1

我试图从数据库加载图像，但图像没有加载，logcat 显示 null 是不是 simethinf 与我编程的方式..

imgdisplay = (ImageView) findViewById(R.id.imgIcon);
myDB = this.openOrCreateDatabase("hello", MODE_PRIVATE, null);

Cursor c = myDB.rawQuery(
    "SELECT image  FROM employee_details WHERE name= 'vv'", null);

if (c.getCount() > 0) {
    c.moveToFirst();
    do {
        byte[] blob = c.getBlob(c.getColumnIndex("image"));
        ImageView iv = (ImageView) findViewById(R.id.imgIcon);
        iv.setImageBitmap(BitmapFactory.decodeByteArray(blob, 0,blob.length));
    } while (c.moveToNext());
}
c.close();
myDB.close();

Logcat 错误是...

08-02 04:51:25.471: D/skia(8433): --- SkImageDecoder::Factory returned null
4

3 回答 3

2

试试下面的代码..

byte[] Image_bytes = cursor.getBlob(cursor.getColumnIndex("image"));
ImageView iv = (ImageView) findViewById(R.id.imgIcon);
iv.setImageBitmap(new ImageConversation().convertArrayToBmp(Image_bytes));

...

public Bitmap convertArrayToBmp(byte[] array) {
    Bitmap bitmap = BitmapFactory.decodeByteArray(array, 0, array.length);
    return bitmap ;
}

使用以下循环

c.moveToFirst();
while(!c.isAfterLast()) {
    byte[] blob = c.getBlob(c.getColumnIndex("image"));
    ImageView iv = (ImageView) findViewById(R.id.imgIcon);
    iv.setImageBitmap(BitmapFactory.decodeByteArray(blob, 0,blob.length));
    c.moveToNext()
}
于 2013-08-02T05:10:01.730 回答
0

尝试做这样的事情 -

如果您将图像作为字符串存储在数据库中

 if(image.isEmpty())
  {
   System.out.println("is empty image");

  }
  else
  {
   byte[] decodedByte = Base64.decode(image, 0);
   Bitmap bm = BitmapFactory.decodeByteArray(decodedByte, 0,
     decodedByte.length);
   iv.setImageBitmap(bm);
  }
于 2013-08-02T05:44:23.760 回答
0

我没有找到将图像保存到数据库的方法，所以我开始将图像直接保存到内部存储器，这不是问题的答案，但可能会给同样不知道的其他人一些想法去做...

要保存到内部存储器...

   File fileWithinMyDir = getApplicationContext().getFilesDir();  
    try 
          {
              StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
              .permitAll().build();
          StrictMode.setThreadPolicy(policy); 
           URL url = new URL("http://t2.gstatic.com  /images?q=tbn:ANd9GcQjZgUffqqe2mKKb5VOrDNd-ZxD7sJOU7WAHlFAy6PLbtXpyQZYdw");
           File file = new File( fileWithinMyDir.getAbsolutePath()  + "/" +"sun.jpg");
           URLConnection ucon = url.openConnection();
           InputStream is = ucon.getInputStream();
           BufferedInputStream bis = new BufferedInputStream(is);
           ByteArrayBuffer baf = new ByteArrayBuffer(50);
           int current = 0;
           while ((current = bis.read()) != -1) 
           {
            baf.append((byte) current);
           }

           FileOutputStream fos = new FileOutputStream(file);
           fos.write(baf.toByteArray());
           fos.close();
        } 
        catch (IOException e) 
        {
            Log.e("download", e.getMessage());
        }

从内部存储器加载图像..

 StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
          .permitAll().build();
           StrictMode.setThreadPolicy(policy); 
          mImgView1 = (ImageView) findViewById(R.id.mImgView1); 

          Bitmap bitmap = BitmapFactory.decodeFile(fileWithinMyDir.getAbsolutePath()  + "/" +"sunn"+".file extension");
          mImgView1.setImageBitmap(bitmap);

这适用于由于“android.os.networkonmainthreadexception”而显示错误的较新的android

如果你想解决问题，你也可以使用 AsyncTask ......

于 2013-08-13T06:04:35.863 回答