Java 如何在android中从数据库向自定义列表视图显示图像?
我已经向SQLite数据库添加了一些数据+图像,但现在我想将它们显示到自定义列表视图中。就像下面的图片(图片链接) 我无法从数据库中检索图像并将其显示到自定义列表视图。我已将图像以BLOB类型存储到数据库中 MainActivity.javaJava 如何在android中从数据库向自定义列表视图显示图像?,java,android,sqlite,Java,Android,Sqlite,我已经向SQLite数据库添加了一些数据+图像,但现在我想将它们显示到自定义列表视图中。就像下面的图片(图片链接) 我无法从数据库中检索图像并将其显示到自定义列表视图。我已将图像以BLOB类型存储到数据库中 MainActivity.java package com.example.crudexamplerepeat; import java.util.List; import android.support.v7.app.ActionBarActivity; import android
package com.example.crudexamplerepeat;
import java.util.List;
import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
Button btn_add_new;
Button btn_old_data;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_add_new = (Button) findViewById(R.id.btn_add_new);
btn_add_new.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(getApplicationContext(),
Add_new_activity.class);
startActivity(i);
}
});
btn_old_data = (Button) findViewById(R.id.btn_old_data);
btn_old_data.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i_new = new Intent(getApplicationContext(),
Old_data_activity.class);
startActivity(i_new);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
package com.example.crudexamplerepeat;
import java.util.ArrayList;
import java.util.List;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class Old_data_activity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_old_data_activity);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.old_data_activity, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
旧_data_activity.java
package com.example.crudexamplerepeat;
import java.util.List;
import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
Button btn_add_new;
Button btn_old_data;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_add_new = (Button) findViewById(R.id.btn_add_new);
btn_add_new.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(getApplicationContext(),
Add_new_activity.class);
startActivity(i);
}
});
btn_old_data = (Button) findViewById(R.id.btn_old_data);
btn_old_data.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i_new = new Intent(getApplicationContext(),
Old_data_activity.class);
startActivity(i_new);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
package com.example.crudexamplerepeat;
import java.util.ArrayList;
import java.util.List;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class Old_data_activity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_old_data_activity);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.old_data_activity, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
DatabaseHandler.java
package com.example.crudexamplerepeat;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.List;
import android.R.array;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.DatabaseErrorHandler;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DB_VERSION = 4;
private static final String DB_NAME = "usersInfo";
private static final String TABLE_NAME = "users";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PASS = "pass";
private static final String KEY_IMG = "pic";
public DatabaseHandler(Context context) {
super(context, DB_NAME, null, DB_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "(" + KEY_ID
+ " INTEGER PRIMARY KEY, " + KEY_NAME + " TEXT, " + KEY_PASS
+ " TEXT, " + KEY_IMG + " BLOB NOT NULL)";
db.execSQL(CREATE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public void addNewUser(UserGetSet userGetSet) {
// TODO Auto-generated method stub
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, userGetSet.getName());
values.put(KEY_PASS, userGetSet.getPass());
values.put(KEY_IMG, userGetSet.getImage());
db.insert(TABLE_NAME, null, values);
db.close();
}
public List<UserGetSet> getAllUsers() {
List<UserGetSet> userList = new ArrayList<UserGetSet>();
String selectQuery = "SELECT * FROM " + TABLE_NAME;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst())
{
do
{
UserGetSet userGetSetobj = new UserGetSet();
userGetSetobj.setName(cursor.getString(cursor.getColumnIndex(KEY_NAME)));
userGetSetobj.setPass(cursor.getString(cursor.getColumnIndex(KEY_PASS)));
userGetSetobj.setImage(cursor.getBlob(cursor.getColumnIndex(KEY_IMG)));
userList.add(userGetSetobj);
} while (cursor.moveToNext());
}
return userList;
}
}
package com.example.crudexamplerepeat;
导入java.lang.reflect.Array;
导入java.util.ArrayList;
导入java.util.List;
导入android.R.array;
导入android.content.ContentValues;
导入android.content.Context;
导入android.database.Cursor;
导入android.database.DatabaseErrorHandler;
导入android.database.sqlite.SQLiteDatabase;
导入android.database.sqlite.SQLiteDatabase.CursorFactory;
导入android.database.sqlite.SQLiteOpenHelper;
公共类DatabaseHandler扩展了SQLiteOpenHelper{
私有静态最终int DB_版本=4;
私有静态最终字符串DB_NAME=“usersInfo”;
私有静态最终字符串表\u NAME=“users”;
私有静态最终字符串密钥\u ID=“ID”;
私有静态最终字符串键\u NAME=“NAME”;
私有静态最终字符串密钥\u PASS=“PASS”;
私有静态最终字符串密钥\u IMG=“pic”;
公共数据库处理程序(上下文){
super(上下文,数据库名称,空,数据库版本);
//TODO自动生成的构造函数存根
}
@凌驾
public void onCreate(SQLiteDatabase db){
//TODO自动生成的方法存根
字符串CREATE_TABLE=“CREATE TABLE”+表名+”(“+KEY\u ID
+“整型主键,”+键名+“文本,”+键传递
+“文本,”+KEY_IMG+“BLOB NOT NULL)”;
db.execSQL(创建_表);
}
@凌驾
public void onUpgrade(SQLiteDatabase db,int-oldVersion,int-newVersion){
//TODO自动生成的方法存根
db.execSQL(“如果存在删除表”+表名称);
onCreate(db);
}
public void addNewUser(UserGetSet UserGetSet){
//TODO自动生成的方法存根
SQLiteDatabase db=this.getWritableDatabase();
ContentValues=新的ContentValues();
value.put(KEY_NAME,userGetSet.getName());
value.put(KEY_PASS,userGetSet.getPass());
value.put(KEY_IMG,userGetSet.getImage());
db.insert(表名称,空,值);
db.close();
}
公共列表getAllUsers(){
List userList=new ArrayList();
String selectQuery=“SELECT*FROM”+表格名称;
SQLiteDatabase db=this.getWritableDatabase();
Cursor Cursor=db.rawQuery(selectQuery,null);
if(cursor.moveToFirst())
{
做
{
UserGetSet userGetSetobj=新的UserGetSet();
userGetSetobj.setName(cursor.getString(cursor.getColumnIndex(KEY_NAME));
userGetSetobj.setPass(cursor.getString(cursor.getColumnIndex(KEY_PASS));
userGetSetobj.setImage(cursor.getBlob(cursor.getColumnIndex(KEY_IMG));
添加(userGetSetobj);
}while(cursor.moveToNext());
}
返回用户列表;
}
}
UserListCustomAdapter.java
package com.example.crudexamplerepeat;
import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class UserListCustomAdapter extends BaseAdapter {
Context context;
protected List<UserGetSet> listUsers;
LayoutInflater inflater;
public UserListCustomAdapter(Context context, List<UserGetSet> listUsers) {
// TODO Auto-generated constructor stub
super();
this.listUsers = listUsers;
this.inflater = LayoutInflater.from(context);
this.context = context;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return listUsers.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return listUsers.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return listUsers.get(position).getUserId();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
// TODO Auto-generated method stub
ViewHolder viewHolder = new ViewHolder();
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.user_list_view, null);
TextView name = (TextView) v.findViewById(R.id.txt_data_name);
TextView pass = (TextView) v.findViewById(R.id.txt_data_pass);
ImageView photo = (ImageView) v.findViewById(R.id.img_photo);
viewHolder.txt_name = name;
viewHolder.txt_pass = pass;
viewHolder.img_pic = photo;
v.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) v.getTag();
}
UserGetSet uGetSet = listUsers.get(position);
viewHolder.txt_name.setText(uGetSet.getName());
viewHolder.txt_pass.setText(uGetSet.getPass());
viewHolder.img_pic.setImageResource(uGetSet.getUserId());
return convertView;
}
private class ViewHolder {
TextView txt_name;
TextView txt_pass;
ImageView img_pic;
}
}
package com.example.crudexamplerepeat;
导入java.util.List;
导入android.content.Context;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.BaseAdapter;
导入android.widget.ImageView;
导入android.widget.TextView;
公共类UserListCustomAdapter扩展了BaseAdapter{
语境;
受保护的列表用户;
充气机;
公共用户ListCustomAdapter(上下文上下文,列表用户){
//TODO自动生成的构造函数存根
超级();
this.listUsers=listUsers;
this.inflater=layoutiner.from(上下文);
this.context=上下文;
}
@凌驾
public int getCount(){
//TODO自动生成的方法存根
返回listUsers.size();
}
@凌驾
公共对象getItem(int位置){
//TODO自动生成的方法存根
返回listUsers.get(位置);
}
@凌驾
公共长getItemId(int位置){
//TODO自动生成的方法存根
返回listUsers.get(position.getUserId();
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
视图v=转换视图;
//TODO自动生成的方法存根
ViewHolder ViewHolder=新ViewHolder();
if(convertView==null){
LayoutFlater充气器=(LayoutFlater)上下文
.getSystemService(上下文布局\充气机\服务);
v=充气机充气(R.layout.user\u list\u视图,空);
TextView名称=(TextView)v.findviewbyd(R.id.txt\u数据\u名称);
TextView pass=(TextView)v.findViewById(R.id.txt\u data\u pass);
ImageView照片=(ImageView)v.findViewById(R.id.img_照片);
viewHolder.txt_name=名称;
viewHolder.txt_pass=pass;
viewHolder.img_pic=照片;
v、 setTag(视图持有者);
}否则{
viewHolder=(viewHolder)v.getTag();
}
UserGetSet-uGetSet=listUsers.get(位置);
viewHolder.txt_name.setText(uGetSet.getName());
viewHolder.txt_pass.setText(uGetSet.getPass());
viewHolder.img_pic.setImageResource(uGetSet.getUserId());
返回视图;
}
私有类视窗持有者{
TextView txt_名称;
TextView txt_pass;
图像视图图像;
}
}
在将博客数据设置为图像视图之前,必须先转换博客数据
byte[] byteArray = DBcursor.getBlob(columnIndex);
Bitmap bm = BitmapFactory.decodeByteArray(byteArray, 0 ,byteArray.length);
现在,您可以将位图设置为图像视图。我们不需要在db中存储图像字节,只需将该图像的Uri存储到db中,然后获取该Uri并在imageView上进行设置
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
imageView.setImageBitmap(bitmap);
我希望它能帮助您您为什么要存储