如何在Android上的Glide中显示数据库图像？

Question

我的应用程序中有一个SqliteDatabase。在此数据库中，我保存Sting和Blob（用于保存图像）。该图像保存在byte []的应用程序中。我转换这个图像与下面的代码的帮助下，位图：

byte[] Recycler_imageByte; 
    Bitmap Recycler_theImage; 

holder.Recycler_imageByte = data.get(position).getKey_image(); 
ByteArrayInputStream imageStream = new ByteArrayInputStream(holder.Recycler_imageByte); 
holder.Recycler_theImage = BitmapFactory.decodeStream(imageStream); 

我想在Glide libary显示此图像，我写了下面的代码：

Glide.with(context).load(holder.Recycler_theImage).asBitmap().into(holder.Recycler_adapter_image); 

但是，当我运行的应用程序，出现以下错误：

03-15 10:23:14.311 22440-22440/com.tellfa.dastanak E/AndroidRuntime: FATAL EXCEPTION: main 
Process: com.tellfa.dastanak, PID: 22440 
java.lang.IllegalArgumentException: Unknown type class android.graphics.Bitmap. You must provide a Model of a type for which there is a registered ModelLoader, if you are using a custom model, you must first call Glide#register with a ModelLoaderFactory for your custom model class 
at com.bumptech.glide.RequestManager.loadGeneric(RequestManager.java:629) 
at com.bumptech.glide.RequestManager.load(RequestManager.java:598) 
at com.tellfa.dastanak.Adapters.fragment_RecyclerAdapter.onBindViewHolder(fragment_RecyclerAdapter.java:54) 
at com.tellfa.dastanak.Adapters.fragment_RecyclerAdapter.onBindViewHolder(fragment_RecyclerAdapter.java:27) 
at jp.wasabeef.recyclerview.adapters.AnimationAdapter.onBindViewHolder(AnimationAdapter.java:55) 
at jp.wasabeef.recyclerview.adapters.AnimationAdapter.onBindViewHolder(AnimationAdapter.java:55) 
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5217) 
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5250) 
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4487) 
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4363) 
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1961) 
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1370) 
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1333) 
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:562) 
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2900) 
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3071) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:584) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1077) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573) 
at android.widget.FrameLayout.onLayout(FrameLayout.java:508) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1077) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1627) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.support.design.widget.CoordinatorLayout.layoutChild(CoordinatorLayout.java:1037) 
at android.support.design.widget.CoordinatorLayout.onLayoutChild(CoordinatorLayout.java:747) 
at android.support.design.widget.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:42) 
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1156) 
at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:760) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:1043) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573) 
at android.widget.FrameLayout.onLayout(FrameLayout.java:508) 
at android.view.View.layout(View.java:15654) 
at android.view.ViewGroup.layout(ViewGroup.java:4969) 
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1705) 
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1559) 
at android.widget.LinearLayout.onLayout(LinearLayout.java:1468) 
at android.view.View.layout(Vi 

我该如何解决这个问题并在Glide库中显示位图？谢谢大家。

Answer 1

使用以下为字节数组方法转换图像，并存储到数据库中的BLOB

public String bitmapToString(Bitmap bmp) { 
     ByteArrayOutputStream os = new ByteArrayOutputStream(); 
     bmp.compress(Bitmap.CompressFormat.JPEG, 100, os); 
     byte[] bytes = os.toByteArray(); 
     return Base64.encodeToString(bytes, Base64.DEFAULT); 
    } 

而当你想显示成图像视图中使用滑翔使用以下

public void stringToBitmap(String str) { 
     byte[] bytesImage = Base64.decode(str, Base64.DEFAULT); 
     //Bitmap bitmap = BitmapFactory.decodeByteArray(bytesImage, 0, bytesImage.length); 
     //ivImage.setImageBitmap(bitmap); 
     // using glide 
     Glide.with(this).load(bytesImage).asBitmap().into(ivImage); 
    } 

存储的简单例子并从数据库检索图像

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical"> 

    <Button 
     android:id="@+id/btnInsert" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_centerHorizontal="true" 
     android:text="Insert into DB" /> 

    <Button 
     android:id="@+id/btnView" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_centerHorizontal="true" 
     android:text="View from DB" /> 

    <ImageView 
     android:id="@+id/ivImage" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_centerHorizontal="true" /> 
</LinearLayout> 

MainActivity.java

public class MainActivity extends AppCompatActivity { 

    private DatabaseHelper databaseHelper; 
    private SQLiteDatabase db; 
    private Button btnInsert, btnView; 
    private ImageView ivImage; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     databaseHelper = new DatabaseHelper(this); 
     db = databaseHelper.getWritableDatabase(); 

     ivImage = (ImageView) findViewById(R.id.ivImage); 
     btnInsert = (Button) findViewById(R.id.btnInsert); 
     btnView = (Button) findViewById(R.id.btnView); 


     btnInsert.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       insertImage(); 
      } 
     }); 

     btnView.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       viewFromDb(); 
      } 
     }); 

    } 

    private void insertImage() { 
     Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher); 
     ContentValues values = new ContentValues(); 
     values.put("image", bitmapToString(bmp)); 
     db.insert("table_image", null, values); 
     Toast.makeText(this, "Insert Successful",Toast.LENGTH_SHORT).show(); 
    } 

    private void viewFromDb() { 
     String sql = "select * from table_image"; 
     ArrayList<String> images = new ArrayList<>(); 
     Cursor cursor = db.rawQuery(sql, null); 
     if (cursor != null) { 
      cursor.moveToFirst(); 
      while (!cursor.isAfterLast()) { 
       String img = cursor.getString(cursor.getColumnIndex("image")); 
       images.add(img); 
       cursor.moveToNext(); 
      } 
     } 
     cursor.close(); 
     if (images.size() > 0) { 
      // get last image 
      stringToBitmap(images.get(images.size()-1)); 
     } 
    } 


    public String bitmapToString(Bitmap bmp) { 
     ByteArrayOutputStream os = new ByteArrayOutputStream(); 
     bmp.compress(Bitmap.CompressFormat.PNG, 100, os); 
     byte[] bytes = os.toByteArray(); 
     //return Base64.encodeToString(bytes, Base64.DEFAULT); 
     return Base64.encodeToString(bytes, Base64.DEFAULT); 
    } 

    public void stringToBitmap(String str) { 
     byte[] bytesImage = Base64.decode(str, Base64.DEFAULT); 
     Bitmap bitmap = BitmapFactory.decodeByteArray(bytesImage, 0, bytesImage.length); 
     ivImage.setImageBitmap(bitmap); 
     //Glide.with(this).load(bytesImage).asBitmap().into(ivImage); 
    } 
} 

DatabaseHelper.java

public class DatabaseHelper extends SQLiteOpenHelper { 

    private static final String TAG = "DatabaseHelper"; 

    public static String DB_PATH; 
    public static String DB_NAME = "mdb"; 

    private static SQLiteDatabase myDataBase; 
    private static DatabaseHelper helperInstance; 
    private final Context myContext; 

    public DatabaseHelper(Context context) { 
     super(context, DB_NAME, null, 1); 
     this.myContext = context; 
     DB_PATH = "/data/data/" + myContext.getPackageName() + "/databases/"; 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     Log.e(TAG, "On Create"); 
     String sql = "CREATE TABLE IF NOT EXISTS table_image (_id INTEGER PRIMARY KEY AUTOINCREMENT, image BLOB)"; 
     db.execSQL(sql); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    } 
} 

我希望这是有用的给你。