我正在尝试使用blob将图像插入sqlite数据库我不想将图像存储在存储卡中并从中读取因为我不希望用户有权访问它。我在表中有一行名为image。数据来自mysql数据库
package com.mall.our;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import android.content.ContentValues;
import android.content.Context;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.preference.PreferenceManager;
import android.util.Log;
public class DBTool extends SQLiteOpenHelper {
private Context appContext;
static final String firstname="firstname";
static final String lastname="lastname";
public DBTool(Context applicationContext){
super(applicationContext, "friend.db", null, 1);
this.appContext = applicationContext;
}
@Override
public void onCreate(SQLiteDatabase database) {
String query = "CREATE TABLE friends ( contactId INTEGER PRIMARY KEY, name TEXT, " +
"message TEXT, image BLOB)";
database.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
String query = "DROP TABLE IF EXISTS friends";
database.execSQL(query);
onCreate(database);
}
public void insertContact(HashMap<String, String> queryValues){
SQLiteDatabase database = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", queryValues.get("name"));
values.put("message", queryValues.get("message"));
values.put("image", queryValues.get("image"));
database.insert("friends", null, values);
database.close();
}
public ArrayList<HashMap<String, String>> getAllContacts(){
ArrayList<HashMap<String, String>> contactArrayList = new ArrayList<HashMap<String, String>>();
String selectQuery = "SELECT * FROM friends";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()){
do{
HashMap<String, String> contactMap = new HashMap<String, String>();
contactMap .put("name", cursor.getString(0));
contactMap .put("message", cursor.getString(1));
contactMap .put("image", cursor.getString(2));
contactArrayList.add(contactMap);
} while(cursor.moveToNext());
}
return contactArrayList;
}
public int updateContact(HashMap<String, String> queryValues){
SQLiteDatabase database = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", queryValues.get("name"));
values.put("message", queryValues.get("message"));
values.put("image", queryValues.get("image"));
return database.update("friends", values,
"contactId" + " = ?", new String[] {queryValues.get("contactId") });
}
public void deleteContact(){
SQLiteDatabase database = this.getWritableDatabase();
String deleteQuery = "DELETE FROM friends ";
database.execSQL(deleteQuery);
}
public HashMap<String, String> getContactInfo(String id){
HashMap<String, String> contactMap = new HashMap<String, String>();
SQLiteDatabase database = this.getReadableDatabase();
String selectQuery = "SELECT * FROM friends WHERE contactId='" + id + "'";
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()){
do{
contactMap.put("name", cursor.getString(0));
contactMap.put("message", cursor.getString(1));
contactMap.put("image", cursor.getString(2));
} while(cursor.moveToNext());
}
return contactMap;
}
}
这是我的另一个班级
package com.mall.our;
import java.io.IOException;
import java.net.URL;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.TextView;
import com.actionbarsherlock.app.SherlockListFragment;
import com.mall.first.JSONParser;
import com.mall.first.R;
public class Chat extends SherlockListFragment {
JSONParser jsonParser = new JSONParser();
private static final String TAG_POSTS = "posts";
public static final String TAG_ID = "id";
public static final String TAG_NAME = "name";
public static final String TAG_pic = "pic";
public static final String TAG_MESSAGE = "message";
public static final String TAG_CATEGORIES_LOGO = "categories_logo";
DBTool dbTool = new DBTool(getActivity());
/*
user details
private static final String NAME = "name";
private static final String AGE = "age";
private static final String STATUS = "status";
private static final String PIC = "pic";
private static final String SEX = "sex"; String friendname,status;
private static final String TAG_SUCCESS = "success";*/
//user
private static final String URL = "http://10.0.2.2/ochat/chattingname.php";
private static final String URL_CATEGORY = "http://10.0.2.2/ochat/selectchat.php";
private BaseAdapter mAdapter;
private ListView lv;
SharedPreferences sp ;
Bundle bon = new Bundle();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.friends, container, false);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
new LoadComments().execute();
}
class LoadComments extends AsyncTask<Void, Void, ArrayList<HashMap<String,String>>> {
private ProgressDialog pDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
}
@Override
protected ArrayList<HashMap<String, String>> doInBackground(Void... arg0) {
ArrayList<HashMap<String, String>> categoryList = new ArrayList<HashMap<String, String>>();
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
String username = sp.getString("username", "anon");
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", username));
JSONObject json = jsonParser.makeHttpRequest(URL_CATEGORY, "POST",
params);
try {
JSONArray categories = json.getJSONArray(TAG_POSTS);
for (int i = 0; i < categories.length(); i++) {
String id = categories.getJSONObject(i).getString("TAG_ID");
String name = categories.getJSONObject(i).getString("TAG_NAME");
String pic = categories.getJSONObject(i).getString("TAG_pic");
String message = categories.getJSONObject(i).getString("TAG_MESSAGE");
HashMap<String, String> queryValuesMap = new HashMap<String, String>();
queryValuesMap.put("name", name);
queryValuesMap.put("image", pic);
queryValuesMap.put("message",message);
dbTool.insertContact(queryValuesMap);
}
}catch (Throwable e){
e.printStackTrace();
}
return categoryList;
}
@Override
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
super.onPostExecute(result);
}
}
}
我的问题是如何转换 Chat.java 类中的“String pic”变量是图像的数组或网址。我如何将其转换为位图，以便我可以在表格中将其捕获？
答案 0 :(得分：0)
在此代码下方使用ArrayList，并将每个图像网址添加到此代码中。
ArrayList<String> list = new ArrayList<String>(); list.add(pic);
使用此代码将drawable转换为位图。
ByteArrayOutputStream baos = new ByteArrayOutputStream();
// converting drawable to bitmap
_bitmapToInsert = ((BitmapDrawable) getResources().getDrawable(
R.drawable.skholingua)).getBitmap();
// compressing bitmap
_bitmapToInsert.compress(Bitmap.CompressFormat.PNG, 100, baos);
// converting bitmap to byte array
_photoToInsert = baos.toByteArray();
// inserting into to database
_sqlLiteManger.insert(_photoToInsert);
更多信息：http://www.skholingua.com/android-basic/advance-topics/database-storage