[Lesson 3] ความสัมพันธ์ของ Layout และโค้ด Java ในการเขียน Android ... อ่านรีวิวต่อได้ที่ http://review.thaiware.com/435-Lesson-3-Layout-Java-Android.html

activity_main.xml

<RelativeLayout 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"
    tools:context=".MainActivity" >

    <LinearLayout 
        android:layout_width="fill_parent"
      android:layout_height="fill_parent"
	    android:orientation="vertical" >
	    
	    <LinearLayout 
	        android:layout_width="fill_parent"
		    android:layout_height="wrap_content"
		    android:layout_margin="10dp"
		    android:orientation="vertical" >
		     
		    <TextView
		        android:id="@+id/topText"
		        android:layout_width="wrap_content"
		        android:layout_height="wrap_content"
		        android:layout_gravity="center"
		        android:textStyle="bold"
		        android:text="@string/main_text" />
		</LinearLayout>
	    
	    <LinearLayout 
				    android:layout_width="fill_parent"
				    android:layout_height="wrap_content"
				    android:orientation="horizontal" 
				    android:layout_marginLeft="5dp"
				    android:layout_marginRight="5dp" >
			 <TextView
			        android:layout_width="wrap_content"
			        android:layout_height="wrap_content"
			        android:layout_margin="5dp"
			        android:text="Name: " />
			 <EditText 
					android:id="@+id/editName"
					android:layout_width="fill_parent"
					android:layout_height="wrap_content"
					android:layout_marginLeft="5dp"	 />
		</LinearLayout>
		
	    <LinearLayout 
				    android:layout_width="fill_parent"
				    android:layout_height="wrap_content"
				    android:orientation="horizontal" 
				    android:layout_marginLeft="5dp"
				    android:layout_marginRight="5dp" >
			 <TextView
			        android:layout_width="wrap_content"
			        android:layout_height="wrap_content"
			        android:layout_margin="5dp"
			        android:text="Surname: " />
			 <EditText 
					android:id="@+id/editSurname"
					android:layout_width="fill_parent"
					android:layout_height="wrap_content"
					android:layout_marginLeft="5dp"	 />
		</LinearLayout>
	    
	    <LinearLayout 
				    android:layout_width="fill_parent"
				    android:layout_height="wrap_content"
				    android:orientation="horizontal" 
				    android:layout_marginLeft="5dp"
				    android:layout_marginRight="5dp" >
			 <TextView
			        android:layout_width="wrap_content"
			        android:layout_height="wrap_content"
			        android:layout_margin="5dp"
			        android:text="Email: " />
			 <EditText 
					android:id="@+id/editEmail"
					android:layout_width="fill_parent"
					android:layout_height="wrap_content"
					android:layout_marginLeft="5dp"	 />
		</LinearLayout>
	    
	    <LinearLayout 
				    android:layout_width="fill_parent"
				    android:layout_height="wrap_content"
				    android:orientation="horizontal" 
				    android:layout_marginLeft="5dp"
				    android:layout_marginRight="5dp" >
			 <TextView
			        android:layout_width="wrap_content"
			        android:layout_height="wrap_content"
			        android:layout_margin="5dp"
			        android:text="Tel: " />
			 <EditText 
					android:id="@+id/editTel"
					android:layout_width="fill_parent"
					android:layout_height="wrap_content"
					android:layout_marginLeft="5dp"	 />
		</LinearLayout>
		
	    <LinearLayout 
			    android:layout_width="fill_parent"
			    android:layout_height="wrap_content"
			    android:orientation="horizontal" 
			    android:layout_marginTop="10dp"
			    android:gravity="center" >
			    	<Button 
			    	    android:layout_width="wrap_content"
			    	    android:layout_height="wrap_content"
			    	    android:text="Done"
			    	    android:id="@+id/doneMember"/>
			    	<Button 
			    	    android:layout_width="wrap_content"
			    	    android:layout_height="wrap_content"
			    	    android:text="Clear"
			    	    android:id="@+id/clearMember"/>
			</LinearLayout>
	    
	    <LinearLayout 
				    android:layout_width="fill_parent"
				    android:layout_height="wrap_content"
				    android:orientation="horizontal" 
				    android:layout_marginLeft="5dp"
				    android:layout_marginRight="5dp" >
			    	
	        		<TextView
				        android:layout_width="wrap_content"
				        android:layout_height="wrap_content"
				        android:text="Result: " />
	        		
	        		<TextView
				        android:layout_width="wrap_content"
				        android:layout_height="wrap_content"
				        android:id="@+id/showResult"/>
		
		  </LinearLayout>
		
    </LinearLayout>
    
</RelativeLayout>

MainActivity.java

package com.thaiware.codetesting;

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

	//Declare Widgets
	EditText fieldName, fieldSurname, fieldEmail, fieldTel;
	TextView fieldText;
	Button btnDone, btnClear;	
	String showName = "";
	String showSurname, showEmail, showTel;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		//Reference with layout file that is "activity_main.xml"
		fieldName = (EditText) findViewById(R.id.editName);
		fieldSurname = (EditText) findViewById(R.id.editSurname);
		fieldEmail = (EditText) findViewById(R.id.editEmail);
		fieldTel = (EditText) findViewById(R.id.editTel);
		
		fieldText = (TextView) findViewById(R.id.showResult);
				
		btnDone = (Button) findViewById(R.id.doneMember);
		
		//Set event to button "Done"
		btnDone.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				if(fieldName.getText().toString().equals("")){
					//Display alertdialog
					AlertDialog.Builder alert = new AlertDialog.Builder(MainActivity.this);
					alert.setIcon(android.R.drawable.ic_dialog_alert);
					alert.setTitle("Please insert your information !");
				    alert.setPositiveButton("OK",
				    		new DialogInterface.OnClickListener() {
				            	public void onClick(DialogInterface dialog, int which) {
				            		dialog.dismiss();
				                }
				        	}).show();
				}else{
					//Get text from EditText
					showName = fieldName.getText().toString();
					showSurname = fieldSurname.getText().toString();
					showEmail = fieldEmail.getText().toString();
					showTel = fieldTel.getText().toString();
					
					//Display result of input
					fieldText.setText(showName +" "+ showSurname +"\n"+ showEmail+"\n"+showTel);
					Toast.makeText(getBaseContext(), "Insert "+ "'"+showName+"'" +" Succeed.", Toast.LENGTH_SHORT).show();
					
					//Clear EditText after preess Done button
					fieldName.setText("");
					fieldSurname.setText("");
					fieldEmail.setText("");
					fieldTel.setText("");
				}
			}
		});
		//Clear EditText if user presses "Clear" button
		btnClear = (Button) findViewById(R.id.clearMember); 
		btnClear.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				fieldName.setText("");
				fieldSurname.setText("");
				fieldEmail.setText("");
				fieldTel.setText("");
				fieldText.setText("");
				Toast.makeText(getBaseContext(), "Clear Succeed.", Toast.LENGTH_SHORT).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;
	}

}

strings.xml

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

    <string name="app_name">First App Ja</string>
    <string name="menu_settings">Settings</string>
    <string name="main_text">Member System Testing</string>

</resources>