我正在开发一个症状检查器应用程序。我的应用程序有一个listview带复选框（来自android.R.layout.simple_list_item_multiple_choice）。
在检查以下症状并单击完成按钮后，应用程序应显示用户可能遇到的情况。信息已经存储在我预先填充的SQLite数据库中。有关您的信息，请参阅此屏幕截图：
这是我到目前为止所拥有的：（Symbols.java）
public void onClick(View v) {
// TODO Auto-generated method stub
/*Intent i = new Intent(this, SymptomsResult.class);
startActivity(i);
finish();*/
dbHelper = new DBHelper(this);
dbHelper.openDataBase();
String c = dbHelper.getData();
String selected = "";
int cntChoice = lv.getCount();
SparseBooleanArray sparseBooleanArray = lv.getCheckedItemPositions();
for(int i = 0; i < cntChoice; i++){
if(sparseBooleanArray.get(i)) {
selected += lv.getItemAtPosition(i).toString() + "\n";
}
}
c.equals(selected);
dbHelper.close();
Toast.makeText(this, selected, Toast.LENGTH_LONG).show();
}
DBHelper.java
public class DBHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.fps.myheartfirst/databases/";
private static String DB_NAME = "mhfDB";
private static String KEY_CONDITIONS = "conditions";
private static String KEY_SYMPTOMS = "symptoms";
private static String DB_TABLE = "tblSymptoms";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public DBHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
myDataBase = null;
if (dbExist) {
// do nothing - database already exist
} else {
// By calling this method and empty database will be created into
// the default system path
myDataBase = this.getReadableDatabase();
myDataBase.close();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database doesn't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS | SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public String getData() {
String search = "";
Cursor c = myDataBase.rawQuery("SELECT " + KEY_CONDITIONS + " FROM " + DB_TABLE +
" WHERE " + KEY_SYMPTOMS + " = '"
+ search + "'", null);
//new String[] { name }, null, null, null);
int iRow = c.getColumnIndex(KEY_CONDITIONS);
for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
search = search + c.getString(iRow);
}
return search;
}
我的问题是，如何为我的症状类放置字符串查询？我对数据库编程有点陌生，所以请原谅。
我相信在这一行中，我必须说些什么：
c.equals(selected);
dbHelper.close();
Toast.makeText(this, selected, Toast.LENGTH_LONG).show();
因此，将向用户显示 toast 以查看可能的条件。这里有人知道如何做到这一点吗？我会很感激你的帮助。谢谢。