Android中有很多图片特效处理技巧,比如圆角、倒影,今天为大家分享一个实例,本例主要是先获取壁纸(getWallpaper()),然后对当前壁纸的一些特效处理。
第一步:新建一个Android工程命名为ImageDemo,工程结构如下:
第二步:新建一个.java文件,命名为ImageUtil.java,在里面定义一些图片处理方法,代码如下:
Java代码:
- view plaincopy to clipboardprint?
- package com.android.tutor;
- import android.graphics.Bitmap;
- import android.graphics.Canvas;
- import android.graphics.LinearGradient;
- import android.graphics.Matrix;
- import android.graphics.Paint;
- import android.graphics.PixelFormat;
- import android.graphics.PorterDuffXfermode;
- import android.graphics.Rect;
- import android.graphics.RectF;
- import android.graphics.Bitmap.Config;
- import android.graphics.PorterDuff.Mode;
- import android.graphics.Shader.TileMode;
- import android.graphics.drawable.Drawable;
- public class ImageUtil {
- //放大缩小图片
- public static Bitmap zoomBitmap(Bitmap bitmap,int w,int h){
- int width = bitmap.getWidth();
- int height = bitmap.getHeight();
- Matrix matrix = new Matrix();
- float scaleWidht = ((float)w / width);
- float scaleHeight = ((float)h / height);
- matrix.postScale(scaleWidht, scaleHeight);
- Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
- return newbmp;
- }
- //将Drawable转化为Bitmap
- public static Bitmap drawableToBitmap(Drawable drawable){
- int width = drawable.getIntrinsicWidth();
- int height = drawable.getIntrinsicHeight();
- Bitmap bitmap = Bitmap.createBitmap(width, height,
- drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
- : Bitmap.Config.RGB_565);
- Canvas canvas = new Canvas(bitmap);
- drawable.setBounds(0,0,width,height);
- drawable.draw(canvas);
- return bitmap;
- }
- //获得圆角图片的方法
- public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx){
- Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap
- .getHeight(), Config.ARGB_8888);
- Canvas canvas = new Canvas(output);
- final int color = 0xff424242;
- final Paint paint = new Paint();
- final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
- final RectF rectF = new RectF(rect);
- paint.setAntiAlias(true);
- canvas.drawARGB(0, 0, 0, 0);
- paint.setColor(color);
- canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
- paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
- canvas.drawBitmap(bitmap, rect, rect, paint);
- return output;
- }
- //获得带倒影的图片方法
- public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){
- final int reflectionGap = 4;
- int width = bitmap.getWidth();
- int height = bitmap.getHeight();
- Matrix matrix = new Matrix();
- matrix.preScale(1, -1);
- Bitmap reflectionImage = Bitmap.createBitmap(bitmap,
- 0, height/2, width, height/2, matrix, false);
- Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888);
- Canvas canvas = new Canvas(bitmapWithReflection);
- canvas.drawBitmap(bitmap, 0, 0, null);
- Paint deafalutPaint = new Paint();
- canvas.drawRect(0, height,width,height + reflectionGap,
- deafalutPaint);
- canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
- Paint paint = new Paint();
- LinearGradient shader = new LinearGradient(0,
- bitmap.getHeight(), 0, bitmapWithReflection.getHeight()
- + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
- paint.setShader(shader);
- // Set the Transfer mode to be porter duff and destination in
- paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
- // Draw a rectangle using the paint with our linear gradient
- canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
- + reflectionGap, paint);
- return bitmapWithReflection;
- }
- }
第三步:修改main.xml布局文件,主要放了两个ImageView控件,代码如下:
Java代码:
- view plaincopy to clipboardprint?
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:orientation="vertical"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- >
- <ImageView
- android:id="@+id/image01"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:padding="10px"
- />
- <ImageView
- android:id="@+id/image02"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:padding="10px"
- />
- </LinearLayout>
第四步:修改主核心程序,ImageDemo.java,代码如下:
Java代码:
- view plaincopy to clipboardprint?
- package com.android.tutor;
- import android.app.Activity;
- import android.graphics.Bitmap;
- import android.graphics.drawable.Drawable;
- import android.os.Bundle;
- import android.widget.ImageView;
- public class Imagedemo extends Activity {
- private ImageView mImageView01,mImageView02;
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- setupViews();
- }
- private void setupViews(){
- mImageView01 = (ImageView)findViewById(R.id.image01);
- mImageView02 = (ImageView)findViewById(R.id.image02);
- //获取壁纸返回值是Drawable
- Drawable drawable = getWallpaper();
- //将Drawable转化为Bitmap
- Bitmap bitmap = ImageUtil.drawableToBitmap(drawable);
- //缩放图片
- Bitmap zoomBitmap = ImageUtil.zoomBitmap(bitmap, 100, 100);
- //获取圆角图片
- Bitmap roundBitmap = ImageUtil.getRoundedCornerBitmap(zoomBitmap, 10.0f);
- //获取倒影图片
- Bitmap reflectBitmap = ImageUtil.createReflectionImageWithOrigin(zoomBitmap);
- //这里可以让Bitmap再转化为Drawable
- // Drawable roundDrawable = new BitmapDrawable(roundBitmap);
- // Drawable reflectDrawable = new BitmapDrawable(reflectBitmap);
- // mImageView01.setBackgroundDrawable(roundDrawable);
- // mImageView02.setBackgroundDrawable(reflectDrawable);
- mImageView01.setImageBitmap(roundBitmap);
- mImageView02.setImageBitmap(reflectBitmap);
- }
- }