent ev) {  
//        System.out.println("this is dispatch");  
//        System.out.println("触碰屏幕");  
           switch (ev.getAction()) {  
               case MotionEvent.ACTION_MOVE:  
               case MotionEvent.ACTION_DOWN:  
                   showImageButtonView();              
                   break;  
               case MotionEvent.ACTION_UP:  
                   hideImageButtonView();                  
                   break;  
           }  
             
             
        return super.dispatchTouchEvent(ev);  
    }
	 // 指引页面数据适配器,实现适配器方法  
    class GuidePageAdapter extends PagerAdapter {    
        @Override    
        public int getCount() {    
            return pageViews.size();    
        }    
        @Override    
        public boolean isViewFromObject(View arg0, Object arg1) {    
            return arg0 == arg1;    
        }    
        @Override    
        public int getItemPosition(Object object) {    
            // TODO Auto-generated method stub    
            return super.getItemPosition(object);    
        }    
        @Override    
        public void destroyItem(View arg0, int arg1, Object arg2) {    
            // TODO Auto-generated method stub    
            ((ViewPager) arg0).removeView(pageViews.get(arg1));    
        }    
        @Override    
        public Object instantiateItem(View arg0, int arg1) {    
            // TODO Auto-generated method stub    
            ((ViewPager) arg0).addView(pageViews.get(arg1));    
            return pageViews.get(arg1);    
        }    
        @Override    
        public void restoreState(Parcelable arg0, ClassLoader arg1) {    
            // TODO Auto-generated method stub    
        }    
        @Override    
        public Parcelable saveState() {    
            // TODO Auto-generated method stub    
            return null;    
        }    
        @Override    
        public void startUpdate(View arg0) {    
            // TODO Auto-generated method stub    
        }    
        @Override    
        public void finishUpdate(View arg0) {    
            // TODO Auto-generated method stub    
        }    
    } 
    // 指引页面更改事件监听器,左右滑动图片时候，小圆点变换显示当前图片位置  
    class GuidePageChangeListener implements OnPageChangeListener {    
         
        @Override    
        public void onPageScrollStateChanged(int arg0) {    
            // TODO Auto-generated method stub    
    
        }    
    
        @Override    
        public void onPageScrolled(int arg0, float arg1, int arg2) {    
            // TODO Auto-generated method stub    
    
        }    
    
        @Override    
        public void onPageSelected(int arg0) {    
         currentIndex = arg0;  
            for (int i = 0; i < imageViews.length; i++) {    
                imageViews[arg0].setBackgroundResource(R.drawable.green_point);  
                  
                if (arg0 != i) {    
                    imageViews[i].setBackgroundResource(R.drawable.gray_point);    
                }    
            }  
        }    
	}
}