我如何从 sql lite 中检索图像？当我使用重 jpg 图像不显示时，此代码适用于小尺寸图像我该怎么办？我找到了解决方案解码图像，但我把代码放在哪里？下面是我的完整源代码
public class SQLiteDemoActivity extends Activity {
ArrayList<Contact> imageArry = new ArrayList<Contact>();
ContactImageAdapter adapter;
Button BrowseButton;
Button BrowseButton2;
DataBaseHandler db;
ByteArrayOutputStream stream = new ByteArrayOutputStream();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
db = new DataBaseHandler(this);
//get image from drawable
BrowseButton=(Button)findViewById(R.id.BrowseButton);
BrowseButton2=(Button)findViewById(R.id.BrowseButton2);
adapter = new ContactImageAdapter(this, R.layout.screen_list, imageArry);
BrowseButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Bitmap image = BitmapFactory.decodeResource(getResources(),R.drawable.my);
image.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] imageInByte = stream.toByteArray();
Log.d("Insert: ", "Inserting ..");
db.addContact(new Contact("FaceBook", imageInByte));
//display main List view bcard and contact name
//Reading all contacts from database
//
}
});
BrowseButton2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
List<Contact> contacts = db.getAllContacts();
for (Contact cn : contacts) {
String log = "ID:" + cn.getID() + " Name: " + cn.getName() + " ,Image: " +
cn.getImage();
//Writing Contacts to log
Log.d("Result: ", log);
//add contacts data in arrayList
imageArry.add(cn);
}
ListView dataList = (ListView) findViewById(R.id.list);
dataList.setAdapter(adapter);
try {
stream.close();
stream = null;
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
public class Contact {
// private variables
int _id;
String _name;
byte[] _image;
// Empty constructor
public Contact() {
}
// constructor
public Contact(int keyId, String name, byte[] image) {
this._id = keyId;
this._name = name;
this._image = image;
}
// constructor
public Contact(String contactID, String name, byte[] image) {
this._name = name;
this._image = image;
}
// constructor
public Contact(String name, byte[] image) {
this._name = name;
this._image = image;
}
// getting ID
public int getID() {
return this._id;
}
// setting id
public void setID(int keyId) {
this._id = keyId;
}
// getting name
public String getName() {
return this._name;
}
// setting name
public void setName(String name) {
this._name = name;
}
// getting phone number
public byte[] getImage() {
return this._image;
}
// setting phone number
public void setImage(byte[] image) {
this._image = image;
}
}
public class ContactImageAdapter extends ArrayAdapter<Contact>{
Context context;
int layoutResourceId;
//BcardImage data[] = null;
ArrayList<Contact> data=new ArrayList<Contact>();
public ContactImageAdapter(Context context, int layoutResourceId,
ArrayList<Contact>
data) {
super(context, layoutResourceId, data);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.data = data;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
ImageHolder holder = null;
if(row == null)
{
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new ImageHolder();
holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);
holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
row.setTag(holder);
}
else
{
holder = (ImageHolder)row.getTag();
}
Contact picture = data.get(position);
holder.txtTitle.setText("facebook");
//convert byte to bitmap take from contact class
byte[] outImage=picture._image;
ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
Bitmap theImage = BitmapFactory.decodeStream(imageStream);
holder.imgIcon.setImageBitmap(theImage);
return row;
}
static class ImageHolder
{
ImageView imgIcon;
TextView txtTitle;
}
}
import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DataBaseHandler extends SQLiteOpenHelper {
//All Static variables
//Database Version
private static final int DATABASE_VERSION = 1;
//Database Name
private static final String DATABASE_NAME = "imagedb";
//Contacts table name
private static final String TABLE_CONTACTS = "contacts";
//Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_IMAGE = "image";
public DataBaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
//Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_IMAGE + " BLOB" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
//Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
//Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
//Create tables again
onCreate(db);
}
/**
* All CRUD(Create, Read, Update, Delete) Operations
*/
public// Adding new contact
void addContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, contact._name); // Contact Name
values.put(KEY_IMAGE, contact._image); // Contact Phone
//Inserting Row
db.insert(TABLE_CONTACTS, null, values);
db.close(); // Closing database connection
}
//Getting single contact
Contact getContact(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID,
KEY_NAME, KEY_IMAGE }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Contact contact = new Contact(Integer.parseInt(cursor.getString(0)),
cursor.getString(1), cursor.getBlob(1));
//return contact
return contact;
}
//Getting All Contacts
public List<Contact> getAllContacts() {
List<Contact> contactList = new ArrayList<Contact>();
//Select All Query
String selectQuery = "SELECT * FROM contacts ORDER BY name";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
//looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Contact contact = new Contact();
contact.setID(Integer.parseInt(cursor.getString(0)));
contact.setName(cursor.getString(1));
contact.setImage(cursor.getBlob(2));
//Adding contact to list
contactList.add(contact);
} while (cursor.moveToNext());
}
//close inserting data from database
db.close();
//return contact list
return contactList;
}
//Updating single contact
public int updateContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, contact.getName());
values.put(KEY_IMAGE, contact.getImage());
//updating row
return db.update(TABLE_CONTACTS, values, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
}
//Deleting single contact
public void deleteContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_CONTACTS, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
db.close();
}
//Getting contacts Count
public int getContactsCount() {
String countQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();
//return count
return cursor.getCount();
}
<------ from where i used this function------------->
private Bitmap decodeFile(File f) {
try {
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 <
REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale++;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null,
o2);
}
catch (FileNotFoundException e) {
}
return null;
}