Android写一个简单乘法计算

第六讲? Android当中的常见控件

TextView的使用方法

EditText的使用方法

Button的使用方法

Menu的使用方法

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Activity03.java?

package com.test.app;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;/*

1、在Activity03当中，要声明四个控件2、要为其中的两个控件设置显示的值。3、创建一个监听器类。监听按钮按下的动作。4、将监听器类的对象，绑定在按钮对象上。

*/public class Activity03 extends Activity {    /** Called when the activity is first created. */private EditText editTextOne;private TextView textView;private EditText editTextTwo;private Button button;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                editTextOne=(EditText)findViewById(R.id.MyOne);        textView=(TextView)findViewById(R.id.MyTextView);        editTextTwo=(EditText)findViewById(R.id.MyTwo);        button=(Button)findViewById(R.id.MyButton);        textView.setText(R.string.fh);        button.setText("计算");        button.setOnClickListener(new CalListener());    }        class CalListener implements OnClickListener{@Overridepublic void onClick(View v) {// TODO Auto-generated method stubString oneStr = editTextOne.getText().toString();String twoStr = editTextTwo.getText().toString();Intent intent= new Intent();intent.putExtra("first", oneStr);intent.putExtra("second", twoStr);intent.setClass(Activity03.this, CalActivity.class);startActivity(intent);}            }}

?取得两EditText控件的值
将这两个值存放到Intent对象当中
使用这个Intent对象来启动ResultActivity

CalActivity

1、接受从Activity03当中所传递的值
2、计算两个值 的积
3、计算的结果显示在Activity

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CalActivity.java

package com.test.app;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.widget.TextView;public class CalActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.cal);TextView textView = (TextView)findViewById(R.id.MyCal);Intent intent = getIntent();      //得到传递过来的Intent。String one = intent.getStringExtra("first");     //从Intent中取出相应的键值。String two = intent.getStringExtra("second");if(one != null && two !=null){int firstOne= Integer.parseInt(one);int secondTwo = Integer.parseInt(two);int result = firstOne*secondTwo;textView.setText(result+"");}else{textView.setText("传递过来的值为空！");}}}

AndroidManifest.xml

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<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"      package="com.test.app"      android:versionCode="1"      android:versionName="1.0">    <application android:icon="@drawable/icon" android:label="@string/app_name">        <activity android:name=".Activity03"                  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=".CalActivity"            android:label="@string/calActivity">                        <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application>    <uses-sdk android:minSdkVersion="8" /></manifest> 

?main.xml

<?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"    ><EditText  android:id="@+id/MyOne"  android:layout_width="fill_parent"  android:layout_height="wrap_content"/><TextView      android:id="@+id/MyTextView"    android:layout_width="fill_parent"     android:layout_height="wrap_content"  />  <EditText  android:id="@+id/MyTwo"  android:layout_width="fill_parent"  android:layout_height="wrap_content"/><Button   android:id="@+id/MyButton"  android:layout_width="fill_parent"  android:layout_height="wrap_content"  /></LinearLayout>

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cal.xml

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<?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/MyCal"    android:layout_width="wrap_content"     android:layout_height="wrap_content"  /> </LinearLayout>

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