package com.example;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch(item.getItemId()){
case R.id.start:
case R.id.stop:
invalidateOptionsMenu();
break;
case R.id.exit:
finish();
break;
default:
break;
}
Toast.makeText(MainActivity.this, item.getTitle()+"被单击了", 1000).show();
return true;
}
public boolean onPrepareOptionsMenu(Menu menu){
super.onPrepareOptionsMenu(menu);
MenuItem start=menu.findItem(R.id.start);
MenuItem stop=menu.findItem(R.id.stop);
boolean flag = false;
start.setEnabled(flag);
stop.setEnabled(!flag);
flag=!flag;
return true;
}
}
/* AUTO-GENERATED FILE. DO NOT MODIFY.
*
- This class was automatically generated by the
- aapt tool from the resource data it found. It
- should not be modified by hand. */
package com.example;
public final class R {
public static final class attr {
}
public static final class dimen {
/** Default screen margins, per the Android Design guidelines.
Example customization of dimensions originally defined in res/values/dimens.xml
(such as screen margins) for screens with more than 820dp of available width. This
would include 7" and 10" devices in landscape (~960dp and ~1280dp respectively).
*/
public static final int activity_horizontal_margin=0x7f040000;
public static final int activity_vertical_margin=0x7f040001;
}
public static final class drawable {
public static final int ic_launcher=0x7f020000;
}
public static final class id {
public static final int action_settings=0x7f080000;
}
public static final class layout {
public static final int activity_main=0x7f030000;
}
public static final class menu {
public static final int main=0x7f070000;
}
public static final class string {
public static final int action_settings=0x7f050002;
public static final int app_name=0x7f050000;
public static final int hello_world=0x7f050001;
}
public static final class style {
/**
Base application theme, dependent on API level. This theme is replaced
by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
Theme customizations available in newer API levels can go in
res/values-vXX/styles.xml, while customizations related to
backward-compatibility can go here.
Base application theme for API 11+. This theme completely replaces
AppBaseTheme from res/values/styles.xml on API 11+ devices.
API 11 theme customizations can go here.
Base application theme for API 14+. This theme completely replaces
AppBaseTheme from BOTH res/values/styles.xml and
res/values-v11/styles.xml on API 14+ devices.
API 14 theme customizations can go here.
/
public static final int AppBaseTheme=0x7f060000;
/* Application theme.
All customizations that are NOT specific to a particular API-level can go here.
*/
public static final int AppTheme=0x7f060001;
}
}
R文件里边的id不产生start ，stop，exit的属性值
