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"/>