Java 如何将 Bitmap 对象从一个活动传递到另一个活动

How can I pass a Bitmap object from one activity to another

提问by michael

In my activity, I create a Bitmapobject and then I need to launch another Activity, How can I pass this Bitmapobject from the sub-activity (the one which is going to be launched)?

在我的活动中，我创建了一个Bitmap对象，然后我需要启动另一个对象Activity，如何Bitmap从子活动（将要启动的那个）传递这个对象？

采纳答案by Erich Douglass

Bitmapimplements Parcelable, so you could always pass it with the intent:

Bitmap实现Parcelable，因此您始终可以通过以下意图传递它：

Intent intent = new Intent(this, NewActivity.class);
intent.putExtra("BitmapImage", bitmap);

and retrieve it on the other end:

并在另一端检索它：

Intent intent = getIntent(); 
Bitmap bitmap = (Bitmap) intent.getParcelableExtra("BitmapImage");

回答by Harlo Holmes

Actually, passing a bitmap as a Parcelable will result in a "JAVA BINDER FAILURE" error. Try passing the bitmap as a byte array and building it for display in the next activity.

实际上，将位图作为 Parcelable 传递将导致“JAVA BINDER FAILURE”错误。尝试将位图作为字节数组传递并构建它以在下一个活动中显示。

I shared my solution here:
how do you pass images (bitmaps) between android activities using bundles?

我在这里分享了我的解决方案：
如何使用捆绑包在 android 活动之间传递图像（位图）？

回答by Camino2007

In my case, the way mentioned above didn't worked for me. Every time I put the bitmap in the intent, the 2nd activity didn't start. The same happened when I passed the bitmap as byte[].

就我而言，上述方法对我不起作用。每次我将位图放入意图中时，第二个活动都没有开始。当我将位图作为 byte[] 传递时也发生了同样的情况。

I followed this linkand it worked like a charme and very fast:

我点击了这个链接，它工作得非常好，而且速度非常快：

package your.packagename

import android.graphics.Bitmap;

public class CommonResources { 
      public static Bitmap photoFinishBitmap = null;
}

in my 1st acitiviy:

在我的第一个活动中：

Constants.photoFinishBitmap = photoFinishBitmap;
Intent intent = new Intent(mContext, ImageViewerActivity.class);
startActivity(intent);

and here is the onCreate() of my 2nd Activity:

这是我的第二个活动的 onCreate()：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Bitmap photo = Constants.photoFinishBitmap;
    if (photo != null) {
        mViewHolder.imageViewerImage.setImageDrawable(new BitmapDrawable(getResources(), photo));
    }
}

回答by Illegal Argument

Passsing bitmap as parceable in bundle between activity is not a good idea because of size limitation of Parceable(1mb). You can store the bitmap in a file in internal storage and retrieve the stored bitmap in several activities. Here's some sample code.

由于 Parceable(1mb) 的大小限制，在活动之间的 bundle 中将位图作为 parceable 传递不是一个好主意。您可以将位图存储在内部存储的文件中，并在多个活动中检索存储的位图。这是一些示例代码。

To store bitmap in a file myImagein internal storage:

要将位图存储在内部存储器中的文件myImage中：

public String createImageFromBitmap(Bitmap bitmap) {
    String fileName = "myImage";//no .png or .jpg needed
    try {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        FileOutputStream fo = openFileOutput(fileName, Context.MODE_PRIVATE);
        fo.write(bytes.toByteArray());
        // remember close file output
        fo.close();
    } catch (Exception e) {
        e.printStackTrace();
        fileName = null;
    }
    return fileName;
}

Then in the next activity you can decode this file myImage to a bitmap using following code:

然后在下一个活动中，您可以使用以下代码将此文件 myImage 解码为位图：

//here context can be anything like getActivity() for fragment, this or MainActivity.this
Bitmap bitmap = BitmapFactory.decodeStream(context.openFileInput("myImage"));

NoteA lot of checking for null and scaling bitmap's is ommited.

注意省略了对空值和缩放位图的大量检查。

回答by android developer

If the image is too large and you can't save&load it to the storage, you should consider just using a global static reference to the bitmap (inside the receiving activity), which will be reset to null on onDestory, only if "isChangingConfigurations" returns true.

如果图像太大并且您无法将其保存并加载到存储中，您应该考虑仅使用位图的全局静态引用（在接收活动中），只有在“isChangingConfigurations”时才会在 onDestory 上将其重置为 null返回真。

回答by

Because Intent has size limit . I use public static object to do pass bitmap from service to broadcast ....

因为 Intent 有 size limit 。我使用公共静态对象将位图从服务传递到广播......

public class ImageBox {
    public static Queue<Bitmap> mQ = new LinkedBlockingQueue<Bitmap>(); 
}

pass in my service

传递我的服务

private void downloadFile(final String url){
        mExecutorService.submit(new Runnable() {
            @Override
            public void run() {
                Bitmap b = BitmapFromURL.getBitmapFromURL(url);
                synchronized (this){
                    TaskCount--;
                }
                Intent i = new Intent(ACTION_ON_GET_IMAGE);
                ImageBox.mQ.offer(b);
                sendBroadcast(i);
                if(TaskCount<=0)stopSelf();
            }
        });
    }

My BroadcastReceiver

我的广播接收器

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            LOG.d(TAG, "BroadcastReceiver get broadcast");

            String action = intent.getAction();
            if (DownLoadImageService.ACTION_ON_GET_IMAGE.equals(action)) {
                Bitmap b = ImageBox.mQ.poll();
                if(b==null)return;
                if(mListener!=null)mListener.OnGetImage(b);
            }
        }
    };

回答by Mwangi Njuguna

It might be late but can help. On the first fragment or activity do declare a class...for example

可能会迟到，但可以提供帮助。在第一个片段或活动上声明一个类......例如

   @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        description des = new description();

        if (requestCode == PICK_IMAGE_REQUEST && data != null && data.getData() != null) {
            filePath = data.getData();
            try {
                bitmap = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), filePath);
                imageView.setImageBitmap(bitmap);
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
                constan.photoMap = bitmap;
            } catch (IOException e) {
                e.printStackTrace();
            }
       }
    }

public static class constan {
    public static Bitmap photoMap = null;
    public static String namePass = null;
}

Then on the second class/fragment do this..

然后在第二堂课/片段上做这个..

Bitmap bm = postFragment.constan.photoMap;
final String itemName = postFragment.constan.namePass;

Hope it helps.

希望能帮助到你。

回答by R?mulo Z. C. Cunha

You can create a bitmap transfer. try this....

您可以创建位图传输。尝试这个....

In the first class:

在第一堂课中：

1) Create:

1）创建：

private static Bitmap bitmap_transfer;

2) Create getter and setter

2）创建getter和setter

public static Bitmap getBitmap_transfer() {
    return bitmap_transfer;
}

public static void setBitmap_transfer(Bitmap bitmap_transfer_param) {
    bitmap_transfer = bitmap_transfer_param;
}

3) Set the image:

3）设置图像：

ImageView image = (ImageView) view.findViewById(R.id.image);
image.buildDrawingCache();
setBitmap_transfer(image.getDrawingCache());

Then, in the second class:

然后，在第二个类中：

ImageView image2 = (ImageView) view.findViewById(R.id.img2);
imagem2.setImageDrawable(new BitmapDrawable(getResources(), classe1.getBitmap_transfer()));

回答by Ali Tamoor

All of the above solutions doesn't work for me, Sending bitmap as parceableByteArrayalso generates error android.os.TransactionTooLargeException: data parcel size.

以上所有解决方案对我都不起作用，发送位图parceableByteArray也会产生错误android.os.TransactionTooLargeException: data parcel size。

Solution

解决方案

1. Saved the bitmap in internal storage as:

1. 将内部存储中的位图保存为：

public String saveBitmap(Bitmap bitmap) {
        String fileName = "ImageName";//no .png or .jpg needed
        try {
            ByteArrayOutputStream bytes = new ByteArrayOutputStream();
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
            FileOutputStream fo = openFileOutput(fileName, Context.MODE_PRIVATE);
            fo.write(bytes.toByteArray());
            // remember close file output
            fo.close();
        } catch (Exception e) {
            e.printStackTrace();
            fileName = null;
        }
        return fileName;
    }

1. and send in putExtra(String)as

2. 并putExtra(String)作为

Intent intent = new Intent(ActivitySketcher.this,ActivityEditor.class);
intent.putExtra("KEY", saveBitmap(bmp));
startActivity(intent);

1. and Receive it in other activity as:

3. 并在其他活动中将其接收为：

if(getIntent() != null){
  try {
           src = BitmapFactory.decodeStream(openFileInput("myImage"));
       } catch (FileNotFoundException e) {
            e.printStackTrace();
      }

 }

回答by Adam Hurwitz

Compress and Send Bitmap

压缩并发送 Bitmap

The accepted answer will crash when the Bitmapis too large.I believe it's a 1MBlimit. The Bitmapmust be compressed into a different file format such as a JPGrepresented by a ByteArray, then it can be safely passed via an Intent.

当Bitmap太大时，接受的答案将崩溃。我相信这是一个1MB 的限制。在Bitmap必须被压缩到不同的文件格式，诸如JPG由a表示ByteArray，那么它可以安全地通过传递Intent。

Implementation

执行

The function is contained in a separate thread using Kotlin Coroutinesbecause the Bitmapcompression is chained after the Bitmapis created from an url String. The Bitmapcreation requires a separate thread in order to avoid Application Not Responding (ANR)errors.

该函数包含在使用Kotlin 协程的单独线程中，因为Bitmap压缩Bitmap是在从 url 创建之后链接的String。在Bitmap创建要求，以避免一个单独的线程应用程序无响应（ANR）错误。

Concepts Used

使用的概念

• Kotlin Coroutinesnotes.
• The Loading, Content, Error (LCE)pattern is used below. If interested you can learn more about it in this talk and video.
• LiveDatais used to return the data. I've compiled my favorite LiveDataresource in these notes.
• In Step 3, toBitmap()is a Kotlin extension functionrequiring that library to be added to the app dependencies.

• Kotlin 协程注释。
• 下面使用了加载、内容、错误 (LCE)模式。如果有兴趣，您可以在此演讲和视频中了解更多信息。
• LiveData用于返回数据。我在这些笔记中编译了我最喜欢的LiveData资源。
• 在第 3 步中，toBitmap()是一个Kotlin 扩展函数，要求将该库添加到应用程序依赖项中。

Code

代码

1. Compress Bitmapto JPGByteArrayafter it has been created.

1.创建好后压缩Bitmap成JPGByteArray。

Repository.kt

存储库.kt

suspend fun bitmapToByteArray(url: String) = withContext(Dispatchers.IO) {
    MutableLiveData<Lce<ContentResult.ContentBitmap>>().apply {
        postValue(Lce.Loading())
        postValue(Lce.Content(ContentResult.ContentBitmap(
            ByteArrayOutputStream().apply {
                try {                     
                    BitmapFactory.decodeStream(URL(url).openConnection().apply {
                        doInput = true
                        connect()
                    }.getInputStream())
                } catch (e: IOException) {
                   postValue(Lce.Error(ContentResult.ContentBitmap(ByteArray(0), "bitmapToByteArray error or null - ${e.localizedMessage}")))
                   null
                }?.compress(CompressFormat.JPEG, BITMAP_COMPRESSION_QUALITY, this)
           }.toByteArray(), "")))
        }
    }

ViewModel.kt

视图模型.kt

//Calls bitmapToByteArray from the Repository
private fun bitmapToByteArray(url: String) = liveData {
    emitSource(switchMap(repository.bitmapToByteArray(url)) { lce ->
        when (lce) {
            is Lce.Loading -> liveData {}
            is Lce.Content -> liveData {
                emit(Event(ContentResult.ContentBitmap(lce.packet.image, lce.packet.errorMessage)))
            }
            is Lce.Error -> liveData {
                Crashlytics.log(Log.WARN, LOG_TAG,
                        "bitmapToByteArray error or null - ${lce.packet.errorMessage}")
            }
        }
    })
}

2. Pass image as ByteArrayvia an Intent.

2.ByteArray通过Intent.

In this sample it's passed from a Fragmentto a Service. It's the same concept if being shared between two Activities.

在此示例中，它从Fragment传递到Service。如果在两个活动之间共享，则是相同的概念。

Fragment.kt

片段.kt

ContextCompat.startForegroundService(
    context!!,
    Intent(context, AudioService::class.java).apply {
        action = CONTENT_SELECTED_ACTION
        putExtra(CONTENT_SELECTED_BITMAP_KEY, contentPlayer.image)
    })

3. Convert ByteArrayback to Bitmap.

3. 转换ByteArray回Bitmap.

Utils.kt

实用工具.kt

fun ByteArray.byteArrayToBitmap(context: Context) =
    run {
        BitmapFactory.decodeByteArray(this, BITMAP_OFFSET, size).run {
            if (this != null) this
            // In case the Bitmap loaded was empty or there is an error I have a default Bitmap to return.
            else AppCompatResources.getDrawable(context, ic_coinverse_48dp)?.toBitmap()
        }
    }