无法从android中的sqlite数据库加载图像
我试图从数据库加载图像,但图像未加载,logcat显示null 这和我编程的方式一样吗无法从android中的sqlite数据库加载图像,android,database,sqlite,blob,Android,Database,Sqlite,Blob,我试图从数据库加载图像,但图像未加载,logcat显示null 这和我编程的方式一样吗 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'", nul
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
请尝试下面的代码
byte[] Image_bytes = cursor.getBlob(cursor.getColumnIndex("image"));
ImageView iv = (ImageView) findViewById(R.id.imgIcon);
iv.setImageBitmap(new ImageConversation().convertArrayToBmp(Image_bytes));
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()
}
试着做这样的事情- 若要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);
}
我没有找到将图像保存到数据库的方法,因此我开始将图像直接保存到内存中,这不是问题的答案,但可能会给其他也没有任何想法的人一些想法 要保存到内存中
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());
}
要从内存加载图像
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);
这适用于因“android.os.networkonmainthreadexception”而显示错误的较新android
如果你想解决这个问题,你也可以使用AsyncTask…你检查过你的表返回字节数组了吗???@ArmansTranger你能给我做这件事的代码吗???检查一下你的数据库伙伴。名称“vv”的“图像”列中是否有任何图像数据。@Armanstranger是。。它表明[B@40d12280only它显示了这么多字符串???它显示了ImageConversation()上的错误,显示要进行新类检查的do while循环..可能永远不会结束。
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);