安卓 : width and height must be > 0 for recycler view when Converting to Bitmap

Question

在 Sqlite 中存储文本和图像，并尝试将这些数据检索到 recyclerview 中，当将图像显示到 recyclerview 中时，它显示错误宽度和高度必须 > 0

在 sqlite 中保存图像时，我将位图转换为字节

数据库助手

String query =
                "CREATE TABLE IF NOT EXISTS " + TABLE_NAME + "("
                        + COLUMN_ID + " INTEGER PRIMARY KEY ,"
                        + COLUMN_TITLE + " TEXT, "
                        + COLUMN_IMAGE + " BLOB )";

        sqLiteDatabase.execSQL(query);

CustumAdapter.java

 private LayoutInflater mInflater;
private ArrayList<String> list_name;
ArrayList<byte[]> list_image ;



public CustomAdapter( Context context
          , ArrayList list_name, ArrayList list_image ){
    mInflater = LayoutInflater.from(context);
    this.list_name = list_name;
    this.list_image =list_image ;

}
@Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {

        holder.listname.setText(String.valueOf(list_name.get(position)));
       Bitmap bmp = BitmapFactory.decodeByteArray(list_image. get (position), 0, list_image. get (position).length);

   ImageView  image = holder.imgname;
   image.setImageBitmap(Bitmap.createScaledBitmap(bmp, image.getWidth(), image.getHeight(), false));
    }

    @Override
    public int getItemCount() {
        return list_name.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {

        TextView listname;
        ImageView imgname;

        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            listname = itemView.findViewById(R.id.list_name);

           imgname = itemView.findViewById(R.id.image_list);

        }
    }

MainActivity.java

public class MainActivity extends AppCompatActivity {

   
    DatabaseHelper myDB;
    ArrayList<String>  title;
    ArrayList<byte[]> image;
    CustomAdapter ca;

          myDB = new DatabaseHelper(MainActivity.this);
        
                title = new ArrayList<>();
                image = new ArrayList<byte[]>();
        
                storeDataInArrays();
                ca = new CustomAdapter(MainActivity.this, title,image);
                recyclerView.setAdapter(ca);

    
     void storeDataInArrays(){
            Cursor cursor = myDB.readAllData();
            if(cursor.getCount() == 0){
    
                Toast.makeText(this, "No Data.", Toast.LENGTH_SHORT).show();
   
            }else{
                while (cursor.moveToNext()){
    
                    title.add(cursor.getString(1));
                    image.add(cursor.getBlob(2));
    
                }
               
            }
        }

RecyclerView.xml

<androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycle"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/toolbar"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        android:layout_marginBottom="50dp"
        />

日志猫

 java.lang.IllegalArgumentException: width and height must be > 0
        at android.graphics.Bitmap.createBitmap(Bitmap.java:1055)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:1022)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:972)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:892)
        at android.graphics.Bitmap.createScaledBitmap(Bitmap.java:763)
        at com.Karthickyuvan.check.CustomAdapter.onBindViewHolder(CustomAdapter.java:61)
        at com.Karthickyuvan.check.CustomAdapter.onBindViewHolder(CustomAdapter.java:19)

Answer 1

在 onBindViewHolder 方法中，您错误地将 byte[] 转换为 Integer。

您可以使用 BitmapFactory.decodeByteArray() 执行从 byte[] 到位图的解码。

Bitmap bmp = BitmapFactory.decodeByteArray(list_image. get (position), 0, list_image. get (position). length);  

然后使用ImageView.setImageBitmap()

image = holder.imgname;
image.setImageBitmap(bmp);