Android中几种图像特效处理-白红宇

Android中几种图像特效处理

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发布时间：2019-06-24

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　　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:
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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:
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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns: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:
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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);