file转bitmap

File param = new File();

Bitmap bitmap= BitmapFactory.decodeFile(param.getPath(）);

drawable转bitmap

Bitmap    bmp = BitmapFactory.decodeResource(getResources(),R.mipmap.jcss_03 );

url转bitmap

Bitmap bitmap;
public Bitmap returnBitMap(final String url){

    new Thread(new Runnable() {
        @Override
        public void run() {
            URL imageurl = null;

            try {
                imageurl = new URL(url);
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }
            try {
                HttpURLConnection conn = (HttpURLConnection)imageurl.openConnection();
                conn.setDoInput(true);
                conn.connect();
                InputStream is = conn.getInputStream();
                bitmap = BitmapFactory.decodeStream(is);
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    return bitmap;
}

方法二：

public Bitmap getBitmap(String url) {
    Bitmap bm = null;
    try {
        URL iconUrl = new URL(url);
        URLConnection conn = iconUrl.openConnection();
        HttpURLConnection http = (HttpURLConnection) conn;

        int length = http.getContentLength();

        conn.connect();
        // 获得图像的字符流
        InputStream is = conn.getInputStream();
        BufferedInputStream bis = new BufferedInputStream(is, length);
        bm = BitmapFactory.decodeStream(bis);
        bis.close();
        is.close();// 关闭流
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    return bm;
}

可配合前台线程显示

private Handler mHandler = new Handler() {
    public void handleMessage(android.os.Message msg) {
        switch (msg.what) {
            case REFRESH_COMPLETE:
                myheadimage.setImageBitmap(bitmap);//显示
                break;
        }
    }
};

String imageUrl = "http://www.pp3.cn/uploads/201511/2015111212.jpg";
bitmap= returnBitMap(imageUrl);
mHandler.sendEmptyMessageDelayed(REFRESH_COMPLETE, 1000);

bitmap转file

private  String SAVE_PIC_PATH = Environment.getExternalStorageState().equalsIgnoreCase(Environment.MEDIA_MOUNTED)
        ? Environment.getExternalStorageDirectory().getAbsolutePath() : "/mnt/sdcard";//

private  String SAVE_REAL_PATH = SAVE_PIC_PATH + "/good/savePic";//保存的确

saveFile(bmp, System.currentTimeMillis() + ".png");

  //保存方法
    private void saveFile(Bitmap bm, String fileName) throws IOException {
        String subForder = SAVE_REAL_PATH;
        File foder = new File(subForder);
        if (!foder.exists()) foder.mkdirs();

        File myCaptureFile = new File(subForder, fileName);
        Log.e("lgq","图片保持。。。。wwww。。。。"+myCaptureFile);
        ends = myCaptureFile.getPath();
        if (!myCaptureFile.exists()) myCaptureFile.createNewFile();
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
        bm.compress(Bitmap.CompressFormat.JPEG, 100, bos);
        bos.flush();
        bos.close();
//        ToastUtil.showSuccess(getApplicationContext(), "已保存在/good/savePic目录下", Toast.LENGTH_SHORT);
        //发送广播通知系统
        Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
        Uri uri = Uri.fromFile(myCaptureFile);
        intent.setData(uri);
        this.sendBroadcast(intent);
    }

    if(mbitmap != null){
        if(Build.VERSION.SDK_INT > Build.VERSION_CODES.Q){
            saveImage29(mbitmap);
        }else{
            if ( saveImage(file, mbitmap)){
                LgqLogPlus.e("路径---3-- "+file);
                //发送广播通知系统
                Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
                Uri uri = Uri.fromFile(new File(file));
                intent.setData(uri);
                this.sendBroadcast(intent);


            }
        }
    }

    /**
     * API29 中的最新保存图片到相册的方法
     */
    private void saveImage29(Bitmap toBitmap) {
        //开始一个新的进程执行保存图片的操作
        Uri insertUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new ContentValues());
        //使用use可以自动关闭流
        try {
            OutputStream outputStream = getContentResolver().openOutputStream(insertUri, "rw");
            if (toBitmap.compress(Bitmap.CompressFormat.JPEG, 90, outputStream)) {
                Log.e("保存成功", "success");
            } else {
                Log.e("保存失败", "fail");
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    //统一方法将图片Bitmap保存在文件中
    public static boolean saveImageToFile(Context mContext,String fileName, Bitmap frame) {
        if (fileName == null || fileName.length() <= 0)
            return false;
        if (frame == null || frame.getByteCount() <= 0)
            return false;

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        frame.compress(Bitmap.CompressFormat.JPEG, 100, baos);//质量压缩方法，这里100表示不压缩，把压缩后的数据存放到baos中
        int options = 100;
        while (baos.toByteArray().length / 1024 > 100) {  //循环判断如果压缩后图片是否大于100kb,大于继续压缩
            baos.reset();//重置baos即清空baos
            //第一个参数 ：图片格式 ，第二个参数： 图片质量，100为最高，0为最差  ，第三个参数：保存压缩后的数据的流
            frame.compress(Bitmap.CompressFormat.JPEG, options, baos);//这里压缩options%，把压缩后的数据存放到baos中
            options -= 10;//每次都减少10
        }
        ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());//把压缩后的数据baos存放到ByteArrayInputStream中
        Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);//把ByteArrayInputStream数据生成图片

        if(bitmap!=null){
//            AppLog.Loge("压缩后图片大小为："+bitmap.getByteCount() + "---路径："+fileName);
            saveBitmap(bitmap,fileName);

        }
        return true;
    }


    public static void saveBitmap(Bitmap bitmap,String path) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                String savePath;
                File filePic;
                if (Environment.getExternalStorageState().equals(
                        Environment.MEDIA_MOUNTED)) {
                    savePath = path;
                } else {
//                    AppLog.Loge( "saveBitmap failure : sdcard not mounted");
                    return;
                }
                try {
                    filePic = new File(savePath);
                    if (!filePic.exists()) {
                        filePic.getParentFile().mkdirs();
                        filePic.createNewFile();
                    }
                    FileOutputStream fos = new FileOutputStream(filePic);
                    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
                    fos.flush();
                    fos.close();
                } catch (IOException e) {
//                    AppLog.Loge( "保存图片失败 saveBitmap: " + e.getMessage());
                    return;
                }
//                AppLog.Loge( "saveBitmap success: " + filePic.getAbsolutePath());
            }
        }).start();

    }

 Uri转Bitmap

public static Bitmap decodeUri(Context context, Uri uri, int maxWidth, int maxHeight) {
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true; //只读取图片尺寸
    readBitmapScale(context, uri, options);

    //计算实际缩放比例
    int scale = 1;
    for (int i = 0; i < Integer.MAX_VALUE; i++) {
        if ((options.outWidth / scale > maxWidth &&
                options.outWidth / scale > maxWidth * 1.4) ||
                (options.outHeight / scale > maxHeight &&
                        options.outHeight / scale > maxHeight * 1.4)) {
            scale++;
        } else {
            break;
        }
    }

    options.inSampleSize = scale;
    options.inJustDecodeBounds = false;//读取图片内容
    options.inPreferredConfig = Bitmap.Config.RGB_565; //根据情况进行修改
    Bitmap bitmap = null;
    try {
        bitmap = readBitmapData(context, uri, options);
    } catch (Throwable e) {
        e.printStackTrace();
    }
    return bitmap;
}

bitmap与byte[]之间相互转换

Android 图片压缩，bitmap与byte[]之间相互转换，Bitmap转String：Android 图片压缩，Bitmap旋转，bitmap与byte[]之间相互转换，Bitmap与String互转_meixi_android的博客-CSDN博客_android mipmap转bitmap

 bug在线交流：扣Q   1085220040