记录一个好用的Bitmap工具类

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u010886975/article/details/85245606

package com.why.project.bitmaputildemo.utils;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.PixelFormat;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

public class BitmapUtil {
    public static Bitmap temp;

    /**根据指定的高度进行缩放（source是bitmap）*/
    public static Bitmap bitmapZoomByHeight(Bitmap srcBitmap, float newHeight) {
        float scale = newHeight / (((float)srcBitmap.getHeight()));
        return BitmapUtil.bitmapZoomByScale(srcBitmap, scale, scale);
    }
    /**根据指定的高度进行缩放（source是drawable）*/
    public static Bitmap bitmapZoomByHeight(Drawable drawable, float newHeight) {
        Bitmap bitmap = BitmapUtil.drawableToBitmap(drawable);
        float scale = newHeight / (((float)bitmap.getHeight()));
        return BitmapUtil.bitmapZoomByScale(bitmap, scale, scale);
    }

    /**根据指定的宽度比例值和高度比例值进行缩放*/
    public static Bitmap bitmapZoomByScale(Bitmap srcBitmap, float scaleWidth, float scaleHeight) {
        int width = srcBitmap.getWidth();
        int height = srcBitmap.getHeight();
        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);
        Bitmap bitmap = Bitmap.createBitmap(srcBitmap, 0, 0, width, height, matrix, true);
        if(bitmap != null) {
            return bitmap;
        }else {
            return srcBitmap;
        }
    }

    /**将drawable对象转成bitmap对象*/
    public static Bitmap drawableToBitmap(Drawable drawable) {
        int width = drawable.getIntrinsicWidth();
        int height = drawable.getIntrinsicHeight();
        Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
        Bitmap bitmap = Bitmap.createBitmap(width, height, config);
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, width, height);
        drawable.draw(canvas);
        return bitmap;
    }

    /**将drawable对象转成bitmap对象*/
    public static Bitmap drawableToBitmap2(Drawable drawable) {
        BitmapDrawable bd = (BitmapDrawable) drawable;
        Bitmap bm= bd.getBitmap();
        return bm;
    }
        /**将base64图片对象转成bitmap对象*/
        public static Bitmap base64ToBitmap(String string, int optionSize) {
        Bitmap bitmap = null;
        try {
            byte[] bitmapArray = Base64.decode(string.split(",")[1], Base64.DEFAULT);
            bitmap = byteToBitmap(bitmapArray, optionSize);

        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }
   public static Bitmap byteToBitmap(byte[] imgByte, int optionSize) {
        InputStream input = null;
        Bitmap bitmap = null;
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = optionSize;
        options.inScaled = true;
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        input = new ByteArrayInputStream(imgByte);
        SoftReference softReference = new SoftReference(BitmapFactory.decodeStream(input, null, options));
        bitmap = (Bitmap) softReference.get();
        if (imgByte != null) {
            imgByte = null;
        }
        try {
            if (input != null) {
                input.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        return bitmap;
    }

    /**将bitmap对象保存成图片到sd卡中*/
    public static void saveBitmapToSDCard(Bitmap bitmap, String path) {

        File file = new File(path);
        if(file.exists()) {
            file.delete();
        }
        try {
            FileOutputStream fileOutputStream = new FileOutputStream(file);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, ((OutputStream)fileOutputStream));//设置PNG的话，透明区域不会变成黑色

            fileOutputStream.close();
            System.out.println("----------save success-------------------");
        }
        catch(Exception v0) {
            v0.printStackTrace();
        }

    }
    /**从sd卡中获取图片的bitmap对象*/
    public static Bitmap getBitmapFromSDCard(String path) {

        Bitmap bitmap = null;
        try {
            FileInputStream fileInputStream = new FileInputStream(path);
            if(fileInputStream != null) {
                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inSampleSize = 2; //当图片资源太大的适合，会出现内存溢出。图片宽高都为原来的二分之一，即图片为原来的四分一
                bitmap = BitmapFactory.decodeStream(((InputStream) fileInputStream), null, options);
            }
        } catch(Exception e) {
            return null;
        }

        return bitmap;
    }


}