Android编程滑动效果之倒影效果实现方法(附demo源码下载)

/** 反射倒影 */public boolean createReflectedImages() {  final int reflectionGap = 4;  int index = 0;  for (Map<String, Object> map : list) {    Integer id = (Integer) map.get("image");    Bitmap originalImage = BitmapFactory.decodeResource(mContext.getResources(), id); // 获取原始图片    int width = originalImage.getWidth();    int height = originalImage.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(originalImage, 0, height/2, width, height/2, matrix, false); // 截取原图下半部分    Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height / 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(originalImage, 0, 0, null); // 绘制原图    Paint paint = new Paint();    canvas.drawRect(0, height, width, height + reflectionGap, paint); // 绘制原图与倒影的间距    canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null); // 绘制倒影图    paint = new Paint();    LinearGradient shader = new LinearGradient(0, originalImage.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, height, width, 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 myGallery.LayoutParams(180, 240));    imageView.setScaleType(ScaleType.MATRIX);    mImages[index++] = imageView;  }  return true;}

public class myGallery extends Gallery {  private Camera mCamera = new Camera();  private int mMaxRotationAngle = 60; // 最大旋转角度 60  private int mMaxZoom = -120;  private int mCoveflowCenter;  public myGallery(Context context) {    super(context);    this.setStaticTransformationsEnabled(true);  }  public myGallery(Context context, AttributeSet attrs) {    super(context, attrs);    this.setStaticTransformationsEnabled(true);  }  public myGallery(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, 100.0f);    // As the angle of the view gets less, zoom in    if (rotation < mMaxRotationAngle) {      float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));      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();  }}

private void initRes(){  tvTitle = (TextView) findViewById(R.id.tvTitle);  gallery = (myGallery) findViewById(R.id.mygallery); // 获取自定义的myGallery控件  adapter = new ImageAdapter(this);  adapter.createReflectedImages(); // 创建倒影效果  gallery.setAdapter(adapter);  gallery.setOnItemSelectedListener(new OnItemSelectedListener() { // 设置选择事件监听    @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(Main.this, "img " + (position+1) + " selected", Toast.LENGTH_SHORT).show();    }  });}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="fill_parent"  android:layout_height="fill_parent"  android:orientation="vertical" >  <TextView    android:id="@+id/tvTitle"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_centerHorizontal="true"    android:textSize="16sp" />  <com.homer.reflect.myGallery    android:id="@+id/mygallery"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:layout_below="@id/tvTitle"    android:layout_marginTop="10dip" /></RelativeLayout>