Android 图片处理的方法

package com.img.util;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.Drawable;

public class ImgUtil {
    // 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 scaleWidth = ((float) w / width);
        float scaleHeight = ((float) h / height);
        matrix.postScale(scaleWidth, 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;
    }

    // 圆角图片
    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;
    }
}

package com.img.util;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.ImageView;

public class MainActivity extends Activity {
    private ImageView mImageView01, mImageView02;

    @Override
    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 = ImgUtil.drawableToBitmap(drawable);
        // 缩放图片
        Bitmap zoomBitmap = ImgUtil.zoomBitmap(bitmap, 100, 100);
        // 获取圆角图片
        Bitmap roundBitmap = ImgUtil
                .getRoundedCornerBitmap(zoomBitmap, 10.0f);
        // 获取倒影图片
        Bitmap reflectBitmap = ImgUtil
                .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);
    }
}