我有一个应用程序，我迫切需要从使用旧的 ActivityGroup 类转换为 Fragments。我不知道该怎么做。下面是我现在使用的代码示例。谁能提供一些关于我应该采取哪些步骤来开始将其切换为使用 Fragments / FragmentManager 的见解？
主.java
public class Main extends TabActivity implements OnTabChangeListener {
public static TextView txtViewHeading;
public static Button btnBack;
public static ImageButton btnShare;
public static Main mainActivity;
public static Boolean isVisible = false;
private GoogleCloudMessaging gcm;
private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mainActivity = this;
NotificationsManager.handleNotifications(this, NotificationSettings.SenderId, PushHandler.class);
registerWithNotificationHubs();
//reference headings text & button for access from child activities
txtViewHeading = (TextView) findViewById(R.id.txtViewHeading);
btnBack = (Button) findViewById(R.id.btnBack);
btnShare = (ImageButton) findViewById(R.id.btnShare);
// Update the font for the heading and back button
Typeface arialTypeface = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/arial.ttf");
Typeface myriadTypeface = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/myriad.ttf");
txtViewHeading.setTypeface(myriadTypeface);
btnBack.setTypeface(arialTypeface);
Resources res = getResources();
TabHost tabsNavigation = getTabHost();
// Set up the views for each tab - custom view used for Badge icon
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
// Set up my tabs...each one looks similar to this
View statusTabView = inflater.inflate(R.layout.tab, null);
ImageView statusTabIcon = (ImageView) statusTabView.findViewById(R.id.tabIcon);
statusTabIcon.setImageResource(R.drawable.tab_first);
TextView statusTabText = (TextView) statusTabView.findViewById(R.id.tabText);
statusTabText.setText("Status");
statusTabText.setTypeface(arialTypeface);
statusTabBadge = (TextView) statusTabView.findViewById(R.id.tabBadge);
statusTabBadge.setTypeface(arialTypeface);
tabsNavigation.addTab(tabsNavigation.newTabSpec(getResources().getString(R.string.main_tab_status))
.setIndicator(statusTabView)
.setContent(new Intent(this, StatusGroupActivity.class)
.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));
//Set default tab to Status
tabsNavigation.setCurrentTab(0);
tabsNavigation.setOnTabChangedListener(this);
}
/* Set txtViewHeading text to selected tab text */
@Override
public void onTabChanged(String tabId) {
// TODO Auto-generated method stub
txtViewHeading.setText(tabId);
}
/* Set code to execute when onDestroy method is called */
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
}
/* Set code to execute when onPause method is called */
@Override
protected void onPause() {
super.onPause();
isVisible = false;
}
/* Set code to execute when onResume method is called */
@Override
protected void onResume() {
super.onResume();
isVisible = true;
}
/* Set code to execute when onStop method is called */
@Override
protected void onStop() {
super.onStop();
isVisible = false;
}
/**
* Check the device to make sure it has the Google Play Services APK. If
* it doesn't, display a dialog that allows users to download the APK from
* the Google Play Store or enable it in the device's system settings.
*/
private boolean checkPlayServices() {
GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance();
int resultCode = apiAvailability.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS) {
if (apiAvailability.isUserResolvableError(resultCode)) {
apiAvailability.getErrorDialog(this, resultCode, PLAY_SERVICES_RESOLUTION_REQUEST)
.show();
} else {
ToastNotify("This device is not supported by Google Play Services.");
finish();
}
return false;
}
return true;
}
public void ToastNotify(final String notificationMessage) {
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(Main.this, notificationMessage, Toast.LENGTH_LONG).show();
}
});
}
public void registerWithNotificationHubs()
{
if (checkPlayServices()) {
// Start IntentService to register this application with GCM.
Intent intent = new Intent(this, RegistrationIntentService.class);
startService(intent);
}
}
}
TabGroupActivity.java
public class TabGroupActivity extends ActivityGroup
{
private ArrayList<String> mIdList;
Button btnBack;
ImageButton btnShare;
TextView txtViewHeading;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
btnBack = Main.btnBack;
btnShare = Main.btnShare;
txtViewHeading = Main.txtViewHeading;
btnBack.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onBackPressed();
}
});
if (mIdList == null) mIdList = new ArrayList<String>();
}
/**
* This is called when a child activity of this one calls its finish method.
* This implementation calls {@link LocalActivityManager#destroyActivity} on the child activity
* and starts the previous activity.
* If the last child activity just called finish(),this activity (the parent),
* calls finish to finish the entire group.
*/
@Override
public void finishFromChild(Activity child)
{
try
{
btnShare.setVisibility(View.GONE);
LocalActivityManager manager = getLocalActivityManager();
int index = mIdList.size()-1;
if (index < 1)
{
finish();
return;
}
manager.destroyActivity(mIdList.get(index), true);
mIdList.remove(index);
index--;
String lastId = mIdList.get(index);
Intent lastIntent = manager.getActivity(lastId).getIntent();
Window newWindow = manager.startActivity(lastId, lastIntent);
setContentView(newWindow.getDecorView());
//Set Heading text to current Id
txtViewHeading.setText(getActivityHeading(lastId));
//Set Back button text to previous Id if applicable
btnBack.setVisibility(View.VISIBLE);
//Back button
String backId = "";
if(mIdList.size() > 1)
{
backId = mIdList.get(mIdList.size()-2);
btnBack.setVisibility(View.VISIBLE);
btnBack.setText(getActivityHeading(backId));
txtViewHeading.setPadding(10,0,0,0);
}
else
{
btnBack.setVisibility(View.GONE);
txtViewHeading.setPadding(0,0,0,0);
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
/**
* Starts an Activity as a child Activity to this.
* @param Id Unique identifier of the activity to be started.
* @param intent The Intent describing the activity to be started.
*/
public void startChildActivity(String Id, Intent intent)
{
try
{
btnShare.setVisibility(View.GONE);
Window window = getLocalActivityManager().startActivity(Id,intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
if (window != null)
{
mIdList.add(Id);
setContentView(window.getDecorView());
txtViewHeading.setText(getActivityHeading(Id));
//Back button
String backId = "";
if(mIdList.size() > 1)
{
backId = mIdList.get(mIdList.size()-2);
btnBack.setVisibility(View.VISIBLE);
btnBack.setText(backId);
txtViewHeading.setPadding(5,0,0,0);
}
else
{
btnBack.setVisibility(View.GONE);
txtViewHeading.setPadding(0,0,0,0);
}
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
/**
* The primary purpose is to prevent systems before android.os.Build.VERSION_CODES.ECLAIR
* from calling their default KeyEvent.KEYCODE_BACK during onKeyDown.
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_BACK)
{
//preventing default
return true;
}
return super.onKeyDown(keyCode, event);
}
/**
* Overrides the default implementation for KeyEvent.KEYCODE_BACK
* so that all systems call onBackPressed().
*/
@Override
public boolean onKeyUp(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_BACK)
{
onBackPressed();
return true;
}
return super.onKeyUp(keyCode, event);
}
/**
* If a Child Activity handles KeyEvent.KEYCODE_BACK.
* Simply override and add this method.
*/
@Override
public void onBackPressed ()
{
try
{
btnShare.setVisibility(View.GONE);
int length = mIdList.size();
if ( length > 1)
{
Activity current = getLocalActivityManager().getActivity(mIdList.get(length-1));
current.finish();
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
/**
* Get the correct heading text and language based on activity id
*/
public String getActivityHeading(String id)
{
// method that returns the TEXT for my main heading TextView based on the activity we're on...
}
}
状态组活动
public class StatusGroupActivity extends TabGroupActivity
{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
startChildActivity("Status", new Intent(this,Status.class));
}
}
...所以基本上当我的应用程序加载时，我的标签位于底部，标题位于顶部，“标签内容”位于中间。在我的状态活动中，我可以使用 ...
Intent intent = new Intent(getParent(), SomeOtherActivity.class)
TabGroupActivity parentActivity = (TabGroupActivity)getParent();
parentActivity.startChildActivity("Some Other Activity", intent);
...并将 SomeOtherActivity 活动加载到内容区域。回击让我回到状态屏幕。
非常感谢任何将其转换为使用 Fragments 的指针、示例和帮助。我很乐意捐赠我的 500 个代表。一个完整的例子。
main.xml（主活动布局文件）
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.app.FragmentTabHost xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true"
tools:ignore="ContentDescription,HardcodedText" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="@+id/imageSuccess"
android:layout_width="wrap_content"
android:layout_height="40dp"
android:adjustViewBounds="true"
android:scaleType="matrix"
android:src="@drawable/bg_navbar_blank" />
<com.myproject.android.BgButtonStyle
android:id="@+id/btnBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginTop="0dp"
android:background="@drawable/back_button"
android:text=""
android:textColor="@color/White"
android:textSize="12sp"
android:visibility="visible"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:padding="5dp"/>
<ImageButton
android:id="@+id/btnShare"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="15dp"
android:background="@null"
android:src="@drawable/icon_share"
android:visibility="visible"
android:adjustViewBounds="false"
android:scaleType="fitXY"/>
<com.myproject.android.AutoResizeTextView
android:id="@+id/txtViewHeading"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:paddingLeft="5dp"
android:text="Status"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="28sp"
android:textStyle="bold"
android:paddingRight="5dp"
android:layout_toEndOf="@id/btnBack"
android:layout_toStartOf="@id/btnShare"
android:layout_centerVertical="true"
android:lines="1"/>
</RelativeLayout>
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1" >
</FrameLayout>
<TabWidget
android:id="@android:id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="-4dp"
android:layout_weight="0"
android:background="@drawable/bg_tabs">
</TabWidget>
</LinearLayout>
</android.support.v4.app.FragmentTabHost>
在我当前的 TabGroupActivity 类中，在 finishFromChild 和 startChildActivity 方法中，我可以在我的主要活动布局中的 txtViewHeading TextView 元素上调用 setText。这是当前活动的“标题”。如果组中有超过 1 个活动，则返回按钮显示上一个标题。如何在下面的示例中复制它？那里的主要活动布局与我的大不相同。