第一章:初入Android大门(Gallery拖动相片特效)

效果:




main.xml

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout
android:id="@+id/widget0"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
>

<Gallery
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x="43px"
android:layout_y="142px"
>
</Gallery>
</AbsoluteLayout>

package gallery.test;

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

public class GalleryTest extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        /** 获得 Gallery对象组件*/
        ((Gallery)findViewById(R.id.image)).setAdapter(new ImageAdapter(this));
    }
    public class ImageAdapter extends BaseAdapter{
    	private Context myContext;
    	/** 定义图片*/
    	private int[] myImages={
    			android.R.drawable.btn_minus,
    			android.R.drawable.btn_radio,
    			android.R.drawable.ic_lock_idle_low_battery,
    			android.R.drawable.ic_menu_camera,
    	};
    	/** 存储Context*/
    	public ImageAdapter(Context c){
    		this.myContext=c;
    		
    	}
    	/** 获得图片数量*/
		public int getCount() {
			// TODO Auto-generated method stub
			return this.myImages.length;
		}
		/** 获得目前图像数组ID*/
		@Override
		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}
		/**取得显示图像View,传入数组ID值读取数组图像*/
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			/**实例化ImageView对象*/
			ImageView i=new ImageView(this.myContext);
			/**设置图片*/
			i.setImageResource(this.myImages[position]);
			/**设置View的大小*/
			i.setScaleType(ImageView.ScaleType.FIT_XY);
			/**设置ImageView对象宽度和高度*/
			i.setLayoutParams(new Gallery.LayoutParams(120,120));
			return i;
		}
		/**距离中央距离位移梁 利用getScale返回View大小*/
    	public float getScale(boolean flg,int offset){
    		return Math.max(0,1.0f/(float)Math.pow(2, Math.abs(offset)));
    	}
    	
    }
}

评论

1 楼 silencetq 2011-09-14  

请教一下，这个效果拖动后，会出现一层黑色的膜，可以怎么去掉呢？