【发布时间】:2015-07-19 22:24:17
【问题描述】:
我已经为我的问题准备了a simple test project at GitHub。
它基于the well-known Navigation Drawer Example by Google - 由右侧抽屉扩展,在 ListView 中具有与音乐相关的操作:
动作都定义在res/values/strings.xml中:
<string-array name="music_actions">
<item>Play</item>
<item>Pause</item>
<item>Stop</item>
<item>Shuffle</item>
</string-array>
<integer-array name="music_icons">
<item>@drawable/ic_play_arrow_black_24dp</item>
<item>@drawable/ic_pause_black_24dp</item>
<item>@drawable/ic_stop_black_24dp</item>
<item>@drawable/ic_shuffle_black_24dp</item>
</integer-array>
这是从资源中读取它们的代码(效果很好):
public class MainActivity extends AppCompatActivity {
private String[] mActions;
private int[] mIcons;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mActions = getResources().getStringArray(R.array.music_actions);
TypedArray ta = getResources().obtainTypedArray(R.array.music_icons);
mIcons = new int[ta.length()];
for (int i = 0; i < mIcons.length; i++)
mIcons[i] = ta.getResourceId(i, R.drawable.ic_menu_black_24dp);
ta.recycle();
我的问题是:
从ListView的监听器中的onItemClick方法——如何调用Fragment中的对应方法?
我只看到了丑陋的方法,比如这里有一个硬编码的switch 声明:
mRightDrawer.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mActions) {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView view = (TextView) super.getView(position, convertView, parent);
view.setCompoundDrawablesWithIntrinsicBounds(mIcons[position], 0, 0, 0);
return view;
}
});
mRightDrawer.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (mActiveFragment instanceof GameFragment) {
GameFragment fragment = (GameFragment) mActiveFragment;
switch (position) {
case 0:
fragment.playMusic(); // and then this calls myView.playMusic();
break;
case 1:
fragment.pauseMusic(); // calls myView.pauseMusic();
break;
}
}
mDrawerLayout.closeDrawer(mRightDrawer);
}
});
这很难看,因为我必须跟踪我当前活动的 Fragment,然后使用包装器方法最终调用我的自定义 View 上的方法。
如何改善这种情况,我是否应该在自定义视图中使用BroadcastReceiver?
我希望,我可以在我的资源中定义 icon + title + action,然后直接使用它们。
更新:
目前我正在使用BroadcastReceiver,但想知道这是否是一个合适的解决方案(或者可能过于繁重?)。
在我的片段中我调用:
@Override
public void onResume() {
super.onResume();
myView.register();
}
@Override
public void onPause() {
super.onPause();
myView.unregister();
}
在我的自定义视图中,我有:
public class MyView extends View {
public final static String ACTION_PLAY = "de.afarber.myapp.play";
public final static String ACTION_PAUSE = "de.afarber.myapp.pause";
public final static String ACTION_STOP = "de.afarber.myapp.stop";
public final static String ACTION_SHUFFLE = "de.afarber.myapp.shuffle";
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_PLAY.equals(action))
playMusic();
else if (ACTION_PAUSE.equals(action))
pauseMusic();
else if (ACTION_STOP.equals(action))
stopMusic();
else if (ACTION_SHUFFLE.equals(action))
shuffleMusic();
}
};
public void register() {
IntentFilter filter = new IntentFilter();
filter.addAction(ACTION_PLAY);
filter.addAction(ACTION_PAUSE);
filter.addAction(ACTION_STOP);
filter.addAction(ACTION_SHUFFLE);
getContext().registerReceiver(mMessageReceiver, filter);
}
我希望为 Fragments 提供某种“上下文菜单” - 定义 title + icon + action - 然后可以由右侧 Drawer 中的 actions-ListView 使用...
public void unregister() {
getContext().unregisterReceiver(mMessageReceiver);
}
【问题讨论】:
标签: android android-fragments android-listview android-resources android-broadcast