Android学习历程-Android常用控件（简单计算器）

两个布局文件：

<?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/numOne"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:inputType="text" />

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

    <EditText
        android:id="@+id/numTwo"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:inputType="text" />

    <Button
        android:id="@+id/calculate"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        />

</LinearLayout>

 

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

</LinearLayout>

 

两个Activity:

package com.may.activity;

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 Activity04 extends Activity {

 private EditText numOne = null;
 private EditText numTwo = null;
 private TextView symbol = null;
 private Button  calculate = null;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity04);
  numOne=(EditText)findViewById(R.id.numOne);
  numTwo=(EditText)findViewById(R.id.numTwo);
  symbol=(TextView)findViewById(R.id.symbol);
  calculate=(Button)findViewById(R.id.calculate);
  
  //为symbol
  symbol.setText("乘以");
  calculate.setText("计算");
  calculate.setOnClickListener(new CalculateListener());
 }

 
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  menu.add(0, 1, 1, R.string.exit);
  menu.add(0, 2, 2, R.string.about);
  return super.onCreateOptionsMenu(menu);
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  if(item.getItemId()==1){
   finish();
  }else if(item.getItemId()==2){
   
  }
  return super.onOptionsItemSelected(item);
 }

 class CalculateListener implements OnClickListener{

  @Override
  public void onClick(View v) {
   String numOneStr = numOne.getText().toString().trim();
   String numTwoStr = numTwo.getText().toString().trim();
   Intent inten = new Intent();
   inten.putExtra("one", numOneStr);
   inten.putExtra("two", numTwoStr);
   inten.setClass(Activity04.this, Activity05.class);
   Activity04.this.startActivity(inten);
  }
  
 }
}

 

package com.may.activity;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class Activity05 extends Activity {

	private TextView resultTextView = null;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity05);
		resultTextView = (TextView) findViewById(R.id.resultTextView);
		Intent intent = getIntent();
		int numOne = Integer.valueOf(intent.getStringExtra("one"));
		int numTwo = Integer.valueOf(intent.getStringExtra("two"));
		int resultValue = numOne * numTwo;
		resultTextView.setText(resultValue+"");
	}

}

 在AndroidMainfest添加：

        <activity
            android:name="com.may.activity.Activity04"
            android:label="sub" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.may.activity.Activity05"
            android:label="result" >
        </activity>