如何保存和从Android的SQL数据库精简版图像retrive [英] how to save and retrive images from sql lite database in android
本文介绍了如何保存和从Android的SQL数据库精简版图像retrive的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我按照这个教程的http://vimaltuts.com/android-tutorial-for-beginners/android-sqlite-database-example只是告诉我,我如何在这个code增加一个字段来拍摄图像作为输入和显示?
请帮我
进口android.app.Activity;
进口android.app.AlertDialog;
进口android.os.AsyncTask;
进口android.os.Bundle;
进口android.view.View;
进口android.view.View.OnClickListener;
进口android.widget.Button;
进口android.widget.EditText; 公共类AddEditCountry延伸活动{ 私人长期ROWID;
私人的EditText nameEt;
私人的EditText卡佩;
私人的EditText codeET; @覆盖
公共无效的onCreate(捆绑savedInstanceState)
{
super.onCreate(savedInstanceState);
的setContentView(R.layout.add_country); nameEt =(EditText上)findViewById(R.id.nameEdit);
卡佩=(EditText上)findViewById(R.id.capEdit);
codeET =(EditText上)findViewById(R.id. codeEdit的); 捆绑额外= getIntent()getExtras()。 如果(临时演员!= NULL)
{
ROWID = extras.getLong(ROW_ID);
nameEt.setText(extras.getString(名字));
capEt.setText(extras.getString(上限));
codeEt.setText(extras.getString(code));
} 按钮saveButton =(按钮)findViewById(R.id.saveBtn);
saveButton.setOnClickListener(新OnClickListener(){ 公共无效的onClick(视图v)
{
如果(nameEt.getText()。长度()!= 0)
{
AsyncTask的saveContactTask =
新的AsyncTask()
{
@覆盖
保护对象doInBackground(对象... PARAMS)
{
saveContact();
返回null;
} @覆盖
保护无效onPostExecute(对象结果)
{
完();
}
}; saveContactTask.execute((Object []对象),NULL);
} 其他
{
AlertDialog.Builder警报=新
AlertDialog.Builder(AddEditCountry.this);
alert.setTitle(R.string.errorTitle);
alert.setMessage(R.string.errorMessage);
alert.setPositiveButton(R.string.errorButton,NULL);
alert.show();
}
}
});
} 私人无效saveContact()
{
DatabaseConnector dbConnector =新DatabaseConnector(本); 如果(getIntent()。getExtras()== NULL)
{
dbConnector.insertContact(nameEt.getText()。的toString()
capEt.getText()。的toString()
。codeEt.getText()的toString());
}
其他
{
dbConnector.updateContact(ROWID,
nameEt.getText()。的toString()
capEt.getText()。的toString()
。codeEt.getText()的toString());
}
}
}
进口android.os.AsyncTask;
进口android.os.Bundle;
进口android.app.ListActivity;
进口android.content.Intent;
进口android.database.Cursor;
进口android.view.Menu;
进口android.view.MenuInflater;
进口android.view.MenuItem;
进口android.view.View;
进口android.widget.AdapterView;
进口android.widget.CursorAdapter;
进口android.widget.ListView;
进口android.widget.SimpleCursorAdapter;
进口android.widget.AdapterView.OnItemClickListener; 公共类CountryList扩展ListActivity { 公共静态最后弦乐ROW_ID =ROW_ID;
私人的ListView conListView;
私人的CursorAdapter conAdapter; @覆盖
公共无效的onCreate(捆绑savedInstanceState){
super.onCreate(savedInstanceState);
conListView = getListView();
conListView.setOnItemClickListener(viewConListener); //每名映射到一个TextView
的String [] =由新的String [] {名};
INT []为= INT新[] {} R.id.countryTextView;
conAdapter =新SimpleCursorAdapter(CountryList.this,R.layout.country_list,
空,从,到);
setListAdapter(conAdapter); //设置适配器
}
@覆盖
保护无效onResume()
{
super.onResume();
新GetContacts()执行((Object []对象),NULL);
}
@覆盖
保护无效的onStop()
{
光标光标= conAdapter.getCursor(); 如果(指针!= NULL)
cursor.deactivate(); conAdapter.changeCursor(NULL);
super.onStop();
}
私有类GetContacts扩展的AsyncTask
{
DatabaseConnector dbConnector =新DatabaseConnector(CountryList.this); @覆盖
保护光标doInBackground(对象... PARAMS)
{
dbConnector.open();
返回dbConnector.getAllContacts();
} @覆盖
保护无效onPostExecute(光标结果)
{
conAdapter.changeCursor(结果); //设置适配器的光标
dbConnector.close();
}
} @覆盖
公共布尔onCreateOptionsMenu(菜单菜单)
{
super.onCreateOptionsMenu(菜单);
MenuInflater吹气= getMenuInflater();
inflater.inflate(R.menu.country_menu,菜单);
返回true;
} @覆盖
公共布尔onOptionsItemSelected(菜单项项)
{
意向书的addContact =新意图(CountryList.this,AddEditCountry.class);
startActivity(的addContact);
返回super.onOptionsItemSelected(项目);
}OnItemClickListener viewConListener =新OnItemClickListener()
{
公共无效onItemClick(适配器视图为arg0,ARG1观,诠释ARG2,长ARG3)
{
意图viewCon =新意图(CountryList.this,ViewCountry.class);
viewCon.putExtra(ROW_ID,ARG3);
startActivity(viewCon);
}
}; } 进口android.app.Activity;
进口android.app.AlertDialog;
进口android.content.DialogInterface;
进口android.content.Intent;
进口android.database.Cursor;
进口android.os.AsyncTask;
进口android.os.Bundle;
进口android.view.Menu;
进口android.view.MenuInflater;
进口android.view.MenuItem;
进口android.widget.TextView; 公共类ViewCountry延伸活动{ 私人长期ROWID;
私人TextView的nameTv;
私人TextView的capTv;
私人TextView的codeTV; @覆盖
公共无效的onCreate(捆绑savedInstanceState)
{
super.onCreate(savedInstanceState);
的setContentView(R.layout.view_country); setUpViews();
捆绑额外= getIntent()getExtras()。
ROWID = extras.getLong(CountryList.ROW_ID);
} 私人无效setUpViews(){
nameTv =(的TextView)findViewById(R.id.nameText);
capTv =(的TextView)findViewById(R.id.capText);
codeTV =(的TextView)findViewById(R.id. codeTEXT);
} @覆盖
保护无效onResume()
{
super.onResume();
新LoadContacts()执行(ROWID)。
} 私有类LoadContacts扩展的AsyncTask
{
DatabaseConnector dbConnector =新DatabaseConnector(ViewCountry.this); @覆盖
保护光标doInBackground(长... PARAMS)
{
dbConnector.open();
返回dbConnector.getOneContact(PARAMS [0]);
} @覆盖
保护无效onPostExecute(光标结果)
{
super.onPostExecute(结果); result.moveToFirst();
//取得每个数据项的列索引
INT nameIndex = result.getColumnIndex(名称);
INT capIndex = result.getColumnIndex(上限);
INT codeINDEX = result.getColumnIndex(code); nameTv.setText(result.getString(nameIndex));
capTv.setText(result.getString(capIndex));
codeTv.setText(result.getString(codeINDEX)); result.close();
dbConnector.close();
}
}
@覆盖
公共布尔onCreateOptionsMenu(菜单菜单)
{
super.onCreateOptionsMenu(菜单);
MenuInflater吹气= getMenuInflater();
inflater.inflate(R.menu.view_country_menu,菜单);
返回true;
} @覆盖
公共布尔onOptionsItemSelected(菜单项项)
{
开关(item.getItemId())
{
案例R.id.editItem:
意向addEditContact =
新的意图(这一点,AddEditCountry.class); addEditContact.putExtra(CountryList.ROW_ID,ROWID);
addEditContact.putExtra(名,nameTv.getText());
addEditContact.putExtra(上限,capTv.getText());
addEditContact.putExtra(code,codeTv.getText());
startActivity(addEditContact);
返回true; 案例R.id.deleteItem:
deleteContact();
返回true; 默认:
返回super.onOptionsItemSelected(项目);
}
} 私人无效deleteContact()
{ AlertDialog.Builder警报=新AlertDialog.Builder(ViewCountry.this); alert.setTitle(R.string.confirmTitle);
alert.setMessage(R.string.confirmMessage); alert.setPositiveButton(R.string.delete_btn,
新DialogInterface.OnClickListener()
{
公共无效的onClick(DialogInterface对话框,INT按钮)
{
最后DatabaseConnector dbConnector =
新DatabaseConnector(ViewCountry.this); AsyncTask的DeleteTask活动=
新的AsyncTask()
{
@覆盖
保护对象doInBackground(长... PARAMS)
{
dbConnector.deleteContact(PARAMS [0]);
返回null;
} @覆盖
保护无效onPostExecute(对象结果)
{
完();
}
}; deleteTask.execute(新长征[] {ROWID});
}
}
); alert.setNegativeButton(R.string.cancel_btn,NULL).show();
}
}
进口android.content.ContentValues;
进口android.content.Context;
进口android.database.Cursor;
进口android.database.SQLException;
进口android.database.sqlite.SQLiteDatabase;
公共类DatabaseConnector {私有静态最后弦乐DB_NAME =WorldCountries;
私人SQLiteDatabase数据库;
私人DatabaseOpenHelper dbOpenHelper;公共DatabaseConnector(上下文的背景下){
dbOpenHelper =新DatabaseOpenHelper(上下文,DB_NAME,空,1);
} 公共无效的open()抛出的SQLException
{
//打开数据库中读取/写入模式
数据库= dbOpenHelper.getWritableDatabase();
} 公共无效的close()
{
如果(数据库!= NULL)
database.close();
} 公共无效insertContact(字符串名称,字符串帽,字符串code)
{
ContentValues NEWCON =新ContentValues();
newCon.put(名,名);
newCon.put(帽,帽子);
newCon.put(code,code); 打开();
database.insert(国家,空,NEWCON);
关();
}
公共无效updateContact(长ID,字符串名称,字符串
帽,字符串code)
{
ContentValues editCon =新ContentValues();
editCon.put(名,名);
editCon.put(帽,帽子);
editCon.put(code,code); 打开();
database.update(国家,editCon,_id =+ ID,NULL);
关();
}
公共光标getAllContacts()
{
返回database.query(国家,新的String [] {_id
名称},
NULL,NULL,NULL,NULL,名);
} 公共光标getOneContact(长ID)
{
返回database.query(国家,NULL,_id =+ ID,空,
NULL,NULL,NULL);
} 公共无效deleteContact(长ID)
{
打开();
database.delete(国家,_id =+ ID,NULL);
关();
}
} 进口android.content.Context;
进口android.database.sqlite.SQLiteDatabase;
进口android.database.sqlite.SQLiteDatabase.CursorFactory;
进口android.database.sqlite.SQLiteOpenHelper; 公共类DatabaseOpenHelper扩展SQLiteOpenHelper {公共DatabaseOpenHelper(上下文的背景下,字符串名称,
CursorFactory工厂,诠释的版本){
超(背景下,名称,厂家,版本);
}@覆盖
公共无效的onCreate(SQLiteDatabase DB){
字符串的createQuery =CREATE TABLE国家(_id整数主键
自动增量,名称,帽,code);;
db.execSQL(的createQuery);
}@覆盖
公共无效onUpgrade(SQLiteDatabase分贝,INT oldVersion,诠释静态网页){}}
解决方案
您可以轻松地添加字段 BLOB
的输入SQL,并把图像像字节集:
//当写入到数据库:
ByteArrayOutputStream outStr =新ByteArrayOutputStream();
image.com preSS(比较pressFormat.PNG,100,outStr);
字节[] = BLOB outStr.toByteArray();contentValues.put(形象,BLOB);
//而来自光标阅读:
字节[] = BLOB cursor.getBlob(图像);
位图图像= BitmapFactory.de codeByteArray的(BLOB,0,blob.length);
i follow this tutorial http://vimaltuts.com/android-tutorial-for-beginners/android-sqlite-database-example just tell me how do i add one more field in this code to take images as input and display?
please help me
import android.app.Activity;
import android.app.AlertDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class AddEditCountry extends Activity {
private long rowID;
private EditText nameEt;
private EditText capEt;
private EditText codeEt;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.add_country);
nameEt = (EditText) findViewById(R.id.nameEdit);
capEt = (EditText) findViewById(R.id.capEdit);
codeEt = (EditText) findViewById(R.id.codeEdit);
Bundle extras = getIntent().getExtras();
if (extras != null)
{
rowID = extras.getLong("row_id");
nameEt.setText(extras.getString("name"));
capEt.setText(extras.getString("cap"));
codeEt.setText(extras.getString("code"));
}
Button saveButton =(Button) findViewById(R.id.saveBtn);
saveButton.setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
if (nameEt.getText().length() != 0)
{
AsyncTask saveContactTask =
new AsyncTask()
{
@Override
protected Object doInBackground(Object... params)
{
saveContact();
return null;
}
@Override
protected void onPostExecute(Object result)
{
finish();
}
};
saveContactTask.execute((Object[]) null);
}
else
{
AlertDialog.Builder alert = new
AlertDialog.Builder(AddEditCountry.this);
alert.setTitle(R.string.errorTitle);
alert.setMessage(R.string.errorMessage);
alert.setPositiveButton(R.string.errorButton, null);
alert.show();
}
}
});
}
private void saveContact()
{
DatabaseConnector dbConnector = new DatabaseConnector(this);
if (getIntent().getExtras() == null)
{
dbConnector.insertContact(nameEt.getText().toString(),
capEt.getText().toString(),
codeEt.getText().toString());
}
else
{
dbConnector.updateContact(rowID,
nameEt.getText().toString(),
capEt.getText().toString(),
codeEt.getText().toString());
}
}
}
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.CursorAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.AdapterView.OnItemClickListener;
public class CountryList extends ListActivity {
public static final String ROW_ID = "row_id";
private ListView conListView;
private CursorAdapter conAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
conListView=getListView();
conListView.setOnItemClickListener(viewConListener);
// map each name to a TextView
String[] from = new String[] { "name" };
int[] to = new int[] { R.id.countryTextView };
conAdapter = new SimpleCursorAdapter(CountryList.this, R.layout.country_list,
null, from, to);
setListAdapter(conAdapter); // set adapter
}
@Override
protected void onResume()
{
super.onResume();
new GetContacts().execute((Object[]) null);
}
@Override
protected void onStop()
{
Cursor cursor = conAdapter.getCursor();
if (cursor != null)
cursor.deactivate();
conAdapter.changeCursor(null);
super.onStop();
}
private class GetContacts extends AsyncTask
{
DatabaseConnector dbConnector = new DatabaseConnector(CountryList.this);
@Override
protected Cursor doInBackground(Object... params)
{
dbConnector.open();
return dbConnector.getAllContacts();
}
@Override
protected void onPostExecute(Cursor result)
{
conAdapter.changeCursor(result); // set the adapter's Cursor
dbConnector.close();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.country_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{
Intent addContact = new Intent(CountryList.this, AddEditCountry.class);
startActivity(addContact);
return super.onOptionsItemSelected(item);
}
OnItemClickListener viewConListener = new OnItemClickListener()
{
public void onItemClick(AdapterView arg0, View arg1, int arg2,long arg3)
{
Intent viewCon = new Intent(CountryList.this, ViewCountry.class);
viewCon.putExtra(ROW_ID, arg3);
startActivity(viewCon);
}
};
}
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.TextView;
public class ViewCountry extends Activity {
private long rowID;
private TextView nameTv;
private TextView capTv;
private TextView codeTv;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.view_country);
setUpViews();
Bundle extras = getIntent().getExtras();
rowID = extras.getLong(CountryList.ROW_ID);
}
private void setUpViews() {
nameTv = (TextView) findViewById(R.id.nameText);
capTv = (TextView) findViewById(R.id.capText);
codeTv = (TextView) findViewById(R.id.codeText);
}
@Override
protected void onResume()
{
super.onResume();
new LoadContacts().execute(rowID);
}
private class LoadContacts extends AsyncTask
{
DatabaseConnector dbConnector = new DatabaseConnector(ViewCountry.this);
@Override
protected Cursor doInBackground(Long... params)
{
dbConnector.open();
return dbConnector.getOneContact(params[0]);
}
@Override
protected void onPostExecute(Cursor result)
{
super.onPostExecute(result);
result.moveToFirst();
// get the column index for each data item
int nameIndex = result.getColumnIndex("name");
int capIndex = result.getColumnIndex("cap");
int codeIndex = result.getColumnIndex("code");
nameTv.setText(result.getString(nameIndex));
capTv.setText(result.getString(capIndex));
codeTv.setText(result.getString(codeIndex));
result.close();
dbConnector.close();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.view_country_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.editItem:
Intent addEditContact =
new Intent(this, AddEditCountry.class);
addEditContact.putExtra(CountryList.ROW_ID, rowID);
addEditContact.putExtra("name", nameTv.getText());
addEditContact.putExtra("cap", capTv.getText());
addEditContact.putExtra("code", codeTv.getText());
startActivity(addEditContact);
return true;
case R.id.deleteItem:
deleteContact();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void deleteContact()
{
AlertDialog.Builder alert = new AlertDialog.Builder(ViewCountry.this);
alert.setTitle(R.string.confirmTitle);
alert.setMessage(R.string.confirmMessage);
alert.setPositiveButton(R.string.delete_btn,
new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int button)
{
final DatabaseConnector dbConnector =
new DatabaseConnector(ViewCountry.this);
AsyncTask deleteTask =
new AsyncTask()
{
@Override
protected Object doInBackground(Long... params)
{
dbConnector.deleteContact(params[0]);
return null;
}
@Override
protected void onPostExecute(Object result)
{
finish();
}
};
deleteTask.execute(new Long[] { rowID });
}
}
);
alert.setNegativeButton(R.string.cancel_btn, null).show();
}
}
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
public class DatabaseConnector {
private static final String DB_NAME = "WorldCountries";
private SQLiteDatabase database;
private DatabaseOpenHelper dbOpenHelper;
public DatabaseConnector(Context context) {
dbOpenHelper = new DatabaseOpenHelper(context, DB_NAME, null, 1);
}
public void open() throws SQLException
{
//open database in reading/writing mode
database = dbOpenHelper.getWritableDatabase();
}
public void close()
{
if (database != null)
database.close();
}
public void insertContact(String name, String cap, String code)
{
ContentValues newCon = new ContentValues();
newCon.put("name", name);
newCon.put("cap", cap);
newCon.put("code", code);
open();
database.insert("country", null, newCon);
close();
}
public void updateContact(long id, String name, String
cap,String code)
{
ContentValues editCon = new ContentValues();
editCon.put("name", name);
editCon.put("cap", cap);
editCon.put("code", code);
open();
database.update("country", editCon, "_id=" + id, null);
close();
}
public Cursor getAllContacts()
{
return database.query("country", new String[] {"_id",
"name"},
null, null, null, null, "name");
}
public Cursor getOneContact(long id)
{
return database.query("country", null, "_id=" + id, null,
null, null, null);
}
public void deleteContact(long id)
{
open();
database.delete("country", "_id=" + id, null);
close();
}
}
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseOpenHelper extends SQLiteOpenHelper {
public DatabaseOpenHelper(Context context, String name,
CursorFactory factory, int version) {
super(context, name, factory, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
String createQuery = "CREATE TABLE country (_id integer primary key
autoincrement,name, cap, code);";
db.execSQL(createQuery);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
解决方案
You can easily add field of BLOB
type in sql, and put images like set of bytes:
//while writing to db:
ByteArrayOutputStream outStr = new ByteArrayOutputStream();
image.compress(CompressFormat.PNG, 100, outStr);
byte[] blob = outStr.toByteArray();
contentValues.put("image", blob);
//while reading from cursor:
byte[] blob = cursor.getBlob("image");
Bitmap image = BitmapFactory.decodeByteArray(blob, 0, blob.length);
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