首先，感谢大家这个伟大的社区。
我正在尝试按照支持演示示例代码实现一个选项卡式片段接口。
最高层，我正在尝试实现两个选项卡，将单个片段与每个选项卡相关联，并在选择每个选项卡时相应地显示片段。
目前，我有两个问题（但我确定它们是相关的...）
1) 每个选项卡的片段彼此重叠。 这可能与不适当的片段附加/分离有关。
2) 第三个神秘的碎片在某个地方被创建并重叠其他碎片。
在模拟器上（以及在物理设备上），您可以看到选择任一选项卡时有两个重叠的片段
当选择选项卡1时， 片段1和未知片段重叠。
当选择选项卡2时， 片段1和片段2重叠。
链接到截图（没有足够的声望上传照片...）
（选项卡1重叠）http://s8.postimg.org/kv81yz745/tab1_overlapping.png
（选项卡2重叠）http://s8.postimg.org/3tf7wvs91/tab2_overlapping.png
在这里，我已经为演示/清晰度目的分离了每个片段的文本。
这些截图的链接在我的评论/回复中（没有足够的声望上传超过2个链接...）
活动布局（fragment_tabs.xml）
<TabHost
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TabWidget
android:id="@android:id/tabs"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="0"/>
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="0"/>
<FrameLayout
android:id="@+id/realtabcontent"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
</LinearLayout>
</TabHost>
源代码
public class TabbedInfoHome extends SherlockFragmentActivity {
TabHost mTabHost;
TabManager mTabManager;
static String tag1name = "simple1";
static String tag2name = "simple2";
static String tab1string = "You are looking at fragment 1";
static String tab2string = "You are looking at fragment 2";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_tabs);
if (savedInstanceState == null) {
// Do first time initialization -- add initial fragment.
Fragment frag1 = CountingFragment.newInstance(tab1string);
Fragment frag2 = CountingFragment.newInstance(tab2string);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.realtabcontent, frag1, tag1name);
ft.add(R.id.realtabcontent, frag2, tag2name);
ft.commit();
}
else {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
}
mTabHost = (TabHost)findViewById(android.R.id.tabhost);
mTabHost.setup();
mTabManager = new TabManager(this, mTabHost, R.id.realtabcontent);
mTabManager.addTab(mTabHost.newTabSpec(tag1name)
.setIndicator(tag1name),
TabbedInfoHome.CountingFragment.class,
null);
mTabManager.addTab(mTabHost.newTabSpec(tag2name)
.setIndicator(tag2name),
TabbedInfoHome.CountingFragment.class,
null);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("tab", mTabHost.getCurrentTabTag());
}
public static class CountingFragment extends SherlockFragment {
String displayString;
String FRAGMENT_TAG = this.getClass().getSimpleName();
/**
* Create a new instance of CountingFragment, providing "num"
* as an argument.
*/
static CountingFragment newInstance(String toDisplay) {
CountingFragment f = new CountingFragment();
Bundle args = new Bundle();
args.putString("string", toDisplay);
f.setArguments(args);
return f;
}
/* When creating, retrieve this instance's number from its arguments. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
displayString = getArguments() != null ? getArguments().getString("string") : "no string was passed in!";
}
/* The Fragment's UI is just a simple text view showing its
* instance number. */
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.hello_world, container, false);
View tv = v.findViewById(R.id.text);
boolean separateStrings = false;
/* the overlapping is hard to decipher, so
* lets illustrate how both fragments are appearing */
if(separateStrings) {
String temp;
/* b/c I only created TWO instances of the CountingFragments object,
* there should only be TWO "displayStrings" to consider...
*/
if( (displayString.compareTo(tab1string) == 0) ) {
/* user clicked tab 1 */
temp = "\n\n\n\n" + displayString;
}
else if( (displayString.compareTo(tab2string) == 0) ) {
/* user clicked tab2 */
temp = "\n\n\n\n\n\n\n" + displayString;
}
else {
/* unknown CountingFragment instance */
temp = "What am I doing here..??? ";
}
((TextView)tv).setText(temp);
}
else {
/* normal case of the fragment being shown; (but they overlap!) */
((TextView)tv).setText(displayString);
}
return v;
}
}
/**
* This is a helper class that implements a generic mechanism for
* associating fragments with the tabs in a tab host. It relies on a
* trick. Normally a tab host has a simple API for supplying a View or
* Intent that each tab will show. This is not sufficient for switching
* between fragments. So instead we make the content part of the tab host
* 0dp high (it is not shown) and the TabManager supplies its own dummy
* view to show as the tab content. It listens to changes in tabs, and takes
* care of switch to the correct fragment shown in a separate content area
* whenever the selected tab changes.
*/
public static class TabManager implements TabHost.OnTabChangeListener {
private final FragmentActivity mActivity;
private final TabHost mTabHost;
private final int mContainerId;
private final HashMap<String, TabInfo> mTabs = new HashMap<String, TabInfo>();
TabInfo mLastTab;
static final class TabInfo {
private final String tag;
private final Class<?> clss;
private final Bundle args;
private Fragment fragment;
TabInfo(String _tag, Class<?> _class, Bundle _args) {
tag = _tag;
clss = _class;
args = _args;
}
}
static class DummyTabFactory implements TabHost.TabContentFactory {
private final Context mContext;
public DummyTabFactory(Context context) {
mContext = context;
}
@Override
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
public TabManager(FragmentActivity activity, TabHost tabHost, int containerId) {
mActivity = activity;
mTabHost = tabHost;
mContainerId = containerId;
mTabHost.setOnTabChangedListener(this);
}
public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
tabSpec.setContent(new DummyTabFactory(mActivity));
String tag = tabSpec.getTag();
TabInfo info = new TabInfo(tag, clss, args);
// Check to see if we already have a fragment for this tab, probably
// from a previously saved state. If so, deactivate it, because our
// initial state is that a tab isn't shown.
info.fragment = mActivity.getSupportFragmentManager().findFragmentByTag(tag);
if (info.fragment != null ) { // && !info.fragment.isDetached()) {
Log.d("addingTab", "we already have a fragment for this tab. tabInfo.fragment.id: " + info.fragment.getId());
FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
ft.detach(info.fragment);
ft.commit();
mActivity.getSupportFragmentManager().executePendingTransactions();
}
// associate the tabSpec tag with a particular TabInfo object
mTabs.put(tag, info);
mTabHost.addTab(tabSpec);
}
@Override
public void onTabChanged(String tabId) {
TabInfo newTab = mTabs.get(tabId);
if (mLastTab != newTab) {
FragmentTransaction ft = mActivity.getSupportFragmentManager().beginTransaction();
if (mLastTab != null) {
if (mLastTab.fragment != null) {
ft.detach(mLastTab.fragment);
}
}
if (newTab != null) {
if (newTab.fragment == null) {
newTab.fragment = Fragment.instantiate(mActivity,
newTab.clss.getName(), newTab.args);
ft.add(mContainerId, newTab.fragment, newTab.tag);
} else {
ft.attach(newTab.fragment);
}
}
mLastTab = newTab;
ft.commit();
mActivity.getSupportFragmentManager().executePendingTransactions();
}
}
}