Android学习笔记——menu
该工程的功能是实现两个数相乘，并在另外一个Activity中显示计算的结果
以下的代码是MainActivity.java中的代码
package com.example.menu; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class MainActivity extends Activity { private EditText factorOne; private EditText factorTwo; private TextView symbol; private Button calculate; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); factorOne = (EditText)findViewById(R.id.factorOne); factorTwo = (EditText)findViewById(R.id.factorTwo); symbol = (TextView)findViewById(R.id.symbol); calculate = (Button)findViewById(R.id.calculate); //symbol.setText("乘以"); //calculate.setText("计算"); //为symbol和calculate设置显示的值 symbol.setText(R.string.symbol); calculate.setText(R.string.calculate); //将监听器的对象绑定到按钮对象上面 calculate.setOnClickListener(new CalculateListener()); } @Override public boolean onCreateOptionsMenu(Menu menu) { // TODO Auto-generated method stub menu.add(0,1,1,R.string.exit); menu.add(0,2,2,R.string.about); return super.onCreateOptionsMenu(menu); } //当客户点击MENU按钮的时候，调用该方法 @Override public boolean onOptionsItemSelected(MenuItem item) { // TODO Auto-generated method stub if(item.getItemId() == 1){ finish(); } return super.onOptionsItemSelected(item); } class CalculateListener implements OnClickListener{ @Override public void onClick(View v) { // TODO Auto-generated method stub //取得两个EditText控件的值 String factorOneStr = factorOne.getText().toString(); String factorTwoStr = factorTwo.getText().toString(); //将这两个值存放到Intent对象当中 Intent intent = new Intent(); intent.putExtra("one",factorOneStr); intent.putExtra("two",factorTwoStr); intent.setClass(MainActivity.this,ResultActivity.class ); //使用这个Intent对象来启动ResultActivity MainActivity.this.startActivity(intent); } } }
以下的代码是ResultActivity.java中的代码
package com.example.menu; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.widget.TextView; public class ResultActivity extends Activity{ private TextView resultView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_result); resultView = (TextView)findViewById(R.id.result); //得到Intent对象当中的值 Intent intent = getIntent(); String factorOneStr = intent.getStringExtra("one"); String factorTwoStr = intent.getStringExtra("two"); int factorOneInt = Integer.parseInt(factorOneStr); int factorTwoInt = Integer.parseInt(factorTwoStr); //计算两个值的积 int result = factorOneInt * factorTwoInt; resultView.setText(result + ""); } }
以下的代码是activity_main.xml中的代码
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <EditText android:id="@+id/factorOne" 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" /> <EditText android:id="@+id/factorTwo" android:layout_width="fill_parent" android:layout_height="wrap_content" /> <Button android:id="@+id/calculate" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>
以下的代码是activity_result.xml中的代码
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:id="@+id/result" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>
以下的代码是string.xml中的代码
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">menu</string>
<string name="hello_world">Hello world!</string>
<string name="resultLabel">result</string>
<string name="symbol">乘法</string>
<string name="calculate">计算</string>
<string name="exit">退出</string>
<string name="about">关于</string>
</resources>
以下的代码是AndroidManifest.xml中的代码
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.menu"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name = ".ResultActivity">
</activity>
</application>
</manifest>