android开发之gallery 实现滚动一张且短距离滑动实现滚动

首先gallery的特点就不用多说了吧，惯性滚动、半屏翻页，但是很多时候我们不需要它的这些特性。我今天就介绍一下 去掉惯性滚动 以及 短距离翻页的实现： 
代码先晒出来： 
main.xml： 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<com.mh.DetialGallery  android:id="@+id/gallery" android:layout_width="fill_parent"
        android:layout_height="fill_parent"  />
</LinearLayout>

DetialGallery 是自己继承的类。 

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;

public class main extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN ,
     WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.main);
        Gallery gallery = (Gallery) findViewById(R.id.gallery);
        gallery.setAdapter(new ImageAdapter(this));;

    }

    private int[] resIds = new int[]
         { R.drawable.a1, R.drawable.a2, R.drawable.a3,
           R.drawable.a4, R.drawable.a5, R.drawable.a6,
           R.drawable.a7, R.drawable.a8, R.drawable.a9
         };




 public class ImageAdapter extends BaseAdapter
    {
        int mGalleryItemBackground;
        private Context mContext;

        public ImageAdapter(Context context)
        {
            mContext = context;
        }

        public int getCount()
        {
            return resIds.length;
        }
        public Object getItem(int position)
        {
            return position;
        }

        public long getItemId(int position)
        {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent)
        {
            ImageView imageView = new ImageView(mContext);
            imageView.setImageResource(resIds[position]);
            imageView.setScaleType(ImageView.ScaleType.FIT_XY);
            imageView.setLayoutParams(new Gallery.LayoutParams(480, 800));   //分辨率自己定
            return imageView;
        }
    }

}

import android.content.Context;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.widget.Gallery;

public class DetialGallery extends Gallery {

    public DetialGallery(Context context ,AttributeSet attrSet) {
     super(context,attrSet);
     // TODO Auto-generated constructor stub
    }

 private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2)
   {
    return e2.getX() > e1.getX();
   }
 @Override
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
   float velocityY) {
  // TODO Auto-generated method stub
//  return super.onFling(e1, e2, 0, velocityY);//方法一：只去除翻页惯性
//  return false;


//方法二：只去除翻页惯性  注：没有被注释掉的代码实现了开始说的2种效果。
  int kEvent;
  if(isScrollingLeft(e1, e2)){
   //Check if scrolling left
   kEvent = KeyEvent.KEYCODE_DPAD_LEFT;
   }  else{
    //Otherwise scrolling right
    kEvent = KeyEvent.KEYCODE_DPAD_RIGHT;
    }
  onKeyDown(kEvent, null);
  return true;
  }
 }