使用Gallery来实现图片的3D效果

来源：互联网发布：裁员补偿标准n的算法编辑：程序博客网时间：2024/05/01 17:00

利用Gallery自定义一个3D效果的图片列表，下面让大家看看具体实现：

看看自定义的GalleryView：

package com.mythou.grallery3d;

import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;
import android.widget.ImageView;

public class GalleryView extends Gallery
{
   private Camera mCamera = new Camera();
   private int mMaxRotationAngle = 45;       // 最大旋转角度 60
   private int mMaxZoom = -120;
   private int mCoveflowCenter;

   public GalleryView(Context context)
   {
       super(context);
       this.setStaticTransformationsEnabled(true);
   }

   public GalleryView(Context context, AttributeSet attrs)
   {
       super(context, attrs);
       this.setStaticTransformationsEnabled(true);
   }

   public GalleryView(Context context, AttributeSet attrs, int defStyle)
   {
       super(context, attrs, defStyle);
       this.setStaticTransformationsEnabled(true);
   }

   public int getMaxRotationAngle()
   {
       return mMaxRotationAngle;
   }

   public void setMaxRotationAngle(int maxRotationAngle)
   {
       mMaxRotationAngle = maxRotationAngle;
   }

   public int getMaxZoom()
   {
       return mMaxZoom;
   }

   public void setMaxZoom(int maxZoom)
   {
       mMaxZoom = maxZoom;
   }

   /** 获取Gallery的中心x */
   private int getCenterOfCoverflow()
   {
       return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();
   }

   /** 获取View的中心x */
   private static int getCenterOfView(View view) {
       return view.getLeft() + view.getWidth() / 2;
   }

   @Override
   protected void onSizeChanged(int w, int h, int oldw, int oldh)
   {
       mCoveflowCenter = getCenterOfCoverflow();
       super.onSizeChanged(w, h, oldw, oldh);
   }

   @Override
   protected boolean getChildStaticTransformation(View child, Transformation trans)
   {
       final int childCenter = getCenterOfView(child);
       final int childWidth = child.getWidth();
       int rotationAngle = 0;

       trans.clear();
       trans.setTransformationType(Transformation.TYPE_BOTH);       // alpha 和 matrix 都变换

       if (childCenter == mCoveflowCenter)
       {   // 正中间的childView
           transformImageBitmap((ImageView) child, trans, 0);
       }
       else
       {       // 两侧的childView
           rotationAngle = (int) ( ( (float) (mCoveflowCenter - childCenter) / childWidth ) * mMaxRotationAngle );
           if (Math.abs(rotationAngle) > mMaxRotationAngle)
           {
               rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;
           }
           transformImageBitmap((ImageView) child, trans, rotationAngle);
       }

       return true;
   }

   private void transformImageBitmap(ImageView child, Transformation trans, int rotationAngle)
   {
       mCamera.save();

       final Matrix imageMatrix = trans.getMatrix();
       final int imageHeight = child.getLayoutParams().height;
       final int imageWidth = child.getLayoutParams().width;
       final int rotation = Math.abs(rotationAngle);

       // 在Z轴上正向移动camera的视角，实际效果为放大图片; 如果在Y轴上移动，则图片上下移动; X轴上对应图片左右移动。
       mCamera.translate(0.0f, 0.0f, -20.0f);

       // As the angle of the view gets less, zoom in
       if (rotation < mMaxRotationAngle)
       {
           float zoomAmount = (float) (mMaxZoom + (rotation * 1.0));
           mCamera.translate(0.0f, 0.0f, zoomAmount);
       }

       mCamera.rotateY(rotationAngle);       // rotationAngle 为正，沿y轴向内旋转；为负，沿y轴向外旋转

       mCamera.getMatrix(imageMatrix);
       imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));
       imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));

       mCamera.restore();
   }
}

与此同时我们还需要一个Adapter，这里我们用ImageHeadAdapter来继承BaseADapter来实现：

在ImageHeadAdapter里我们要自己实现阴影的效果：

/** 反射倒影 */
   public boolean createReflectedImages()
   {
       final int reflectionGap = 4;
       final int Height = 200;
       int index = 0;
       for (Map<String, Object> map : list) {
           Integer id = (Integer) map.get("image");
           // 获取原始图片
           Bitmap originalImage = BitmapFactory.decodeResource(mContext.getResources(), id);
           int width = originalImage.getWidth();
           int height = originalImage.getHeight();
           float scale = Height / (float)height;

           Matrix sMatrix = new Matrix();
           sMatrix.postScale(scale, scale);
           Bitmap miniBitmap = Bitmap.createBitmap(originalImage, 0, 0,
                   originalImage.getWidth(), originalImage.getHeight(), sMatrix, true);

           //是否原图片数据，节省内存
           originalImage.recycle();

           int mwidth = miniBitmap.getWidth();
           int mheight = miniBitmap.getHeight();
           Matrix matrix = new Matrix();
           matrix.preScale(1, -1);           // 图片矩阵变换（从低部向顶部的倒影）
           Bitmap reflectionImage = Bitmap.createBitmap(miniBitmap, 0, mheight/2, mwidth, mheight/2, matrix, false);   // 截取原图下半部分
           Bitmap bitmapWithReflection = Bitmap.createBitmap(mwidth, (mheight + mheight / 2), Config.ARGB_8888);           // 创建倒影图片（高度为原图3/2）

           Canvas canvas = new Canvas(bitmapWithReflection);   // 绘制倒影图（原图 + 间距 + 倒影）
           canvas.drawBitmap(miniBitmap, 0, 0, null);       // 绘制原图
           Paint paint = new Paint();
           canvas.drawRect(0, mheight, mwidth, mheight + reflectionGap, paint);       // 绘制原图与倒影的间距
           canvas.drawBitmap(reflectionImage, 0, mheight + reflectionGap, null);   // 绘制倒影图

           paint = new Paint();
           LinearGradient shader = new LinearGradient(0, miniBitmap.getHeight(), 0, bitmapWithReflection.getHeight()
                   + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
           paint.setShader(shader);   // 线性渐变效果
           paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));       // 倒影遮罩效果
           canvas.drawRect(0, mheight, mwidth, bitmapWithReflection.getHeight() + reflectionGap, paint);       // 绘制倒影的阴影效果

           ImageView imageView = new ImageView(mContext);
           imageView.setImageBitmap(bitmapWithReflection);       // 设置倒影图片
           imageView.setLayoutParams(new GalleryView.LayoutParams((int)(width * scale),
                   (int)(mheight * 3 / 2.0 + reflectionGap)));
           imageView.setScaleType(ScaleType.MATRIX);
           mImages[index++] = imageView;
       }
       return true;
   }

下面是ImageHeadAdapter的具体实现：

package com.mythou.grallery3d;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Shader.TileMode;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;

public class ImageHeadAdapter extends BaseAdapter
{
   private ImageView[] mImages;       // 保存倒影图片的数组

   private Context mContext;
   public List<Map<String, Object>> list;


   public Integer[] imgs = { R.drawable.image01, R.drawable.image02, R.drawable.image03,
                              R.drawable.image04, R.drawable.image05};
   public String[] titles = { "美图01", "美图02", "美图03", "美图04", "美图05", "美图06", "美图07"};

   public ImageHeadAdapter(Context c)
   {
       this.mContext = c;
       list = new ArrayList<Map<String, Object>>();
       for (int i = 0; i < imgs.length; i++) {
           HashMap<String, Object> map = new HashMap<String, Object>();
           map.put("image", imgs[i]);
           list.add(map);
       }
       mImages = new ImageView[list.size()];
   }

   /** 反射倒影 */
   public boolean createReflectedImages()
   {
       final int reflectionGap = 4;
       final int Height = 200;
       int index = 0;
       for (Map<String, Object> map : list) {
           Integer id = (Integer) map.get("image");
           // 获取原始图片
           Bitmap originalImage = BitmapFactory.decodeResource(mContext.getResources(), id);
           int width = originalImage.getWidth();
           int height = originalImage.getHeight();
           float scale = Height / (float)height;

           Matrix sMatrix = new Matrix();
           sMatrix.postScale(scale, scale);
           Bitmap miniBitmap = Bitmap.createBitmap(originalImage, 0, 0,
                   originalImage.getWidth(), originalImage.getHeight(), sMatrix, true);

           //是否原图片数据，节省内存
           originalImage.recycle();

           int mwidth = miniBitmap.getWidth();
           int mheight = miniBitmap.getHeight();
           Matrix matrix = new Matrix();
           matrix.preScale(1, -1);           // 图片矩阵变换（从低部向顶部的倒影）
           Bitmap reflectionImage = Bitmap.createBitmap(miniBitmap, 0, mheight/2, mwidth, mheight/2, matrix, false);   // 截取原图下半部分
           Bitmap bitmapWithReflection = Bitmap.createBitmap(mwidth, (mheight + mheight / 2), Config.ARGB_8888);           // 创建倒影图片（高度为原图3/2）

           Canvas canvas = new Canvas(bitmapWithReflection);   // 绘制倒影图（原图 + 间距 + 倒影）
           canvas.drawBitmap(miniBitmap, 0, 0, null);       // 绘制原图
           Paint paint = new Paint();
           canvas.drawRect(0, mheight, mwidth, mheight + reflectionGap, paint);       // 绘制原图与倒影的间距
           canvas.drawBitmap(reflectionImage, 0, mheight + reflectionGap, null);   // 绘制倒影图

           paint = new Paint();
           LinearGradient shader = new LinearGradient(0, miniBitmap.getHeight(), 0, bitmapWithReflection.getHeight()
                   + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
           paint.setShader(shader);   // 线性渐变效果
           paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));       // 倒影遮罩效果
           canvas.drawRect(0, mheight, mwidth, bitmapWithReflection.getHeight() + reflectionGap, paint);       // 绘制倒影的阴影效果

           ImageView imageView = new ImageView(mContext);
           imageView.setImageBitmap(bitmapWithReflection);       // 设置倒影图片
           imageView.setLayoutParams(new GalleryView.LayoutParams((int)(width * scale),
                   (int)(mheight * 3 / 2.0 + reflectionGap)));
           imageView.setScaleType(ScaleType.MATRIX);
           mImages[index++] = imageView;
       }
       return true;
   }

   @Override
   public int getCount() {
       return imgs.length;
   }

   @Override
   public Object getItem(int position) {
       return mImages[position];
   }

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

   @Override
   public View getView(int position, View convertView, ViewGroup parent) {
       return mImages[position];       // 显示倒影图片（当前获取焦点）
   }

   public float getScale(boolean focused, int offset) {
       return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset)));
   }

}

最后我们看一下MainActivity：

package com.mythou.grallery3d;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

   private TextView tvTitle;
   private GalleryView gallery;
   private ImageHeadAdapter adapter;

   @Override
   public void onCreate(Bundle savedInstanceState) {
       requestWindowFeature(Window.FEATURE_NO_TITLE);
       super.onCreate(savedInstanceState);
       setContentView(R.layout.grallery_layout);

       initRes();
   }

   private void initRes(){
       tvTitle = (TextView) findViewById(R.id.tvTitle);
       gallery = (GalleryView) findViewById(R.id.mygallery);

       adapter = new ImageHeadAdapter(this);
       adapter.createReflectedImages();
       gallery.setAdapter(adapter);

       gallery.setOnItemSelectedListener(new OnItemSelectedListener() {
           @Override
           public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
               tvTitle.setText(adapter.titles[position]);
           }

           @Override
           public void onNothingSelected(AdapterView<?> parent) {
           }
       });

       gallery.setOnItemClickListener(new OnItemClickListener() {           // 设置点击事件监听
           @Override
           public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
               Toast.makeText(Grallery3DActivity.this, "img " + (position+1) + " selected", Toast.LENGTH_SHORT).show();
           }
       });
   }
}

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