从图库中获取并上传时，ImageView 上的图像方向已更改

Question

我只想从图库中获取图像并上传然后从服务器下载并将其设置在 Activity 的 ImageView 上。 图像视图放置在活动的中心。 一切正常，只是一个 screenOrientation 变化问题，在从服务器获取图像后调整 ImageView 上的图像，下载并设置为图像视图。 请查看我用来从服务器下载图像位图并将其设置为所需的 ImageView 的代码。 在从图库或相机拍摄人像图像的情况下，它通常显示旋转图像。 如果我的代码中缺少任何内容，请告诉我。

package com.fedorvlasov.lazylist;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import com.example.qlique.R;
import android.os.Handler;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

public class ImageLoader {
    MemoryCache memoryCache = new MemoryCache();
    FileCache fileCache;
    private Map<ImageView, String> imageViews = Collections
            .synchronizedMap(new WeakHashMap<ImageView, String>());
    ExecutorService executorService;
    Handler handler = new Handler();// handler to display images in UI thread

    public ImageLoader(Context context) {
        fileCache = new FileCache(context);
        executorService = Executors.newFixedThreadPool(5);
    }

    final int stub_id = R.drawable.stub;

    public void DisplayImage(String url, ImageView imageView) {
        imageViews.put(imageView, url);
        Bitmap bitmap = memoryCache.get(url);
        if (bitmap != null)
            imageView.setImageBitmap(bitmap);
        else {
            queuePhoto(url, imageView);
            imageView.setImageResource(stub_id);
        }
    }

    private void queuePhoto(String url, ImageView imageView) {
        PhotoToLoad p = new PhotoToLoad(url, imageView);
        executorService.submit(new PhotosLoader(p));
    }

    private Bitmap getBitmap(String url) {
        File f = fileCache.getFile(url);

        // from SD cache
        Bitmap b = decodeFile(f);
        if (b != null)
            return b;

        // from web
        try {
            Bitmap bitmap = null;
            URL imageUrl = new URL(url);
            HttpURLConnection conn = (HttpURLConnection) imageUrl
                    .openConnection();
            conn.setConnectTimeout(30000);
            conn.setReadTimeout(30000);
            conn.setInstanceFollowRedirects(true);
            InputStream is = conn.getInputStream();
            OutputStream os = new FileOutputStream(f);
            Utils.CopyStream(is, os);
            os.close();
            conn.disconnect();
            bitmap = decodeFile(f);
            return bitmap;
        } catch (Throwable ex) {
            ex.printStackTrace();
            if (ex instanceof OutOfMemoryError)
                memoryCache.clear();
            return null;
        }
    }

    // decodes image and scales it to reduce memory consumption
    private Bitmap decodeFile(File f) {
        try {
            // decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            FileInputStream stream1 = new FileInputStream(f);
            BitmapFactory.decodeStream(stream1, null, o);
            stream1.close();

            // Find the correct scale value. It should be the power of 2.
            final int REQUIRED_SIZE = 70;
            int width_tmp = o.outWidth, height_tmp = o.outHeight;
            int scale = 1;
            while (true) {
                if (width_tmp / 2 < REQUIRED_SIZE
                        || height_tmp / 2 < REQUIRED_SIZE)
                    break;
                width_tmp /= 2;
                height_tmp /= 2;
                scale *= 2;
            }

            // decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            FileInputStream stream2 = new FileInputStream(f);
            Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
            stream2.close();
            return bitmap;
        } catch (FileNotFoundException e) {
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    // Task for the queue
    private class PhotoToLoad {
        public String url;
        public ImageView imageView;

        public PhotoToLoad(String u, ImageView i) {
            url = u;
            imageView = i;
        }
    }

    class PhotosLoader implements Runnable {
        PhotoToLoad photoToLoad;

        PhotosLoader(PhotoToLoad photoToLoad) {
            this.photoToLoad = photoToLoad;
        }

        @Override
        public void run() {
            try {
                if (imageViewReused(photoToLoad))
                    return;
                Bitmap bmp = getBitmap(photoToLoad.url);
                memoryCache.put(photoToLoad.url, bmp);
                if (imageViewReused(photoToLoad))
                    return;
                BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
                handler.post(bd);
            } catch (Throwable th) {
                th.printStackTrace();
            }
        }
    }

    boolean imageViewReused(PhotoToLoad photoToLoad) {
        String tag = imageViews.get(photoToLoad.imageView);
        if (tag == null || !tag.equals(photoToLoad.url))
            return true;
        return false;
    }

    // Used to display bitmap in the UI thread
    class BitmapDisplayer implements Runnable {
        Bitmap bitmap;
        PhotoToLoad photoToLoad;

        public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
            bitmap = b;
            photoToLoad = p;
        }

        public void run() {
            if (imageViewReused(photoToLoad))
                return;
            if (bitmap != null)
                photoToLoad.imageView.setImageBitmap(bitmap);
            else
                photoToLoad.imageView.setImageResource(stub_id);
        }
    }

    public void clearCache() {
        memoryCache.clear();
        fileCache.clear();
    }
}

Answer 1

首先检查图像的Orientation

public static int getExifOrientation(String filepath) {
                int degree = 0;
                ExifInterface exif = null;
                try {
                        exif = new ExifInterface(filepath);
                } catch (IOException ex) {
                        ex.printStackTrace();
                }
                if (exif != null) {
                        int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1);
                        if (orientation != -1) {
                                // We only recognise a subset of orientation tag values.
                                switch (orientation) {
                                case ExifInterface.ORIENTATION_ROTATE_90:
                                        degree = 90;
                                        break;
                                case ExifInterface.ORIENTATION_ROTATE_180:
                                        degree = 180;
                                        break;
                                case ExifInterface.ORIENTATION_ROTATE_270:
                                        degree = 270;
                                        break;
                                }

                        }
                }

                return degree;
        }

并将 Bitmap 的角度旋转到该度数。

Bitmap bitmap = YOUR_BITMAP;
    //rotate bitmap
    Matrix matrix = new Matrix();               
    matrix.postRotate(orientation);
    //create new rotated bitmap
    bitmap = Bitmap.createBitmap(bitmap, 0, 0,bitmap.getWidth(), bitmap.getHeight(), matrix, true);  
   YOUR_IMAGE_VIEW.setImageBitmap(bitmap);

Answer 2

一个不错的在线工具，用于查看方向和详细信息 EXIF 信息http://metapicz.com/#exif-box 。

如果您可以在服务器端修复/重置方向（每个图像一次），或者在客户端修复有点昂贵（因为这种转换每次都会发生），那就太好了