Android 开发之为ActionBar 添加Actionbar Button

前几天做App 的时候，做的比较仓促，就没有添加返回按钮，还有就是MainActivity 的Theme 怎么传递到其他Activity 中，今天无意中看到官方的Train，所以就记下来啦，顺便吧ActionBar，Menu 也复习复习；

添加Action Buttons

首先我们要创建menu 文件，我们可以为顶部添加Menu，showAsAction 是显示的类型，ifRoom 会自动匹配是否有实体键，always 是一直隐藏，但是使用Support Libraryandroid:showAsAction="ifRoom" 会提示错误，所以在menu 中添加xmlns:app="http://schemas.android.com/apk/res-auto" 属性，改为app:showAsAction="ifRoom" 就没有错误；

res/menu/main_activity_actions.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >    <!-- Search, should appear as action button -->    <item android:id="@+id/action_search"          android:icon="@drawable/ic_action_search"          android:title="@string/action_search"          android:showAsAction="ifRoom" />    <!-- Settings, should always be in the overflow -->    <item android:id="@+id/action_settings"          android:title="@string/action_settings"          android:showAsAction="never" /></menu>

添加ActionBar

@Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.menu_main, menu);        return true;    }

为Action Button 添加响应事件

@Overridepublic boolean onOptionsItemSelected(MenuItem item) {    int id = item.getItemId();    //当点击不同的menu item 是执行不同的操作    switch (id) {        case R.id.action_search:            openSearch();            break;        case R.id.action_settings:            openSettings();            break;        default:            break;    }    return super.onOptionsItemSelected(item);}

为ActionBar 顶部添加返回按钮

首先要在AndroidManifest 文件中配置

<application ... >    ...    <!-- The main/home activity (it has no parent activity) -->    <activity        android:name="com.example.myfirstapp.MainActivity" ...>        ...    </activity>    <!-- A child of the main activity -->    <activity        android:name="com.example.myfirstapp.DisplayMessageActivity"        android:label="@string/title_activity_display_message"        android:parentActivityName="com.example.myfirstapp.MainActivity" >        <!-- Parent activity meta-data to support 4.0 and lower -->        <meta-data            android:name="android.support.PARENT_ACTIVITY"            android:value="com.example.myfirstapp.MainActivity" />    </activity></application>

然后在onCrate 中设置

@Overridepublic void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_displaymessage);    // 3.0+     getSupportActionBar().setDisplayHomeAsUpEnabled(true);    // If your minSdkVersion is 11 or higher, instead use:    // getActionBar().setDisplayHomeAsUpEnabled(true);}

最后的效果图

为下一个Activity 传递MainActivity Theme

需要注意的是，setTheme 方法在setContentView 之前；其实就是利用Intent 将Theme 传递到下一个Activity；

public class MainActivity extends ActionBarActivity {    public static int MAIN_THEME_STYLE_ID = R.style.Theme_AppCompat_Light;    public static String MAIN_THEME_STYLE = "Theme_AppCompat_Light";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setTheme(R.style.Theme_AppCompat_Light);        setContentView(R.layout.activity_main);    }    public void onToBackActivity(View view) {        Intent intent = new Intent(this, BackActivity.class);        intent.putExtra(MAIN_THEME_STYLE, MAIN_THEME_STYLE_ID);        startActivity(intent);    }}

在下一个Activity 获取Theme

public class BackActivity extends ActionBarActivity {    int style_id;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        getMainIntent();        setTheme(style_id);        setContentView(R.layout.activity_back);        getSupportActionBar().setDisplayShowCustomEnabled(true);    }    void getMainIntent() {        Intent intent = getIntent();        style_id = intent.getIntExtra(MainActivity.MAIN_THEME_STYLE, 0);    }}

原文地址

• Android 学习为ActionBar 添加返回按钮 · Issue #29 · Tikitoo/blog