android学习日记（Android当中的常见控件）

Android当中的常见控件

TextView 在activity中显示 文本信息

EditText   可编辑文本框

Button

Menu

功能： 计算两个数乘积 和 menu中点退出键退出应用程序







MainActivity .java

package com.example.activity04;

import android.R.string;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences.Editor;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
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;
/*声明4个控件
* 控件设置显示值
* 创建一个监听器 监听按钮按下的动作
* 将监听器对象绑定在安扭上
*/
public class MainActivity extends Activity {
private EditText factorOne;
private EditText factorTwo;
private TextView symbol;
private Button getresult;

@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);
getresult = (Button)findViewById(R.id.getresult);
//设置显示的值
//symbol.setText("乘以");
//getresult.setText("计算");
symbol.setText(R.string.symbol);
getresult.setText(R.string.getresult);
class getresultListener implements OnClickListener{

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
//取两个EditText的值
String factorOnestr = factorOne.getText().toString();
String factorTwostr = factorTwo.getText().toString();

//将两个值放到Intent中
Intent intent =new Intent();
intent.putExtra("one",factorOnestr);
intent.putExtra("two",factorTwostr);
intent.setClass(MainActivity.this, ResultActivity.class);

//启动RestltActivity中
MainActivity.this.startActivity(intent);
}

}
//将监听器绑定到按钮
getresult.setOnClickListener(new  getresultListener());
getresult.setOnClickListener(new  getresultListener());

}

@Override
//当客户点击菜单中的某一个选项运行该方法
public boolean onOptionsItemSelected(MenuItem item) {
if(item.getItemId()==1){
finish();
}
// TODO Auto-generated method stub
return super.onOptionsItemSelected(item);
}

@Override
//当客户点击Menu时运行
public boolean onCreateOptionsMenu(Menu menu) {
menu.add(0,1,1,R.string.exit);
menu.add(0,2,2,R.string.about);
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

ResultActivity.java

package com.example.activity04;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
//接受intent的值
//计算两个数乘积
//显示
public class ResultActivity extends Activity{
private TextView reultView;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.result);
reultView=(TextView)findViewById(R.id.result);
//计算两个数乘积
Intent intent =getIntent();
String factorOnestr=intent.getStringExtra("one");
String factorTwostr=intent.getStringExtra("two");
int factorOneint=Integer.parseInt(factorOnestr);
int factorTwoint=Integer.parseInt(factorTwostr);
//计算结果
int result=factorOneint*factorTwoint;
reultView.setText(result+"");

}

}

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=".MainActivity" >

<EditText
android:id="@+id/factorOne"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/symbol"
android:layout_alignLeft="@+id/symbol"
android:layout_marginBottom="31dp"
android:ems="10" />

<EditText
android:id="@+id/factorTwo"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/getresult"
android:layout_centerHorizontal="true"
android:layout_marginBottom="73dp"
android:ems="10" >

<requestFocus />
</EditText>

<TextView
android:id="@+id/symbol"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/factorTwo"
android:layout_centerHorizontal="true"
/>

<Button
android:id="@+id/getresult"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/factorTwo"
android:layout_alignParentBottom="true"
android:layout_marginBottom="166dp" />

</RelativeLayout>

result.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=".MainActivity" >

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

</RelativeLayout>

string.xml

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

<string name="app_name">activity04</string>
<string name="action_settings">Settings</string>
<string name="hello_world">Hello world!</string>
<string name="symbol">乘以</string>
<string name="getresult">计算</string>
<string name="other">结果</string>
<string name="exit">退出</string>
<string name="about">关于</string>

</resources>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.activity04"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.activity04.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"
android:label="@string/other"
/>
</application>

</manifest>