Android学习笔记——Button

1.工程的功能是实现在一个acticity上点击按钮，切换到另外一个activity

 

以下代码为MainActivity.java中的代码

package com.example.button_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;

public class MainActivity extends Activity {

    private Button myButton = null; 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myButton = (Button)findViewById(R.id.myButton);
        myButton.setOnClickListener(new MyButtonListener());  
    }
    
    class MyButtonListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
        Intent intent = new Intent();
        intent.setClass(MainActivity.this, OtherActivity.class);
        MainActivity.this.startActivity(intent);
        }
        
        
    }
        
}

 

以下代码为OtherActivity.java中的代码

package com.example.button_activity;

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

public class OtherActivity extends Activity{

    private TextView myTextView = null; 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_other);
        myTextView = (TextView)findViewById(R.id.myTextView);
        myTextView.setText(R.string.other);
    }
    

}

 

以下代码为activity_main.xml中的代码

<RelativeLayout xmlns:andro>
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <Button
        android:>
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        
        />

</RelativeLayout>

 

以下代码为activity_other.xml中的代码

<RelativeLayout xmlns:andro>
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:>
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    

</RelativeLayout>

 

以下代码为string.xml中的代码

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">button_activity</string>
    <string name="hello_world">Hello world!</string>
    <string name="other">OtherActivity</string>
</resources>

 

以下代码为AndroidManifest.xml中的代码 

注意修改package的名称

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:andro
    package="com.example.button_activity"
    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=".OtherActivity"
            android:label="@string/other" >
        </activity>     
    </application>

</manifest>

 

如果不能运行请kill-adb和start-adb并重新启动eclipse

 

2.该工程的功能是实现在activity中显示一个TextView和一个Button

以下代码是MainActivity中的代码

package com.example.button;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView myTextView = (TextView)findViewById(R.id.myTextView);
        Button myButton = (Button)findViewById(R.id.myButton);
        myTextView.setText("我的第一个TextView");
        myButton.setText("我的第一个Button");
        
    }
}

 

以下代码是activity_main中的代码

<RelativeLayout xmlns:andro>
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/myTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <Button
        android:id="@+id/myButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />

</RelativeLayout>