Android学习笔记-EditText&TextView&Button&菜单栏

界面文件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"     android:paddingBottom="@dimen/activity_vertical_margin"     android:paddingLeft="@dimen/activity_horizontal_margin"     android:paddingRight="@dimen/activity_horizontal_margin"     android:paddingTop="@dimen/activity_vertical_margin"     tools:context="com.example.activity_03.MainActivity" >     <EditText         android:id="@+id/factor_one"         android:layout_width="fill_parent"         android:layout_height="wrap_content" />     <TextView         android:id="@+id/symbol"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/factor_one" />     <EditText         android:id="@+id/factor_two"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/symbol" />     <Button         android:id="@+id/multiply"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/factor_two" /> </RelativeLayout>

界面文件result.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical" >      <TextView      android:id="@+id/result"     android:layout_width="fill_parent"     android:layout_height="wrap_content"     /> </LinearLayout>

MainActivity.java

public class MainActivity extends ActionBarActivity {	private EditText factor_one;	private EditText factor_two;	private TextView symbol;	private Button multiply;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);                  factor_one = (EditText) findViewById(R.id.factor_one);         factor_two = (EditText) findViewById(R.id.factor_two);         symbol = (TextView) findViewById(R.id.symbol);         multiply = (Button) findViewById(R.id.multiply);                  symbol.setText(R.string.symbol);         multiply.setText("计算");                  multiply.setOnClickListener(new OnClickListener() {	@Override	public void onClick(View v) {	// TODO Auto-generated method stub	String factor_one_str = factor_one.getText().toString();	String factor_two_str = factor_two.getText().toString();	Intent intent = new Intent();	intent.putExtra("factor_one_str", factor_one_str);	intent.putExtra("factor_two_str", factor_two_str);	intent.setClass(MainActivity.this, ResultActivity.class);	MainActivity.this.startActivity(intent);	}	});     }     @Override     public boolean onCreateOptionsMenu(Menu menu) {//设置菜单     	//MenuItem android.view.Menu.add(int groupId, int itemId, int order, int titleRes)     	menu.add(0, 1, 1, R.string.about);     	menu.add(0, 2, 2, R.string.exit);         return super.onCreateOptionsMenu(menu);     }          @Override     public boolean onOptionsItemSelected(MenuItem item) {//选中菜单选项之后进行的操作     	if (item.getItemId() == 1) {//关于	}else if (item.getItemId() == 2) {//退出	finish();	}     	return super.onOptionsItemSelected(item);     } }

ResultActivity.java

public class ResultActivity extends Activity{	private TextView result;	@Override	protected void onCreate(Bundle savedInstanceState) {	super.onCreate(savedInstanceState);	setContentView(R.layout.result);	String factor_one_str = getIntent().getStringExtra("factor_one_str");	String factor_two_str = getIntent().getStringExtra("factor_two_str");	int factor_one = Integer.parseInt(factor_one_str);	int factor_two = Integer.parseInt(factor_two_str);	result = (TextView) findViewById(R.id.result);	result.setText(factor_one * factor_two + "");	} }

strings.xml

<?xml version="1.0" encoding="utf-8"?> <resources>     <string name="app_name">Activity_03</string>     <string name="hello_world">Hello world!</string>     <string name="action_settings">Settings</string>     <string name="symbol">乘以</string>	<string name="exit">退出</string>	<string name="about">关于</string> </resources>

AndroidManifest.xml 中注册Activity

<activity android:name=".ResultActivity" android:label="ResultActivity"/>