在Android中从内存中保存和读取位图/图像

What I want to do, is to save an image to the internal memory of the phone (Not The SD Card).

我想做的是将图像保存到手机的内存中(而不是SD卡)。

How can I do it?

我怎么做呢?

I have got the image directly from the camera to the image view in my app its all working fine.

我已经把图像直接从相机上传到我的app里的图像视图，一切正常。

Now what I want is to save this image from Image View to the Internal memory of my android device and also access it when required.

现在我想要的是将这个图像从图像视图保存到我的安卓设备的内存中，并在需要的时候访问它。

Can anyone please guide me how to do this?

谁能告诉我怎么做这件事吗?

I am a little new to android so please, I would appreciate if I can have a detailed procedure.

我是android的新手，希望能给我一个详细的流程。

4 个解决方案

#1

Use the below code to save the image to internal directory.

使用下面的代码将映像保存到内部目录。

private String saveToInternalStorage(Bitmap bitmapImage){
        ContextWrapper cw = new ContextWrapper(getApplicationContext());
         // path to /data/data/yourapp/app_data/imageDir
        File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
        // Create imageDir
        File mypath=new File(directory,"profile.jpg");

        FileOutputStream fos = null;
        try {           
            fos = new FileOutputStream(mypath);
       // Use the compress method on the BitMap object to write image to the OutputStream
            bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
        } catch (Exception e) {
              e.printStackTrace();
        } finally {
            try {
              fos.close();
            } catch (IOException e) {
              e.printStackTrace();
            }
        } 
        return directory.getAbsolutePath();
    }

Explanation :

解释:

1.The Directory will be created with the given name. Javadocs is for to tell where exactly it will create the directory.

1。该目录将使用给定的名称创建。Javadocs是用来告诉创建目录的确切位置的。

2.You will have to give the image name by which you want to save it.

2。您必须提供要保存它的图像名称。

To Read the file from internal memory. Use below code

从内存中读取文件。使用下面的代码

private void loadImageFromStorage(String path)
{

    try {
        File f=new File(path, "profile.jpg");
        Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
            ImageView img=(ImageView)findViewById(R.id.imgPicker);
        img.setImageBitmap(b);
    } 
    catch (FileNotFoundException e) 
    {
        e.printStackTrace();
    }

}

#2

/**
 * Created by Ilya Gazman on 3/6/2016.
 */
public class ImageSaver {

    private String directoryName = "images";
    private String fileName = "image.png";
    private Context context;
    private boolean external;

    public ImageSaver(Context context) {
        this.context = context;
    }

    public ImageSaver setFileName(String fileName) {
        this.fileName = fileName;
        return this;
    }

    public ImageSaver setExternal(boolean external) {
        this.external = external;
        return this;
    }

    public ImageSaver setDirectoryName(String directoryName) {
        this.directoryName = directoryName;
        return this;
    }

    public void save(Bitmap bitmapImage) {
        FileOutputStream fileOutputStream = null;
        try {
            fileOutputStream = new FileOutputStream(createFile());
            bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (fileOutputStream != null) {
                    fileOutputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @NonNull
    private File createFile() {
        File directory;
        if(external){
            directory = getAlbumStorageDir(directoryName);
        }
        else {
            directory = context.getDir(directoryName, Context.MODE_PRIVATE);
        }
        if(!directory.exists() && !directory.mkdirs()){
            Log.e("ImageSaver","Error creating directory " + directory);
        }

        return new File(directory, fileName);
    }

    private File getAlbumStorageDir(String albumName) {
        return new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES), albumName);
    }

    public static boolean isExternalStorageWritable() {
        String state = Environment.getExternalStorageState();
        return Environment.MEDIA_MOUNTED.equals(state);
    }

    public static boolean isExternalStorageReadable() {
        String state = Environment.getExternalStorageState();
        return Environment.MEDIA_MOUNTED.equals(state) ||
                Environment.MEDIA_MOUNTED_READ_ONLY.equals(state);
    }

    public Bitmap load() {
        FileInputStream inputStream = null;
        try {
            inputStream = new FileInputStream(createFile());
            return BitmapFactory.decodeStream(inputStream);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}

Usage

• To save:

  保存:

  new ImageSaver(context).
          setFileName("myImage.png").
          setDirectoryName("images").
          save(bitmap);
  

• To load:

  加载:

  Bitmap bitmap = new ImageSaver(context).
          setFileName("myImage.png").
          setDirectoryName("images").
          load();
  

Edit:

编辑:

Added ImageSaver.setExternal(boolean) to support saving to external storage based on googles example.

添加了ImageSaver.setExternal(布尔)以支持基于googles示例的外部存储保存。

#3

Came across this question today and this is how I do it. Just call this function with the required parameters

今天遇到了这个问题，这就是我怎么做的。只需使用所需的参数调用这个函数

public void saveImage(Context context, Bitmap bitmap, String name, String extension){
    name = name + "." + extension;
    FileOutputStream fileOutputStream;
    try {
        fileOutputStream = context.openFileOutput(name, Context.MODE_PRIVATE);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        fileOutputStream.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Similarly, for reading the same, use this

类似地，对于相同的阅读，请使用这个

public Bitmap loadImageBitmap(Context context,String name,String extension){
    name = name + "." + extension
    FileInputStream fileInputStream
    Bitmap bitmap = null;
    try{
        fileInputStream = context.openFileInput(name);
        bitmap = BitmapFactory.decodeStream(fileInputStream);
        fileInputStream.close();
    } catch(Exception e) {
        e.printStackTrace();
    }
     return bitmap;
}

#4

you will convert the image to bytes ... and then you can store it into database , and when you wont to use this pic , you will re-converte it from byte ,,, find about how to convert image to bytes ....

你将把图像转换成字节……然后你可以将它存储到数据库中,当你习惯于使用这个图片,你会从字节,re-converte,找到如何将图像转换为字节....