android学习笔记10（activity的死亡，菜单，及对话框）
activity的死亡:在跳转时，加个finish()即可
对话框需要在manifest中配置，我找的好苦
First.java
package tk.myactivity06; import java.security.PublicKey; import android.os.Bundle; import android.app.Activity; import android.content.Intent; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class First extends Activity { private Button myButton=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.first); myButton=(Button)findViewById(R.id.first); myButton.setText(R.string.first); myButton.setOnClickListener(new FirstButtonListener()); } class FirstButtonListener implements OnClickListener{ @Override public void onClick(View v){ Intent intent=new Intent(); intent.setClass(First.this,Second.class ); First.this.startActivity(intent); finish(); } } //添加菜单 @Override public boolean onCreateOptionsMenu(Menu menu) { menu.add(0, 1, 1, R.string.exit ); menu.add(0, 2, 2, R.string.about); getMenuInflater().inflate(R.menu.first, menu); return true; } //菜单项处理 @Override public boolean onOptionsItemSelected(MenuItem item) { if(item.getItemId() == 1){ finish(); }else if(item.getItemId()==2){ Intent intent=new Intent(); intent.setClass(First.this,About.class ); First.this.startActivity(intent); } return super .onOptionsItemSelected(item); } }
first.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" > <Button android:id="@ id/first" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>
Second.java
package tk.myactivity06; import tk.myactivity06.First.FirstButtonListener; 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 Second extends Activity{ private Button myButton=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.second); myButton=(Button)findViewById(R.id.second); myButton.setText(R.string.second); myButton.setOnClickListener(new SecondButtonListener()); } class SecondButtonListener implements OnClickListener{ @Override public void onClick(View v){ Intent intent=new Intent(); intent.setClass(Second.this,Three.class ); Second.this.startActivity(intent); finish(); } } //添加菜单 @Override public boolean onCreateOptionsMenu(Menu menu) { menu.add(0, 1, 1, R.string.exit ); menu.add(0, 2, 2, R.string.about); getMenuInflater().inflate(R.menu.first, menu); return true; } //菜单项处理 @Override public boolean onOptionsItemSelected(MenuItem item) { if(item.getItemId() == 1){ finish(); } return super .onOptionsItemSelected(item); } }
second.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" > <Button android:id="@ id/second" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>
Three.java
package tk.myactivity06; import tk.myactivity06.Second.SecondButtonListener; import android.app.Activity; import android.content.Intent; import android.net.Uri; 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 Three extends Activity{ private Button myButton=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.three); myButton=(Button)findViewById(R.id.three); myButton.setText(R.string.three); myButton.setOnClickListener(new ThreeButtonListener()); } class ThreeButtonListener implements OnClickListener{ @Override public void onClick(View v){ Intent intent=new Intent(); intent.setClass(Three.this,First.class ); Three.this.startActivity(intent); finish(); } } //添加菜单 @Override public boolean onCreateOptionsMenu(Menu menu) { menu.add(0, 1, 1, R.string.exit ); menu.add(0, 2, 2, R.string.about); getMenuInflater().inflate(R.menu.first, menu); return true; } //菜单项处理 @Override public boolean onOptionsItemSelected(MenuItem item) { if(item.getItemId() == 1){ finish(); } return super .onOptionsItemSelected(item); } }
three.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" > <Button android:id="@ id/three" android:layout_width="fill_parent" android:layout_height="wrap_content" ></Button> </LinearLayout>
About.java
package tk.myactivity06; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class About extends Activity{ private Button myButton=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.about); myButton=(Button)findViewById(R.id.about); myButton.setText(R.string.about); myButton.setOnClickListener(new AboutButtonListener()); } class AboutButtonListener implements OnClickListener{ @Override public void onClick(View v){ finish(); } } }
about.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" > <Button android:id="@ id/about" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>
manifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="tk.myactivity06" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="15" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".First" android:label="@string/title_activity_first" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".Second" android:label="@string/second" > </activity> <activity android:name=".About" android:label="@string/about" android:theme="@android:style/Theme.Dialog" > </activity> <activity android:name=".Three" android:label="@string/three" > </activity> </application> </manifest>