Android特效第三篇：自定义Gallery实战(仿网易) .

Android系统提供了一个Gallery画廊控件，在项目很多时候都会用到Gallery，比如新浪首页的广告，网易看客户端首页等随处可见，今天我自己定义了一个仿网易的Gallery与大家共享。

     首先请看效果图：

                                         

代码：

package com.jefry.gallery;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * @author jefry
 *
 */
public class MyGallery extends FrameLayout {
    List<Showing> showings = new ArrayList<Showing>();
    private static final double GALLERY_IMAGE_HORIZONTAL_RATIO = 1.0;
    private static final double GALLERY_IMAGE_VERTICAL_RATIO = 1.0;
    private static final int GALLERY_SPACING = 2;
    private Context mContext;
    private PromotionImages promotionImages;
    private LinearLayout mBottomLayout;
    private TextView tips;
    private int mPcount;
    private ImageView[] icons;
    public MyGallery(Context context) {
        super(context);
    }

    public MyGallery(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        promotionImages = new PromotionImages(context);
        LayoutParams layoutParams = new LayoutParams(android.view.ViewGroup.LayoutParams.FILL_PARENT,android.view.ViewGroup.LayoutParams.FILL_PARENT);
        layoutParams.bottomMargin = 20;
        this.addView(promotionImages, layoutParams);
        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        View indicator = inflater.inflate(R.layout.promotion_hint,null);
        this.addView(indicator);
        //
        mBottomLayout = (LinearLayout) indicator.findViewById(R.id.promotion_index_layout);
        tips      = (TextView) indicator.findViewById(R.id.promotion_tip);
        initBottomIcons();
    }




    class PromotionImages extends Gallery {

        PromotionImagesAdapter promotionAdapter;
        public PromotionImages(Context context) {
            super(context);
            this.setSpacing(GALLERY_SPACING);
            promotionAdapter = new PromotionImagesAdapter(context);
            this.setAdapter(promotionAdapter);

            this.setOnItemSelectedListener(new OnItemSelectedListener() {

                public void onItemSelected(AdapterView<?> parent, View view,
                        int position, long id) {
                     update(position);
                }


                public void onNothingSelected(AdapterView<?> parent) {

                }
            });
        }


        private final void update(int selected) {
            tips.setText(showings.get(selected).getText());
            for (int i = 0; i < mPcount; i++) {
                   if (selected == i) {
                        icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_focus));
                    } else {
                        icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_default));
                    }
              }
            }
        }


       private final void initBottomIcons() {
         mPcount = showings.size();
         icons = new ImageView[mPcount];
         mBottomLayout.removeAllViews();
         mBottomLayout.setWeightSum(mPcount);
        //
        for (int i = 0; i < mPcount; i++) {
            icons[i] = new ImageView(mContext);
            if(i == 0) icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_focus));
            else icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_default));
            mBottomLayout.addView(icons[i]);
        }
    }

        private final class PromotionImagesAdapter extends BaseAdapter {
            public PromotionImagesAdapter(Context context) {
                Resources res = getResources();

                Bitmap bmp = BitmapFactory.decodeResource(res,
                        R.drawable.test2);
                Showing show1 = new Showing();
                show1.setBitmap(bmp);
                show1.setText("jefry_1");

                Bitmap bmp1 = BitmapFactory.decodeResource(res,
                        R.drawable.test1);
                Showing show2 = new Showing();
                show2.setBitmap(bmp1);
                show2.setText("jefry_2");

                Bitmap bmp3 = BitmapFactory.decodeResource(res,
                        R.drawable.test3);
                Showing show3 = new Showing();
                show3.setBitmap(bmp3);
                show3.setText("jefry_3");

                showings.add(show1);
                showings.add(show2);
                showings.add(show3);

            }


            public int getCount() {
                return showings.size();
            }


            public Object getItem(int position) {
                return position;
            }


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


            public View getView(final int position, final View convertView,
                    ViewGroup parent) {
                //System.out.println("showings = " + showings.size());
                //System.out.println("position=" + position);
                final Showing promotion = showings.get(position);
                ImageView promotionImage = (ImageView) convertView;
                if (promotionImage == null) {
                    promotionImage = new ImageView(mContext);
                    System.out.println("postion=" + position + ",promotion.getBitmap()1 = "+ promotion.getBitmap());
                }
                int width = (int) (MyGallery.this.getWidth() * GALLERY_IMAGE_HORIZONTAL_RATIO);
                int height = (int) (MyGallery.this.getHeight() * GALLERY_IMAGE_VERTICAL_RATIO);
                promotionImage.setLayoutParams(new Gallery.LayoutParams(width,height));
                promotionImage.setScaleType(ImageView.ScaleType.CENTER);
                promotionImage.setScaleType(ImageView.ScaleType.FIT_XY);
                System.out.println("postion=" + position + ",promotion.getBitmap() = "+ promotion.getBitmap());
                promotionImage.setImageBitmap(promotion.getBitmap());
                return promotionImage;
            }
        }
    }

package com.jefry.gallery;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * @author jefry
 *
 */
public class MyGallery extends FrameLayout {
	List<Showing> showings = new ArrayList<Showing>();
	private static final double GALLERY_IMAGE_HORIZONTAL_RATIO = 1.0;
	private static final double GALLERY_IMAGE_VERTICAL_RATIO = 1.0;
	private static final int GALLERY_SPACING = 2;
    private Context mContext;
    private PromotionImages promotionImages;
    private LinearLayout mBottomLayout;
    private TextView tips;
    private int mPcount;
    private ImageView[] icons;
	public MyGallery(Context context) {
		super(context);
	}

	public MyGallery(Context context, AttributeSet attrs) {
		super(context, attrs);
		mContext = context;
		promotionImages = new PromotionImages(context);
		LayoutParams layoutParams = new LayoutParams(android.view.ViewGroup.LayoutParams.FILL_PARENT,android.view.ViewGroup.LayoutParams.FILL_PARENT);
		layoutParams.bottomMargin = 20;
		this.addView(promotionImages, layoutParams);
		LayoutInflater inflater = ((Activity) context).getLayoutInflater();
		View indicator = inflater.inflate(R.layout.promotion_hint,null);
		this.addView(indicator);
		//
		mBottomLayout = (LinearLayout) indicator.findViewById(R.id.promotion_index_layout);
	    tips	  = (TextView) indicator.findViewById(R.id.promotion_tip);
	    initBottomIcons();
	}
	
	
	

	class PromotionImages extends Gallery {
       
		PromotionImagesAdapter promotionAdapter;
		public PromotionImages(Context context) {
			super(context);
			this.setSpacing(GALLERY_SPACING);
			promotionAdapter = new PromotionImagesAdapter(context);
			this.setAdapter(promotionAdapter);
			
			this.setOnItemSelectedListener(new OnItemSelectedListener() {
				
				public void onItemSelected(AdapterView<?> parent, View view,
						int position, long id) {
					 update(position);
				}

		
				public void onNothingSelected(AdapterView<?> parent) {
					
				}
			});
		}
		
		
		private final void update(int selected) {
		    tips.setText(showings.get(selected).getText());
			for (int i = 0; i < mPcount; i++) {
				   if (selected == i) {
						icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_focus));
					} else {
						icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_default));
				    }
			  }
		    }
		}
	
	
	   private final void initBottomIcons() {
		 mPcount = showings.size();
		 icons = new ImageView[mPcount];
		 mBottomLayout.removeAllViews();
		 mBottomLayout.setWeightSum(mPcount);
		//
		for (int i = 0; i < mPcount; i++) {
			icons[i] = new ImageView(mContext);
			if(i == 0) icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_focus));
			else icons[i].setBackgroundDrawable(getResources().getDrawable(R.drawable.promotion_select_default));
			mBottomLayout.addView(icons[i]);
		}
	}

		private final class PromotionImagesAdapter extends BaseAdapter {
			public PromotionImagesAdapter(Context context) {
				Resources res = getResources();

				Bitmap bmp = BitmapFactory.decodeResource(res,
						R.drawable.test2);
				Showing show1 = new Showing();
				show1.setBitmap(bmp);
				show1.setText("jefry_1");

				Bitmap bmp1 = BitmapFactory.decodeResource(res,
						R.drawable.test1);
				Showing show2 = new Showing();
				show2.setBitmap(bmp1);
				show2.setText("jefry_2");
                
				Bitmap bmp3 = BitmapFactory.decodeResource(res,
						R.drawable.test3);
				Showing show3 = new Showing();
				show3.setBitmap(bmp3);
				show3.setText("jefry_3");

				showings.add(show1);
				showings.add(show2);
				showings.add(show3);

			}

			
			public int getCount() {
				return showings.size();
			}

			
			public Object getItem(int position) {
				return position;
			}

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

			
			public View getView(final int position, final View convertView,
					ViewGroup parent) {
				//System.out.println("showings = " + showings.size());
                //System.out.println("position=" + position);
				final Showing promotion = showings.get(position);
				ImageView promotionImage = (ImageView) convertView; 
				if (promotionImage == null) {
					promotionImage = new ImageView(mContext);
					System.out.println("postion=" + position + ",promotion.getBitmap()1 = "+ promotion.getBitmap());
				}
				int width = (int) (MyGallery.this.getWidth() * GALLERY_IMAGE_HORIZONTAL_RATIO);
				int height = (int) (MyGallery.this.getHeight() * GALLERY_IMAGE_VERTICAL_RATIO);
				promotionImage.setLayoutParams(new Gallery.LayoutParams(width,height));
				promotionImage.setScaleType(ImageView.ScaleType.CENTER);
				promotionImage.setScaleType(ImageView.ScaleType.FIT_XY);
				System.out.println("postion=" + position + ",promotion.getBitmap() = "+ promotion.getBitmap());
				promotionImage.setImageBitmap(promotion.getBitmap());
				return promotionImage;
			}
		}
	}

源码下载： http://download.csdn.net/detail/jefry_xdz/4521377