android 实现倒影

首先，文章中出现的Gallery 已经不再适用，替代方法请看我的另一篇文章http://blog.csdn.net/xiangzhihong8/article/details/51120460

不过对于文章中说的倒影的原理是可以借鉴的。

1.图片的显示以及切换主要是自定义了一个Gallery

下面是代码myGallery.java：

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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;

@SuppressWarnings("deprecation")

public class myGallery extends Gallery {

private Camera mCamera = new Camera();

private int mMaxRotationAngle = 60; //图片偏转角度 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;

}

/** 获得Gallery中心到边界的距离*/

private int getCenterOfCoverflow() {

return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();

}

/** 获得View中心位置到边界的距离 */

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, 200.0f);

// 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();

}

}

2.接下来就是要为图片添加倒影了，用过PhotoShop的都知道添加倒影就是将原有图片倒置，设置渐变式的显示，再将其放在原图片下面就行了，这里的方法也是一样

在为Gallery添加图片的同时，为每个图片添加倒影，需要在Adapter中做

下面就是相关代码 ImageAdapter.java：

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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 ImageAdapter extends BaseAdapter {

private ImageView[] mImages; // 存储每个图片的ImageView

private Context mContext;

public List<Map<String, Object>> list;

public Integer[] imgs = { R.drawable.img1, R.drawable.img2,

R.drawable.img3, R.drawable.img4, R.drawable.img5 };

public String[] titles = { "孙燕姿", "就是要唱歌", "微笑", "大海", "漂亮"};

public ImageAdapter(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()];

}

/**

* 创建倒影效果

*/

@SuppressWarnings("deprecation")

public boolean createReflectedImages() {

final int reflectionGap = 4;//原图与倒影之间的间隙

int index = 0;

for (Map<String, Object> map : list) {

Integer id = (Integer) map.get("image");

Bitmap originalImage = BitmapFactory.decodeResource(

mContext.getResources(), id); // 获得图片资源

// 获得图片的长宽

int width = originalImage.getWidth();

int height = originalImage.getHeight();

Matrix matrix = new Matrix();

matrix.preScale(1, -1); // 实现图片的反转

Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,

height / 2, width, height / 2, matrix, false); // 创建反转后的图片Bitmap对象，图片高是原图的一半

Bitmap bitmapWithReflection = Bitmap.createBitmap(width,

(height + height / 2), Config.ARGB_8888); // 创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍

Canvas canvas = new Canvas(bitmapWithReflection);

canvas.drawBitmap(originalImage, 0, 0, null); // 创建画布对象，将原图画于画布，起点是原点位置

Paint paint = new Paint();

canvas.drawRect(0, height, width, height + reflectionGap, paint);

canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null); // 将反转后的图片画到画布中

paint = new Paint();

LinearGradient shader = new LinearGradient(0,

originalImage.getHeight(), 0,

bitmapWithReflection.getHeight() + reflectionGap,

0x70ffffff, 0x00ffffff, TileMode.MIRROR);// 创建线性渐变LinearGradient对象

paint.setShader(shader); // 绘制

paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));//倒影遮罩效果

canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()

+ reflectionGap, paint); // 画布画出反转图片大小区域，然后把渐变效果加到其中，就出现了图片的倒影效果

ImageView imageView = new ImageView(mContext);

imageView.setImageBitmap(bitmapWithReflection); // 设置带倒影的Bitmap

//设置ImageView的大小，可以根据图片大小设置

// imageView.setLayoutParams(newmyGallery.LayoutParams(width,height));

imageView.setLayoutParams(new myGallery.LayoutParams(250, 500));//设置ImageView的大小，可根据需要设置固定宽高

imageView.setScaleType(ScaleType.FIT_CENTER);//将图片按比例缩放

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]; // 获得Gallery中对应位置的ImageView

}

public float getScale(boolean focused, int offset) {

return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset)));

}

}

3.然后在主Activity中进行配置Main.java：

[java] view
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import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.AdapterView.OnItemSelectedListener;

import android.widget.TextView;

import android.widget.Toast;

public class Main extends Activity {

private TextView tvTitle;

private myGallery gallery;

private ImageAdapter adapter;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

initRes();

}

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();

}

});

}

}

4.最后是页面布局main.xml：

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<?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_alignParentLeft="true"

android:layout_centerVertical="true" />

</RelativeLayout>

5.大功告成啦！看看效果：



欢迎下载源码！