无法从 SQLite 检索图像。 SKImageDecoder::Factory 返回空值

Question

目前我正在开发一个涉及从 SQLite 捕获、保存和检索图像的应用程序。我设法捕获图像并将其保存到 SQLite 中。但是，我无法取回图像。在将图像保存在 SQLite 中之前，我已将图像转换为字节数组。这是我的编码：

Database.java

public String displayImageBendaOne(String rowId){
    SQLiteDatabase db=helper.getReadableDatabase();

    Cursor cursor = db.query(true, BacaHelper.TABLE_NAME_BENDA, new String[] {BacaHelper.UID,
                    BacaHelper.BENDA, BacaHelper.BENDA_IMAGE, BacaHelper.BENDA_ID}, BacaHelper.BENDA_ID + "==" + rowId, null,
            null, null, null, null);
    StringBuffer buffer= new StringBuffer();

    if (cursor.moveToFirst()) {
        {
            //byte[] bImageOne=cursor.getBlob(cursor.getColumnIndex(BacaHelper.BENDA_IMAGE));
            byte[] bImageOne = cursor.getBlob(1);
            buffer.append(bImageOne);
        }
    }
    db.close();
    return buffer.toString();
}

Baca.java

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.benda_read);
        bacaHelper= new BacaDatabaseAdapter(this);
        bIOne = (ImageView) findViewById(R.id.imageOne);

        passVar = getIntent().getStringExtra(benda.ID_EXTRA);
        String bendaIOne = bacaHelper.displayImageBendaOne(passVar);
        Log.e("Byte[] ", bendaIOne);

        ByteArrayInputStream imageStream = new ByteArrayInputStream(bendaIOne.getBytes());
        theImage = BitmapFactory.decodeStream(imageStream);
        imageStream.reset();
        bIOne.setImageBitmap(theImage);
    }

目前没有语法错误，但是当我运行我的应用程序时，图像没有出现。在 LogCat 中显示 SKImageDecoder::Factory 返回 null。这句话是什么意思？我无法弄清楚上面的编码。我决定将图像转换为字节数组，再转换为字符串，再转换为字节数组，再转换为图像。这是一个漫长的过程，因为我不知道如何直接从数据库中检索字节数组的值。谁能指出我应该做什么？提前致谢。

已更新。

这是我将图像转换为字节数组并保存在数据库中的 class。

protected void onActivityResult (int requestCode, int resultCode, Intent data) {
        if (resultCode != RESULT_OK)
            return;

        switch (requestCode) {
            case CAMERA_REQUEST:

                Bundle extras = data.getExtras();
                String bendaTambah=benda.getText().toString();

                if (extras != null) {
                    Bitmap yourImage = extras.getParcelable("data");
                    // convert bitmap to byte
                    ByteArrayOutputStream stream = new ByteArrayOutputStream();
                    yourImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
                    byte imageInByte[] = stream.toByteArray();
                    Log.e("output before conversion", imageInByte.toString());
                    // Inserting Contacts
                    Log.d("Insert: ", "Inserting ..");
                    bacaHelper.addContact(new BendaCall(bendaTambah, imageInByte, passVar));
                    Intent i = new Intent(benda.this,
                            benda.class);
                    startActivity(i);
                    finish();

                }
                break;
            case PICK_FROM_GALLERY:
                Bundle extras2 = data.getExtras();
                String bendaTambah2=benda.getText().toString();

                if (extras2 != null) {
                    Bitmap yourImage = extras2.getParcelable("data");
                    // convert bitmap to byte
                    ByteArrayOutputStream stream = new ByteArrayOutputStream();
                    yourImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
                    byte imageInByte[] = stream.toByteArray();
                    Log.e("output before conversion", imageInByte.toString());
                    // Inserting Contacts
                    Log.d("Insert: ", "Inserting ..");
                    bacaHelper.addContact(new BendaCall(bendaTambah2, imageInByte, passVar));
                    Intent i = new Intent(benda.this,
                            benda.class);
                    startActivity(i);
                    finish();
                } else{
                   Message.message(this, "Tidak berjaya menambah gambar ");
                }

                break;
        }
    }

Answer 1

试试这个代码

像这样修改您的 displayImageBendaOne 方法

public Bitmap displayImageBendaOne(String rowId){
SQLiteDatabase db=helper.getReadableDatabase();

Cursor cursor = db.query(true, BacaHelper.TABLE_NAME_BENDA, new String[] {BacaHelper.UID,
                BacaHelper.BENDA, BacaHelper.BENDA_IMAGE, BacaHelper.BENDA_ID}, BacaHelper.BENDA_ID + "==" + rowId, null,
        null, null, null, null);
//StringBuffer buffer= new StringBuffer();
Bitmap bm=null;
if (cursor.moveToFirst()) {
    {
        //byte[] bImageOne=cursor.getBlob(cursor.getColumnIndex(BacaHelper.BENDA_IMAGE));
        byte[] bImageOne = cursor.getBlob(1);

         bm=BitmapFactory.decodeByteArray(bImageOne , 0, bImageOne.length);
       // buffer.append(bImageOne);
    }
}
db.close();
return bm;

}

在你的 onCreate 方法中而不是

  String bendaIOne = bacaHelper.displayImageBendaOne(passVar);
    Log.e("Byte[] ", bendaIOne);

    ByteArrayInputStream imageStream = new ByteArrayInputStream(bendaIOne.getBytes());
    theImage = BitmapFactory.decodeStream(imageStream);
    imageStream.reset();
    bIOne.setImageBitmap(theImage);

使用这个

Bitmap image=bacaHelper.displayImageBendaOne(passVar);
bIOne.setImageBitmap(image);

打开相机的代码

 if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
                  {
                     // String s=sharedPreferences.getString("source", "");
                        Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                        File file = new File(Environment.getExternalStorageDirectory()+File.separator + "image.jpg");
                        path1=Environment.getExternalStorageDirectory()+File.separator + "image.jpg";
                        intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
                        startActivityForResult(intent, CAPTURE_IMAGE_FULLSIZE_ACTIVITY_REQUEST_CODE);
                  }
                  else
                  {
                      ContextWrapper contextWrapper = new ContextWrapper(AddItem.this);
                      File file =new File(contextWrapper.getDir("Inventory", Context.MODE_PRIVATE)+File.separator + "image.jpg");
                      path1=contextWrapper.getDir("Inventory", Context.MODE_PRIVATE)+File.separator + "image.jpg";
                      Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                    //  File file = new File(Environment.getExternalStorageDirectory()+File.separator + "image.jpg");
                        intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
                        startActivityForResult(intent, CAPTURE_IMAGE_FULLSIZE_ACTIVITY_REQUEST_CODE);
                  }

从相机获取图像的代码

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

        if (resultCode == AddItem.this.RESULT_OK) 
        {
            if (requestCode == CAPTURE_IMAGE_FULLSIZE_ACTIVITY_REQUEST_CODE) 
         {//if image is captured from camera
   //    count++;
                 Bitmap bitmap;
                 String fname;
            if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
              {
                 File file = new File(Environment.getExternalStorageDirectory()+File.separator + "image.jpg");
                    BitmapFactory.Options btmapOptions = new BitmapFactory.Options();

                    Bitmap bm = BitmapFactory.decodeFile(file.getAbsolutePath(),btmapOptions);
                      bitmap = decodeSampledBitmapFromFile(file.getAbsolutePath(), 500, 500);
                      fname="image.jpg";

                     try {
                         ExifInterface exif = new ExifInterface(file.getAbsolutePath()); 
                         int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 
                                             ExifInterface.ORIENTATION_NORMAL);
                         int rotate = 0;
                            switch(orientation) {
                               case  ExifInterface.ORIENTATION_ROTATE_270:
                                    rotate-=90;break;
                               case  ExifInterface.ORIENTATION_ROTATE_180:
                                    rotate-=90;break;
                               case  ExifInterface.ORIENTATION_ROTATE_90:
                                    rotate-=90;break;
                               }
                                // Log.d("Fragment", "EXIF info for file " + name1 + ": " + rotate);
                            } catch (IOException e) {
                             //   Log.d("Fragment", "Could not get EXIF info for file " + name1 + ": " + e);
                            }
                 //    viewImage.setImageBitmap(bitmap);
              }
            else
            {
                  ContextWrapper contextWrapper = new ContextWrapper(AddItem.this);
                  File file =new File(contextWrapper.getDir("Inventory", Context.MODE_PRIVATE)+File.separator + "image.jpg");
                // File file = new File(Environment.getExternalStorageDirectory()+File.separator + "image.jpg");
                    BitmapFactory.Options btmapOptions = new BitmapFactory.Options();

                    Bitmap bm = BitmapFactory.decodeFile(file.getAbsolutePath(),btmapOptions);
                      bitmap = decodeSampledBitmapFromFile(file.getAbsolutePath(), 500, 500);
                      fname="image.jpg";
                   //  viewImage.setImageBitmap(bitmap);
            }

            //add to database


            addlabel.setVisibility(View.VISIBLE);
            Inventory inv= new Inventory(bitmap,fname,name,date);
            DbHelper.open();
            long count=DbHelper.insertInvDetails(inv);
            //Toast.makeText(AddItem.this, count+"", Toast.LENGTH_LONG).show();
            DbHelper.close();

    }

        }

    }

获取全尺寸图像的代码

 public static Bitmap decodeSampledBitmapFromFile(String path, int reqWidth, int reqHeight) 
    { // BEST QUALITY MATCH

        //First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        // Calculate inSampleSize, Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        options.inPreferredConfig = Bitmap.Config.RGB_565;
        int inSampleSize = 1;

        if (height > reqHeight) 
        {
            inSampleSize = Math.round((float)height / (float)reqHeight);
        }
        int expectedWidth = width / inSampleSize;

        if (expectedWidth > reqWidth) 
        {
            //if(Math.round((float)width / (float)reqWidth) > inSampleSize) // If bigger SampSize..
            inSampleSize = Math.round((float)width / (float)reqWidth);
        }

        options.inSampleSize = inSampleSize;

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;

        return BitmapFactory.decodeFile(path, options);
    }

实用程序class 用于将图像转换为字节数组并将其解码回 bimap

import java.io.ByteArrayOutputStream;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.util.Log;

public class Utility {
// convert from bitmap to byte array
public static byte[] getBytes(Bitmap bitmap) {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    bitmap.compress(CompressFormat.PNG, 0, stream);

    return stream.toByteArray();
}

// convert from byte array to bitmap
public static Bitmap getPhoto(byte[] image) {
    Log.i("", image.toString());
    return BitmapFactory.decodeByteArray(image, 0, image.length);
}

}

插入数据的数据库代码

public long insertInvDetails(Inventory invent) {
    mDb = mDbHelper.getWritableDatabase();


    ContentValues cv = new ContentValues();
    cv.put(EMP_PHOTO, Utility.getBytes(invent.getBitmap()));
    cv.put(EMP_NAME, invent.getName());
    cv.put(EMP_PNAME, invent.getPersonName());
    cv.put(EMP_Date, invent.getDate());
    cv.put("IsDeleted", 0);
    long count=mDb.insert(INVENTORY_TABLE, null, cv);
    return count;
}

更新

检索数据的代码

public List<Inventory> getSelectedContacts() {
    List<Inventory> invlist = new ArrayList<Inventory>();
    // Select All Query
    mDb = mDbHelper.getWritableDatabase();
    Cursor cursor = mDb.query(true, INVENTORY_TABLE, new String[] {EMP_ID, EMP_PHOTO,
            EMP_NAME, EMP_PNAME,EMP_Date }, "IsDeleted=1", null, null, null, null, null);
    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Inventory inv = new Inventory();
            inv.setID(cursor.getInt(0));
            byte[] blob = cursor.getBlob(cursor.getColumnIndex(EMP_PHOTO));
            inv.setBitmap(Utility.getPhoto(blob));
            inv.setName(cursor.getString(2));
            inv.setPersonName(cursor.getString(3));
            inv.setDate(cursor.getString(4));
            // Adding contact to list
            invlist.add(inv);
        } while (cursor.moveToNext());
    }

    mDb.close();
    // return contact list
    return invlist;

}

调用 getSelectedContacts 并在线性布局中显示图像的代码

    List<Inventory> select_contacts = db.getSelectedContacts();
    LinearLayout newll=new LinearLayout(MainPage.this);
    newll.setOrientation(LinearLayout.VERTICAL);
    for (Inventory cn : select_contacts) {

     ImageView myImage = new ImageView(MainPage.this);
      myImage.setImageBitmap(cn.getBitmap());
     newll.addView(myImage);

    }
    //add newll to your parent view

这是我的存货 class 持有价值

package com.graficali.inventorysystem;

import android.graphics.Bitmap;

public class Inventory {
private Bitmap bmp;
private String filename;
private String personname;
 String created_at;
private int id;

public Inventory()
{

}
public Inventory(Bitmap b, String n, String pn, String created_at) {
    bmp = b;
    filename = n;
    personname = pn;
    this.created_at=created_at;
}

public Bitmap getBitmap() {
    return bmp;
}

public String getName() {
    return filename;
}
public String getDate() {
    return this.created_at;
}

public int getID() {
    return this.id;
}
public String getPersonName() {
    return personname;
}
public void setBitmap(Bitmap bmp) {
    this.bmp=bmp;
}

public void setName(String filename) {
     this.filename=filename;
}

public void setID(int id) {
     this.id=id;
}

public void setPersonName(String personname)
{

    this.personname=personname;
}
public void setDate(String created_at) {
    this.created_at = created_at;
}

}

无法从 SQLite 检索图像。 SKImageDecoder::Factory 返回空值

Unable to retrieve image from SQLite. SKImageDecoder::Factory returned null

sqlite

android

image

display