Android UI开发第三十五篇——AppCompat实现Action Bar

每一位Android开发者对Action Bar这种设计都不陌生了，毕竟它已经发布了至少两年了。Android团队发布Action Bar设计规范时同时放出了ActionBar的Api来支持这种设计。如果对ActionBar不太熟悉的可以参考《

Android UI开发第二十四篇——Action Bar》。ActionBar的API被添加在Android3.0（API 级别 11）中，低版本的还是用不了，根本不能适配支持Android 2.X系列的应用。很幸运有第三方开源的actionbarsherlock支持使得Android 2.1以上的Android应用使用actionbarsherlock定义的Action Bar。这里我们不介绍actionbarsherlock怎么使用，我们介绍一种更新的官方支持的AppCompat 使得Android2.1以上的版本可以实现Action Bar。

Google I/O 2013中AppCompat实现的Action Bar效果

AppCompat在最新的API 18的Android Support Library中。使用AppCompat需要以库的形式引入到应用中，AppCompat在<sdk>/extras/android/support/v7/appcompat/ 的位置，需要自行下载，或者升级SDK。

如果应用是使用actionbarsherlock实现的Action Bar，也不必刻意的改成AppCompat。因为actionbarsherlock是一个很稳定的经过很多开发者验证的开发库。

[html] view plaincopyprint?

1. ActionBarSherlock is a solid and well-tested library which has served developers very well for a long time.
2. If you are already using it and do not currently require any of the above then there is no need to migrate.

    ActionBarSherlock is a solid and well-tested library which has served developers very well for a long time.     If you are already using it and do not currently require any of the above then there is no need to migrate.   

1）导入AppCompat库

使用AppCompat第一步需要导入AppCompat库，这一步就不做详细介绍了。

2）修改android:theme

每个使用Action Bar的Activity都应该添加Android:theme

[html] view plaincopyprint?

1. <activity
2. ...
3. android:theme="@style/Theme.AppCompat"/>

<activity        ...        android:theme="@style/Theme.AppCompat" />

或者修改application

[html] view plaincopyprint?

1. <application
2. android:label="@string/app_name"
3. android:icon="@drawable/ic_launcher"
4. android:theme="@style/Theme.AppCompat"
5. android:allowBackup="true">

 <application        android:label="@string/app_name"        android:icon="@drawable/ic_launcher"        android:theme="@style/Theme.AppCompat"         android:allowBackup="true">

3）Activity要继承自ActionBarActivity

实现Action Bar的视图需要继承ActionBarActivity。

4）修改menu的命名空间

[html] view plaincopyprint?

1. <menu xmlns:android="http://schemas.android.com/apk/res/android"
2. xmlns:holo="http://schemas.android.com/apk/res-auto">
4. <item
5. android:id="@+id/action_websearch"
6. android:icon="@drawable/action_search"
7. android:title="@string/action_websearch"
8. holo:showAsAction="never"/>
9. </menu>

<menu xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:holo="http://schemas.android.com/apk/res-auto" >    <item        android:id="@+id/action_websearch"        android:icon="@drawable/action_search"        android:title="@string/action_websearch"        holo:showAsAction="never"/></menu>

要特别注意的是，通过XML文件来实现Action Item，一定要自定义命名空间，而且该命名空间的后缀一定要和item中showAsAction的前缀一致，本例中为“holo”

显示Menu需要重写onCreateOptionsMenu方法：

[java] view plaincopyprint?

1. @Override
2. public boolean onCreateOptionsMenu(Menu menu) {
3. MenuInflater inflater = getMenuInflater();
4. inflater.inflate(R.menu.main, menu);
5. return super.onCreateOptionsMenu(menu);
6. }

 @Override    public boolean onCreateOptionsMenu(Menu menu) {        MenuInflater inflater = getMenuInflater();        inflater.inflate(R.menu.main, menu);        return super.onCreateOptionsMenu(menu);    }

对Menu的item事件处理需要重写onOptionsItemSelected方法。

[java] view plaincopyprint?

1. @Override
2. public boolean onOptionsItemSelected(MenuItem item) {
3. // The action bar home/up action should open or close the drawer.
4. // ActionBarDrawerToggle will take care of this.
5. if (mDrawerToggle.onOptionsItemSelected(item)) {
6. return true;
7. }
8. // Handle action buttons
9. switch(item.getItemId()) {
10. case R.id.action_websearch:
11. // create intent to perform web search for this planet
12. Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
13. intent.putExtra(SearchManager.QUERY, getSupportActionBar().getTitle());
14. // catch event that there's no activity to handle intent
15. if (intent.resolveActivity(getPackageManager()) !=null) {
16. startActivity(intent);
17. } else {
18. Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
19. }
20. return true;
21. default:
22. return super.onOptionsItemSelected(item);
23. }
24. }

@Override    public boolean onOptionsItemSelected(MenuItem item) {         // The action bar home/up action should open or close the drawer.         // ActionBarDrawerToggle will take care of this.        if (mDrawerToggle.onOptionsItemSelected(item)) {            return true;        }        // Handle action buttons        switch(item.getItemId()) {        case R.id.action_websearch:            // create intent to perform web search for this planet            Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);            intent.putExtra(SearchManager.QUERY, getSupportActionBar().getTitle());            // catch event that there's no activity to handle intent            if (intent.resolveActivity(getPackageManager()) != null) {                startActivity(intent);            } else {                Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();            }            return true;        default:            return super.onOptionsItemSelected(item);        }    }

上面就是简单的通过Appcompat实现Action Bar，想自定义各种属性请参考官方文档。

demo下载：demo

/**

* @author 张兴业

* http://blog.csdn.net/xyz_lmn

* iOS入门群：83702688

* android开发进阶群：241395671

* 我的新浪微博：@张兴业TBOW

*/

参考：

http://antonioleiva.com/actionbarcompat-how-to-use/

http://antonioleiva.com/actionbarcompat-action-views/

http://android-developers.blogspot.com/2013/08/actionbarcompat-and-io-2013-app-source.html

每一位Android开发者对Action Bar这种设计都不陌生了，毕竟它已经发布了至少两年了。Android团队发布Action Bar设计规范时同时放出了ActionBar的Api来支持这种设计。如果对ActionBar不太熟悉的可以参考《

Android UI开发第二十四篇——Action Bar》。ActionBar的API被添加在Android3.0（API 级别 11）中，低版本的还是用不了，根本不能适配支持Android 2.X系列的应用。很幸运有第三方开源的actionbarsherlock支持使得Android 2.1以上的Android应用使用actionbarsherlock定义的Action Bar。这里我们不介绍actionbarsherlock怎么使用，我们介绍一种更新的官方支持的AppCompat 使得Android2.1以上的版本可以实现Action Bar。

Google I/O 2013中AppCompat实现的Action Bar效果

AppCompat在最新的API 18的Android Support Library中。使用AppCompat需要以库的形式引入到应用中，AppCompat在<sdk>/extras/android/support/v7/appcompat/ 的位置，需要自行下载，或者升级SDK。

如果应用是使用actionbarsherlock实现的Action Bar，也不必刻意的改成AppCompat。因为actionbarsherlock是一个很稳定的经过很多开发者验证的开发库。

[html] view plaincopyprint?

1. ActionBarSherlock is a solid and well-tested library which has served developers very well for a long time.
2. If you are already using it and do not currently require any of the above then there is no need to migrate.

    ActionBarSherlock is a solid and well-tested library which has served developers very well for a long time.     If you are already using it and do not currently require any of the above then there is no need to migrate.   

1）导入AppCompat库

使用AppCompat第一步需要导入AppCompat库，这一步就不做详细介绍了。

2）修改android:theme

每个使用Action Bar的Activity都应该添加Android:theme

[html] view plaincopyprint?

1. <activity
2. ...
3. android:theme="@style/Theme.AppCompat"/>

<activity        ...        android:theme="@style/Theme.AppCompat" />

或者修改application

[html] view plaincopyprint?

1. <application
2. android:label="@string/app_name"
3. android:icon="@drawable/ic_launcher"
4. android:theme="@style/Theme.AppCompat"
5. android:allowBackup="true">

 <application        android:label="@string/app_name"        android:icon="@drawable/ic_launcher"        android:theme="@style/Theme.AppCompat"         android:allowBackup="true">

3）Activity要继承自ActionBarActivity

实现Action Bar的视图需要继承ActionBarActivity。

4）修改menu的命名空间

[html] view plaincopyprint?

1. <menu xmlns:android="http://schemas.android.com/apk/res/android"
2. xmlns:holo="http://schemas.android.com/apk/res-auto">
4. <item
5. android:id="@+id/action_websearch"
6. android:icon="@drawable/action_search"
7. android:title="@string/action_websearch"
8. holo:showAsAction="never"/>
9. </menu>

<menu xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:holo="http://schemas.android.com/apk/res-auto" >    <item        android:id="@+id/action_websearch"        android:icon="@drawable/action_search"        android:title="@string/action_websearch"        holo:showAsAction="never"/></menu>

要特别注意的是，通过XML文件来实现Action Item，一定要自定义命名空间，而且该命名空间的后缀一定要和item中showAsAction的前缀一致，本例中为“holo”

显示Menu需要重写onCreateOptionsMenu方法：

[java] view plaincopyprint?

1. @Override
2. public boolean onCreateOptionsMenu(Menu menu) {
3. MenuInflater inflater = getMenuInflater();
4. inflater.inflate(R.menu.main, menu);
5. return super.onCreateOptionsMenu(menu);
6. }

 @Override    public boolean onCreateOptionsMenu(Menu menu) {        MenuInflater inflater = getMenuInflater();        inflater.inflate(R.menu.main, menu);        return super.onCreateOptionsMenu(menu);    }

对Menu的item事件处理需要重写onOptionsItemSelected方法。

[java] view plaincopyprint?

1. @Override
2. public boolean onOptionsItemSelected(MenuItem item) {
3. // The action bar home/up action should open or close the drawer.
4. // ActionBarDrawerToggle will take care of this.
5. if (mDrawerToggle.onOptionsItemSelected(item)) {
6. return true;
7. }
8. // Handle action buttons
9. switch(item.getItemId()) {
10. case R.id.action_websearch:
11. // create intent to perform web search for this planet
12. Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
13. intent.putExtra(SearchManager.QUERY, getSupportActionBar().getTitle());
14. // catch event that there's no activity to handle intent
15. if (intent.resolveActivity(getPackageManager()) !=null) {
16. startActivity(intent);
17. } else {
18. Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
19. }
20. return true;
21. default:
22. return super.onOptionsItemSelected(item);
23. }
24. }

@Override    public boolean onOptionsItemSelected(MenuItem item) {         // The action bar home/up action should open or close the drawer.         // ActionBarDrawerToggle will take care of this.        if (mDrawerToggle.onOptionsItemSelected(item)) {            return true;        }        // Handle action buttons        switch(item.getItemId()) {        case R.id.action_websearch:            // create intent to perform web search for this planet            Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);            intent.putExtra(SearchManager.QUERY, getSupportActionBar().getTitle());            // catch event that there's no activity to handle intent            if (intent.resolveActivity(getPackageManager()) != null) {                startActivity(intent);            } else {                Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();            }            return true;        default:            return super.onOptionsItemSelected(item);        }    }

上面就是简单的通过Appcompat实现Action Bar，想自定义各种属性请参考官方文档。

demo下载：demo

/**

* @author 张兴业

* http://blog.csdn.net/xyz_lmn

* iOS入门群：83702688

* android开发进阶群：241395671

* 我的新浪微博：@张兴业TBOW

*/

参考：

http://antonioleiva.com/actionbarcompat-how-to-use/

http://antonioleiva.com/actionbarcompat-action-views/

http://android-developers.blogspot.com/2013/08/actionbarcompat-and-io-2013-app-source.html