Android SQLite Database Connnectivity

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.VideoView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void btnAddClick(View view) {

        EditText editText = (EditText)findViewById(R.id.etName);
        String strExpense = editText.getText().toString();
        SQLiteDatabase sqLiteDatabase = openOrCreateDatabase("ExpenseDB",  MODE_PRIVATE, null);

        String create = "CREATE Table IF NOT EXISTS Expenses (ExpenseId integer primary key autoincrement, ExpenseName varchar(40));";
        sqLiteDatabase.execSQL(create);

        String insert = "INSERT INTO Expenses (ExpenseName) values ('" + strExpense + "');";
        sqLiteDatabase.execSQL(insert);
        Toast.makeText(MainActivity.this, "Record Saved", Toast.LENGTH_SHORT).show();
        editText.setText("");

        }

    public void btnShowClick(View view) {
        SQLiteDatabase sqLiteDatabase = openOrCreateDatabase("ExpenseDB",  MODE_PRIVATE, null);

        String strSelect  = "select * from Expenses;";
        Cursor cursor = sqLiteDatabase.rawQuery(strSelect, null);
        TextView textView = (TextView)findViewById(R.id.tvExpense);
        if(cursor.getCount() > 0)
        {
            cursor.moveToFirst();
            do {
                String expense = cursor.getString(1);
                textView.setText(textView.getText() + "\n" + expense);
            }while (cursor.moveToNext());
        }
    }
}

Android WebView

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        WebView webView = (WebView)findViewById(R.id.webView);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("http://shalvinpd.blogspot.com");
    }

Android Style

colors.xml

<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>
    <color name="colorYellow">#FFFF00</color>
</resources>

styles.xml

 <style name="buttonStyle">
        <item name="android:background">@color/colorYellow</item>
    </style>

<Button
        style="@style/buttonStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello"
        android:id="@+id/button"
        android:layout_centerVertical="true"
        android:layout_alignParentStart="true" />

Android LinearLayout weight_sum and weight properties

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   android:orientation="vertical"
    tools:context="com.blogspot.shalvinpd.linearlayouteg.MainActivity"
    android:weightSum="2">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_weight="1"
        android:text="Hello World!"
        android:background="@color/colorPrimary"/>

    <TextView
        android:layout_width="match_parent"
        android:background="@color/colorAccent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Hello World!" />
</LinearLayout>