Technology Lesson

<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=".MainActivity" >

<TextView
    android:id="@+id/text"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

<GridView 
    android:id="@+id/grid"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:verticalSpacing="35dp"
    android:horizontalSpacing="5dp"
    android:numColumns="auto_fit"
    android:columnWidth="100dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
    />
    
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Code For Food Test</string>
    <string name="menu_settings">Settings</string>
    <string-array name="choices_array">
        <item>One</item>
        <item>Two</item>
        <item>Three</item>
        <item>Four</item>
        <item>Five</item>
        <item>Seven</item>
        <item>Eight</item>
        <item>Nine</item>
        <item>Ten</item>
    </string-array>

</resources>

public class MainActivity extends Activity implements OnItemClickListener{

private TextView text;
private GridView grid;

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

grid = (GridView)findViewById(R.id.grid);
text = (TextView)findViewById(R.id.text);

String[] choices = getResources().getStringArray(R.array.choices_array);

ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, choices);
grid.setAdapter(arrayAdapter);
grid.setOnItemClickListener(this);
}

public void onItemClick(AdapterView<?> parent, View view, int pos, long id) {
    text.setText("The selected item is " + parent.getItemAtPosition(pos).toString());
    }

package com.kircode.codeforfood_test;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.TextView;

public class MainActivity extends Activity implements OnItemClickListener{

private TextView text;
private GridView grid;

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

grid = (GridView)findViewById(R.id.grid);
text = (TextView)findViewById(R.id.text);

String[] choices = getResources().getStringArray(R.array.choices_array);

ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, choices);
grid.setAdapter(arrayAdapter);
grid.setOnItemClickListener(this);
}

public void onItemClick(AdapterView<?> parent, View view, int pos, long id) {
    text.setText("The selected item is " + parent.getItemAtPosition(pos).toString());
    }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}

}

<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=".MainActivity" >
    
    <TextView android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="32sp"
        android:text="First Activity"
        />

    <Button android:id="@+id/goButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Launch Second Activity"
        />
    
</LinearLayout>

private static final int IDM_TEST = 101;

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

final Button btn = (Button)findViewById(R.id.goButton);
btn.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setClass(getApplicationContext(), SecondActivity.class);
startActivityForResult(intent, IDM_TEST);
}
});
}

protected void onActivityResult(int requestCode, int resultCode, Intent data){
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK){
Bundle extras = data.getExtras();
// handle results
if(requestCode == IDM_TEST){
Toast toast = Toast.makeText(MainActivity.this, extras.getString("UserText"), Toast.LENGTH_SHORT);
toast.show();
}
}
}

package com.kircode.codeforfood_test;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity{

private static final int IDM_TEST = 101;

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

final Button btn = (Button)findViewById(R.id.goButton);
btn.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setClass(getApplicationContext(), SecondActivity.class);
startActivityForResult(intent, IDM_TEST);
}
});
}

protected void onActivityResult(int requestCode, int resultCode, Intent data){
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK){
Bundle extras = data.getExtras();
// handle results
if(requestCode == IDM_TEST){
Toast toast = Toast.makeText(MainActivity.this, extras.getString("UserText"), Toast.LENGTH_SHORT);
toast.show();
}
}
}

}

<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=".MainActivity" >
    
    <TextView android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="32sp"
        android:text="Second Activity"
        />
    
    <EditText android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Write something here..."
        android:id="@+id/editText"
        />
    
    <Button android:id="@+id/backButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="OK"
        />
    
</LinearLayout>

package com.kircode.codeforfood_test;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class SecondActivity extends Activity{


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

final Button btn = (Button)findViewById(R.id.backButton);
btn.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
EditText text = (EditText)findViewById(R.id.editText);

Intent intent = new Intent();
intent.putExtra("UserText", text.getText().toString());
setResult(RESULT_OK, intent);
finish();
}
});
}

}

        <provider 
            android:name="com.kircode.codeforfood_test.myContentProvider"
            android:authorities="com.kircode.codeforfood_test.contactprovider">
        </provider>

String[] columns = new String[] {myDbHelper.NAME, myDbHelper.PHONE};
ContentResolver resolver = getContentResolver();
Cursor cursor = resolver.query(CONTENT_URI, columns, null, null, null);

<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=".MainActivity" >

<Button
    android:id="@+id/testButton"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Call an AlertDialog"
    />
    
</LinearLayout>

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);

builder.setTitle("Exit application");
builder.setMessage("Do you want to exit?");

builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
MainActivity.this.finish();
}
});

builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});

builder.setCancelable(false);

AlertDialog myDialog = builder.create();
myDialog.show();

package com.kircode.codeforfood_test;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity{

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

Button button = (Button)findViewById(R.id.testButton);

button.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Exit application");
builder.setMessage("Do you want to exit?");
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
MainActivity.this.finish();
}
});

builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});

builder.setCancelable(false);
AlertDialog myDialog = builder.create();
myDialog.show();
}
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}

}