Android 如何在 Glide 中显示数据库图像？

Question

我的申请中有一个 SqliteDatabase。在这个数据库中，我保存了 Sting 和 Blob（用于保存图像）。此图像以 byte[ ] 保存在应用程序中。我借助以下代码将此图像转换为位图：

    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库中显示这张图片，我写了下面的代码：

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

但是，当我运行应用程序时，显示以下错误：

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

如何修复它并在 Glide 库中显示位图？谢谢大家

Answer 1

使用以下方法将图像转换为字节数组并作为 BLOB 存储到数据库中

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);
    }

当您想使用 Glide 显示到图像视图时，请使用以下内容

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);
    }

从数据库存储和检索图像的简单示例

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) {
    }
}

希望对你有用

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