Android Action Bar 示例代碼
今天一起來看下Android Action Bar的示例代碼,我們通過活動欄做一個簡單選項菜單。下面這個例子將演示ActionBar.NAVIGATION_MODE_STANDARD、 ActionBar.NAVIGATION_MODE_TABS和 : ActionBar.NAVIGATION_MODE_STANDARD等模式的效果。最后仍然要提示大家Action Bar是Android 3.0 honeycomb才開始有的特性,老版本的SDK和固件無法使用。
public class ActionBarDisplayOptions extends Activity implements View.OnClickListener, ActionBar.TabListener {private View mCustomView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.action_bar_display_options);
findViewById(R.id.toggle_home_as_up).setOnClickListener(this);
findViewById(R.id.toggle_show_home).setOnClickListener(this);
findViewById(R.id.toggle_use_logo).setOnClickListener(this);
findViewById(R.id.toggle_show_title).setOnClickListener(this);
findViewById(R.id.toggle_show_custom).setOnClickListener(this);
findViewById(R.id.toggle_navigation).setOnClickListener(this);
findViewById(R.id.cycle_custom_gravity).setOnClickListener(this);
mCustomView = getLayoutInflater().inflate(R.layout.action_bar_display_options_custom, null);
final ActionBar bar = getActionBar();
bar.setCustomView(mCustomView,
new ActionBar.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
bar.addTab(bar.newTab().setText("Tab 1").setTabListener(this));
bar.addTab(bar.newTab().setText("Tab 2").setTabListener(this));
bar.addTab(bar.newTab().setText("Tab 3").setTabListener(this));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.display_options_actions, menu);
return true;
}
public void onClick(View v) {
final ActionBar bar = getActionBar();
int flags = 0;
switch (v.getId()) {
case R.id.toggle_home_as_up:
flags = ActionBar.DISPLAY_HOME_AS_UP;
break;
case R.id.toggle_show_home:
flags = ActionBar.DISPLAY_SHOW_HOME;
break;
case R.id.toggle_use_logo:
flags = ActionBar.DISPLAY_USE_LOGO;
break;
case R.id.toggle_show_title:
flags = ActionBar.DISPLAY_SHOW_TITLE;
break;
case R.id.toggle_show_custom:
flags = ActionBar.DISPLAY_SHOW_CUSTOM;
break;
case R.id.toggle_navigation:
bar.setNavigationMode(
bar.getNavigationMode() == ActionBar.NAVIGATION_MODE_STANDARD
? ActionBar.NAVIGATION_MODE_TABS
: ActionBar.NAVIGATION_MODE_STANDARD);
return;
case R.id.cycle_custom_gravity:
ActionBar.LayoutParams lp = (ActionBar.LayoutParams) mCustomView.getLayoutParams();
int newGravity = 0;
switch (lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK) {
case Gravity.LEFT:
newGravity = Gravity.CENTER_HORIZONTAL;
break;
case Gravity.CENTER_HORIZONTAL:
newGravity = Gravity.RIGHT;
break;
case Gravity.RIGHT:
newGravity = Gravity.LEFT;
break;
}
lp.gravity = lp.gravity & ~Gravity.HORIZONTAL_GRAVITY_MASK | newGravity;
bar.setCustomView(mCustomView, lp);
return;
}
int change = bar.getDisplayOptions() ^ flags;
bar.setDisplayOptions(change, flags);
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}</pre>
接下來是文中涉及的3個xml布局文件:
相關的XML布局action_bar_display_options.xml代碼為
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Button android:id="@+id/toggle_home_as_up" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/toggle_home_as_up" ;/>
<Button android:id="@+id/toggle_show_home" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/toggle_show_home" ;/>
<Button android:id="@+id/toggle_use_logo" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/toggle_use_logo" ;/>
<Button android:id="@+id/toggle_show_title" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/toggle_show_title" ;/>
<Button android:id="@+id/toggle_show_custom" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/toggle_show_custom" ;/>
<Button android:id="@+id/toggle_navigation" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/toggle_navigation" ;/>
<Button android:id="@+id/cycle_custom_gravity" ; android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/cycle_custom_gravity" ;/>
</LinearLayout></pre>
相關的自定義布局文件action_bar_display_options_custom.xml代碼為
<?xml version="1.0" encoding="utf-8"?> <Button xmlns:android="http://schemas.android.com/apk/res/android"android:text="@string/display_options_custom_button" ;/></pre>
相關的menu布局xml文件display_options_actions.xml代碼為
<?xml version="1.0" encoding="utf-8"?><menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@+id/simple_item" ; android:title="@string/display_options_menu_item" ;/>
</menu></pre>
上面的string后的元素大家可以根據自己的情況進行替換。
ActionBar相關的示例代碼第二部分分為兩種,作為Android 3.0的重要特性我們直接看代碼:
一、使用菜單資源構造
public class ActionBarMechanics extends Activity {@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getWindow().requestFeature(Window.FEATURE_ACTION_BAR); }
@Override public boolean onCreateOptionsMenu(Menu menu) { menu.add("Normal item"); MenuItem actionItem = menu.add("Action Button"); actionItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM); actionItem.setIcon(android.R.drawable.ic_menu_share); return true; }
@Override public boolean onOptionsItemSelected(MenuItem item) { Toast.makeText(this, "Selected Item: " + item.getTitle(), Toast.LENGTH_SHORT).show(); return true; } }</pre>
二、作為Tab切換Fragment
public class ActionBarTabs extends Activity {@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.action_bar_tabs); }
public void onAddTab(View v) { final ActionBar bar = getActionBar(); final int tabCount = bar.getTabCount(); final String text = "Tab " + tabCount; bar.addTab(bar.newTab() .setText(text) .setTabListener(new TabListener(new TabContentFragment(text)))); }
public void onRemoveTab(View v) { final ActionBar bar = getActionBar(); bar.removeTabAt(bar.getTabCount() - 1); }
public void onToggleTabs(View v) { final ActionBar bar = getActionBar(); if (bar.getNavigationMode() == ActionBar.NAVIGATION_MODE_TABS) { bar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); bar.setDisplayOptions(ActionBar.DISPLAY_SHOW_TITLE, ActionBar.DISPLAY_SHOW_TITLE); } else { bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE); } }
public void onRemoveAllTabs(View v) { getActionBar().removeAllTabs(); }
private class TabListener implements ActionBar.TabListener { private TabContentFragment mFragment;
public TabListener(TabContentFragment fragment) { mFragment = fragment; }
public void onTabSelected(Tab tab, FragmentTransaction ft) { ft.add(R.id.fragment_content, mFragment, mFragment.getText()); }
public void onTabUnselected(Tab tab, FragmentTransaction ft) { ft.remove(mFragment); }
public void onTabReselected(Tab tab, FragmentTransaction ft) { Toast.makeText(ActionBarTabs.this, "Reselected!", Toast.LENGTH_SHORT).show(); }
}
private class TabContentFragment extends Fragment {
private String mText;
public TabContentFragment(String text) { mText = text; }
public String getText() { return mText; }
@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View fragView = inflater.inflate(R.layout.action_bar_tab_content, container, false); TextView text = (TextView) fragView.findViewById(R.id.text); text.setText(mText); return fragView; } } }</pre>
涉及的布局文件action_bar_tabs.xml代碼為
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <FrameLayout android:id="@+id/fragment_content"
; android:layout_width="match_parent" android:layout_height="0dip" android:layout_weight="1" /> <LinearLayout android:layout_width="match_parent"
android:layout_height="0dip" android:layout_weight="1" android:orientation="vertical"> <Button android:id="@+id/btn_add_tab"
; android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/btn_add_tab" ; android:onClick="onAddTab" /> <Button android:id="@+id/btn_remove_tab"
; android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/btn_remove_tab" ; android:onClick="onRemoveTab" /> <Button android:id="@+id/btn_toggle_tabs"
; android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/btn_toggle_tabs" ; android:onClick="onToggleTabs" /> <Button android:id="@+id/btn_remove_all_tabs"
; android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/btn_remove_all_tabs" ; android:onClick="onRemoveAllTabs" /> </LinearLayout>
</LinearLayout></pre>
涉及布局文件action_bar_tab_content.xml的代碼為
<?xml version="1.0" encoding="utf-8"?> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/text"; android:layout_width="wrap_content" android:layout_height="wrap_content" /></pre>