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CSIS 3175 Mobile Cheat Sheet by

Decimal Format

DecimalFormat currency = new DecimalFormat("$###,###.##");  
currency.format(totalCost));

Pass And Get Value Into/From Another Activity

Intent i = new Intent(MainActivity.this,
                                SecondActivity.class);
                        i.putExtra("data",totalCost);
                        startActivity(i);

Intent intent = getIntent();
Double value = itent.getDoubleExtra(Key,0);

Splash Activity

public class SplashActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                finish();
                startActivity(new Intent(SplashActivity.this,
                        MainActivity.class));
            }
        };
        Timer t = new Timer();
        t.schedule(task,4000);
    }
}

Working with Files

FileOutputStream fout =
		openFileOutput("File1.txt",MODE_APPEND);
fout.write(data.getBytes());
fout.write("\n".getBytes());
fout.close();
FileInputStream fin = openFileInput("File1.txt");
String temp = "";
int c;
char ch;
while((c=fin.read())!=-1){
	ch = (char)c;
	temp += Character.toString(ch);
}
output.setText(temp);
fin.close();

Calling DBHelper

//to view student records
/*Cursor c = dbh.viewData();
StringBuilder str = new StringBuilder();
if(c.getCount()>0){
	while (c.moveToNext()){
		str.append("ID : " +c.getString(0));
		str.append(" First Name : " +c.getString(1));
		str.append(" Last Name : "+c.getString(2));
		str.append(" Cell number : "+ c.getString(3));
		str.append(" prov Id : " + c.getString(4));
		str.append("\n");
	}
	result.setText(str);

//Create Record
 boolean isAdded= db.addRec(fn.getText().toString(),ln.getText().toString(),
                        cn.getText().toString(),pi.getText().toString());

Database

public class DatabaseHelper extends SQLiteOpenHelper{
final static String DATABASE_NAME = "Information.db";
final static int DATABASE_VERSION = 4;

public DatabaseHelper(Context context) {
	super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
	//creating student_table and province_table
	String query = "Create Table [TABLENAME] ( [COLUMN] INTEGER PRIMARY KEY ,COLUMN2 TEXT,...)"; 
	//Only INTEGER, TEXT OR REAL
	try{
		db.execSQL(query);
	}
	catch (Exception e){
		e.printStackTrace();
	}
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
	db.execSQL("Drop table if exists " + TABLE1_NAME);
	db.execSQL("Drop table if exists " + TABLE2_NAME);
	onCreate(db);
}

//Add Record
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("Column",value);
long r = db.insert(TABLE1_NAME,null,values);
if(r == -1){
	return  false;
}
else{
	return true;
}

//method to view data
public Cursor viewData(){
	SQLiteDatabase db = this.getWritableDatabase();
	String query = "Select * from " + TABLE1_NAME;
	Cursor c = db.rawQuery(query,null);
	return c;
}
 

Play Media

mpG = new MediaPlayer();
mpG = MediaPlayer.create(this,R.raw.ukulele);
mpD = new MediaPlayer();
mpD = MediaPlayer.create(this,R.raw.drums);
mpG.start();
mpG.pauset();

Shared Prefs

final SharedPreferences sharedPref =
                PreferenceManager.getDefaultSharedPreferences
                        (this);

button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                intYear = Integer.parseInt(years.getText().toString());
                decLoan = Float.parseFloat(loan.getText().toString());
                decInterest = Float.parseFloat(interest.getText().toString());
                SharedPreferences.Editor editor = sharedPref.edit();
                editor.putInt("key1",intYear);
                editor.putFloat("key2",decLoan);
                editor.putFloat("key3",decInterest);
                editor.commit();
                startActivity(new Intent
                        (MainActivity.this,Payment.class));
            }
        });


//Get the values
SharedPreferences sp = PreferenceManager.
                getDefaultSharedPreferences(this);

 int years = sp.getInt("key1",0);
 float loan = sp.getFloat("key2",0);
float interest = sp.getFloat("key3",0);

Working With Fragments

public class FragmentOne extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_fragment_one, container, false);
    }
//Main
public void clickOne(View view){
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        FragmentOne f1 = new FragmentOne();
        ft.add(R.id.rlFrag1,f1);
        ft.commit();
    }
//Add this to the layout
android:onClick="clickOne"
//Dont forget to change fragment layout to relative
 

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