Java 变化扩展了活动的类别
你好，我正在尝试在android上创建我的第一个应用程序。很抱歉问了这么愚蠢的问题，但我绝望了 我在android studio中创建了一个带有空白活动的新应用程序 XML: 然后我想将活动的扩展类更改为ListActivity：Java 变化扩展了活动的类别,java,android,android-studio,Java,Android,Android Studio,你好，我正在尝试在android上创建我的第一个应用程序。很抱歉问了这么愚蠢的问题，但我绝望了 我在android studio中创建了一个带有空白活动的新应用程序 XML: 然后我想将活动的扩展类更改为ListActivity： public class MainActivity extends ListActivity { @Override protected void onCreate(Bundle savedInstanceState) { super
public class MainActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
.
.
.
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.kubitas.listviewapp" >
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
请帮助我。ListActivity必须在名为“@android:id/list”的活动中声明一个列表。这是使用ListActivity的要求。如果您没有真正使用ListActivity，则需要扩展Activity或AppCompatActivity。如果您确实想玩ListActivity，请将ListView添加到布局文件中，并将其命名为下面的名称 请参阅：
决定回答而不是评论：） 问题可能与以下事实有关：
ListActivityAppCompatActivityAppCompatActivityandroid.support.v4.app.ListFragment另一个问题可能是
ListActivityListViewListFragmentAppCompactListActivityAppCompactListActivityimport android.os.Handler;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
public abstract class AppCompatListActivity extends android.support.v7.app.AppCompatActivity {
static final int INTERNAL_EMPTY_ID = 0x00ff0001;
static final int INTERNAL_PROGRESS_CONTAINER_ID = 0x00ff0002;
static final int INTERNAL_LIST_CONTAINER_ID = 0x00ff0003;
final private Handler mHandler = new Handler();
final private Runnable mRequestFocus = new Runnable() {
public void run() {
mList.focusableViewAvailable(mList);
}
};
final private AdapterView.OnItemClickListener mOnClickListener
= new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
onListItemClick((ListView)parent, v, position, id);
}
};
ListAdapter mAdapter;
ListView mList;
View mEmptyView;
TextView mStandardEmptyView;
View mProgressContainer;
View mListContainer;
CharSequence mEmptyText;
boolean mListShown;
public AppCompatListActivity() {
}
/**
* Provide default implementation to return a simple list view. Subclasses
* can override to replace with their own layout. If doing so, the
* returned view hierarchy <em>must</em> have a ListView whose id
* is {@link android.R.id#list android.R.id.list} and can optionally
* have a sibling view id {@link android.R.id#empty android.R.id.empty}
* that is to be shown when the list is empty.
*
* <p>If you are overriding this method with your own custom content,
* consider including the standard layout {@link android.R.layout#list_content}
* in your layout file, so that you continue to retain all of the standard
* behavior of ListFragment. In particular, this is currently the only
* way to have the built-in indeterminant progress state be shown.
*/
/*
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
FrameLayout root = new FrameLayout(context);
// ------------------------------------------------------------------
LinearLayout pframe = new LinearLayout(context);
pframe.setId(INTERNAL_PROGRESS_CONTAINER_ID);
pframe.setOrientation(LinearLayout.VERTICAL);
pframe.setVisibility(View.GONE);
pframe.setGravity(Gravity.CENTER);
ProgressBar progress = new ProgressBar(context, null,
android.R.attr.progressBarStyleLarge);
pframe.addView(progress, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
root.addView(pframe, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
// ------------------------------------------------------------------
FrameLayout lframe = new FrameLayout(context);
lframe.setId(INTERNAL_LIST_CONTAINER_ID);
TextView tv = new TextView(getActivity());
tv.setId(INTERNAL_EMPTY_ID);
tv.setGravity(Gravity.CENTER);
lframe.addView(tv, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
ListView lv = new ListView(getActivity());
lv.setId(android.R.id.list);
lv.setDrawSelectorOnTop(false);
lframe.addView(lv, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
root.addView(lframe, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
// ------------------------------------------------------------------
root.setLayoutParams(new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
return root;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ensureList();
}
*/
/**
* Detach from list view.
*/
@Override
public void onDestroy() {
mHandler.removeCallbacks(mRequestFocus);
mList = null;
mListShown = false;
mEmptyView = mProgressContainer = mListContainer = null;
mStandardEmptyView = null;
super.onDestroy();
}
/**
* This method will be called when an item in the list is selected.
* Subclasses should override. Subclasses can call
* getListView().getItemAtPosition(position) if they need to access the
* data associated with the selected item.
*
* @param l The ListView where the click happened
* @param v The view that was clicked within the ListView
* @param position The position of the view in the list
* @param id The row id of the item that was clicked
*/
public void onListItemClick(ListView l, View v, int position, long id) {
}
/**
* Provide the cursor for the list view.
*/
public void setListAdapter(ListAdapter adapter) {
boolean hadAdapter = mAdapter != null;
mAdapter = adapter;
if (mList != null) {
mList.setAdapter(adapter);
if (!mListShown && !hadAdapter) {
// The list was hidden, and previously didn't have an
// adapter. It is now time to show it.
//setListShown(true, getView().getWindowToken() != null);
setListShown(true, false);
}
}
}
/**
* Set the currently selected list item to the specified
* position with the adapter's data
*
* @param position -
*/
public void setSelection(int position) {
ensureList();
mList.setSelection(position);
}
/**
* Get the position of the currently selected list item.
*/
public int getSelectedItemPosition() {
ensureList();
return mList.getSelectedItemPosition();
}
/**
* Get the cursor row ID of the currently selected list item.
*/
public long getSelectedItemId() {
ensureList();
return mList.getSelectedItemId();
}
/**
* Get the activity's list view widget.
*/
public ListView getListView() {
ensureList();
return mList;
}
/**
* The default content for a ListFragment has a TextView that can
* be shown when the list is empty. If you would like to have it
* shown, call this method to supply the text it should use.
*/
public void setEmptyText(CharSequence text) {
ensureList();
if (mStandardEmptyView == null) {
throw new IllegalStateException("Can't be used with a custom content view");
}
mStandardEmptyView.setText(text);
if (mEmptyText == null) {
mList.setEmptyView(mStandardEmptyView);
}
mEmptyText = text;
}
/**
* Control whether the list is being displayed. You can make it not
* displayed if you are waiting for the initial data to show in it. During
* this time an indeterminant progress indicator will be shown instead.
*
* <p>Applications do not normally need to use this themselves. The default
* behavior of ListFragment is to start with the list not being shown, only
* showing it once an adapter is given with {@link #setListAdapter(ListAdapter)}.
* If the list at that point had not been shown, when it does get shown
* it will be do without the user ever seeing the hidden state.
*
* @param shown If true, the list view is shown; if false, the progress
* indicator. The initial value is true.
*/
public void setListShown(boolean shown) {
setListShown(shown, true);
}
/**
* Like {@link #setListShown(boolean)}, but no animation is used when
* transitioning from the previous state.
*/
public void setListShownNoAnimation(boolean shown) {
setListShown(shown, false);
}
/**
* Control whether the list is being displayed. You can make it not
* displayed if you are waiting for the initial data to show in it. During
* this time an indeterminant progress indicator will be shown instead.
*
* @param shown If true, the list view is shown; if false, the progress
* indicator. The initial value is true.
* @param animate If true, an animation will be used to transition to the
* new state.
*/
private void setListShown(boolean shown, boolean animate) {
ensureList();
if (mProgressContainer == null) {
throw new IllegalStateException("Can't be used with a custom content view");
}
if (mListShown == shown) {
return;
}
mListShown = shown;
if (shown) {
if (animate) {
mProgressContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
mListContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
} else {
mProgressContainer.clearAnimation();
mListContainer.clearAnimation();
}
mProgressContainer.setVisibility(View.GONE);
mListContainer.setVisibility(View.VISIBLE);
} else {
if (animate) {
mProgressContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
mListContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
} else {
mProgressContainer.clearAnimation();
mListContainer.clearAnimation();
}
mProgressContainer.setVisibility(View.VISIBLE);
mListContainer.setVisibility(View.GONE);
}
}
/**
* Get the ListAdapter associated with this activity's ListView.
*/
public ListAdapter getListAdapter() {
return mAdapter;
}
private void ensureList() {
if (mList != null) {
return;
}
View root = findViewById(android.R.id.content).getRootView();
if (root == null) {
throw new IllegalStateException("Content view not yet created");
}
if (root instanceof ListView) {
mList = (ListView)root;
} else {
mStandardEmptyView = (TextView)root.findViewById(INTERNAL_EMPTY_ID);
if (mStandardEmptyView == null) {
mEmptyView = root.findViewById(android.R.id.empty);
} else {
mStandardEmptyView.setVisibility(View.GONE);
}
mProgressContainer = root.findViewById(INTERNAL_PROGRESS_CONTAINER_ID);
mListContainer = root.findViewById(INTERNAL_LIST_CONTAINER_ID);
View rawListView = root.findViewById(android.R.id.list);
if (!(rawListView instanceof ListView)) {
if (rawListView == null) {
throw new RuntimeException(
"Your content must have a ListView whose id attribute is " +
"'android.R.id.list'");
}
throw new RuntimeException(
"Content has view with id attribute 'android.R.id.list' "
+ "that is not a ListView class");
}
mList = (ListView)rawListView;
if (mEmptyView != null) {
mList.setEmptyView(mEmptyView);
} else if (mEmptyText != null) {
mStandardEmptyView.setText(mEmptyText);
mList.setEmptyView(mStandardEmptyView);
}
}
mListShown = true;
mList.setOnItemClickListener(mOnClickListener);
if (mAdapter != null) {
ListAdapter adapter = mAdapter;
mAdapter = null;
setListAdapter(adapter);
} else {
// We are starting without an adapter, so assume we won't
// have our data right away and start with the progress indicator.
if (mProgressContainer != null) {
setListShown(false, false);
}
}
mHandler.post(mRequestFocus);
}
}
导入android.os.Handler；
导入android.view.view；
导入android.view.animation.AnimationUtils；
导入android.widget.AdapterView；
导入android.widget.ListAdapter；
导入android.widget.ListView；
导入android.widget.TextView；
公共抽象类AppCompatListActivity扩展了android.support.v7.app.AppCompatActivity{
静态最终整数内部\u空\u ID=0x00ff0001；
静态最终内部进度容器ID=0x00ff0002；
静态最终内部列表容器ID=0x00ff0003；
最终私有处理程序mHandler=新处理程序（）；
最终私有可运行mRequestFocus=new Runnable（）{
公开募捐{
mList.focusableViewAvailable（mList）；
}
};
最终私有AdapterView.OnItemClickListener mOnClickListener
=新AdapterView.OnItemClickListener（）{
public void onItemClick（AdapterView父视图、视图v、整型位置、长id）{
onListItemClick（（ListView）父项、v、位置、id）；
}
};
列表适配器mAdapter；
ListView-mList；
查看mEmptyView；
文本视图mStandardEmptyView；
查看mProgressContainer；
查看mListContainer；
字符序列mEmptyText；
显示布尔值；
公共AppCompatiListActivity（）{
}
/**
*提供返回简单列表视图的默认实现
*可以重写以替换为自己的布局。如果这样做，则
*返回的视图层次结构必须具有id为的ListView
*是{@link android.R.id#list android.R.id.list}，可以选择
*具有同级视图id{@link android.R.id#empty android.R.id.empty}
*当列表为空时显示。
*
*如果要用自己的自定义内容覆盖此方法，
*考虑包括标准布局{@链接Android .r.Frase} ListSyth}
*在布局文件中，以便继续保留所有标准
*ListFragment的行为。特别是，这是当前唯一的
*显示内置不确定进度状态的方法。
*/
/*
@凌驾
CreateView上的公共视图（布局、充气机、视图组容器、捆绑包保存状态）{
FrameLayout root=新的FrameLayout（上下文）；
// ------------------------------------------------------------------
LinearLayout pframe=新的LinearLayout（上下文）；
pframe.setId（内部进程容器ID）；
pframe.设置方向（线性布局.垂直）；
pframe.setVisibility（View.GONE）；
pframe.setGravity（重心）；
ProgressBar进度=新的ProgressBar（上下文，null，
android.R.attr.progressBarStyleLarge）；
pframe.addView（进度，新的FrameLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_内容，ViewGroup.LayoutParams.WRAP_内容）；
root.addView（pframe，新FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_父级，ViewGroup.LayoutParams.FILL_父级）；
// ------------------------------------------------------------------
FrameLayout lframe=新的FrameLayout（上下文）；
lframe.setId（内部列表容器ID）；
TextView tv=新的TextView（getActivity（））；
tv.setId（内部\u空\u ID）；
电视。设置重力（重力。重心）；
lframe.addView（电视，新FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_父级，ViewGroup.LayoutParams.FILL_父级）；
ListView lv=新的ListView（getActivity（））；
lv.setId（android.R.id.list）；
lv.setDrawSelectorOnTop（假）；
lframe.addView（lv，新的FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_父级，ViewGroup.LayoutParams.FILL_父级）；
root.addView（lframe，new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_父级，ViewGroup.LayoutParams.FILL_父级）；
// ------------------------------------------------------------------
root.setLayoutParams（新的FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_父级，ViewGroup.LayoutParams.FILL_父级）；
返回根；
}
@凌驾
已创建视图上的公共void（视图，捆绑保存状态）{
super.onViewCreated（视图，savedInstanc
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.kubitas.listviewapp" >
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@android:id/list"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
public class MainActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
import android.os.Handler;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
public abstract class AppCompatListActivity extends android.support.v7.app.AppCompatActivity {
static final int INTERNAL_EMPTY_ID = 0x00ff0001;
static final int INTERNAL_PROGRESS_CONTAINER_ID = 0x00ff0002;
static final int INTERNAL_LIST_CONTAINER_ID = 0x00ff0003;
final private Handler mHandler = new Handler();
final private Runnable mRequestFocus = new Runnable() {
public void run() {
mList.focusableViewAvailable(mList);
}
};
final private AdapterView.OnItemClickListener mOnClickListener
= new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
onListItemClick((ListView)parent, v, position, id);
}
};
ListAdapter mAdapter;
ListView mList;
View mEmptyView;
TextView mStandardEmptyView;
View mProgressContainer;
View mListContainer;
CharSequence mEmptyText;
boolean mListShown;
public AppCompatListActivity() {
}
/**
* Provide default implementation to return a simple list view. Subclasses
* can override to replace with their own layout. If doing so, the
* returned view hierarchy <em>must</em> have a ListView whose id
* is {@link android.R.id#list android.R.id.list} and can optionally
* have a sibling view id {@link android.R.id#empty android.R.id.empty}
* that is to be shown when the list is empty.
*
* <p>If you are overriding this method with your own custom content,
* consider including the standard layout {@link android.R.layout#list_content}
* in your layout file, so that you continue to retain all of the standard
* behavior of ListFragment. In particular, this is currently the only
* way to have the built-in indeterminant progress state be shown.
*/
/*
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
FrameLayout root = new FrameLayout(context);
// ------------------------------------------------------------------
LinearLayout pframe = new LinearLayout(context);
pframe.setId(INTERNAL_PROGRESS_CONTAINER_ID);
pframe.setOrientation(LinearLayout.VERTICAL);
pframe.setVisibility(View.GONE);
pframe.setGravity(Gravity.CENTER);
ProgressBar progress = new ProgressBar(context, null,
android.R.attr.progressBarStyleLarge);
pframe.addView(progress, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
root.addView(pframe, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
// ------------------------------------------------------------------
FrameLayout lframe = new FrameLayout(context);
lframe.setId(INTERNAL_LIST_CONTAINER_ID);
TextView tv = new TextView(getActivity());
tv.setId(INTERNAL_EMPTY_ID);
tv.setGravity(Gravity.CENTER);
lframe.addView(tv, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
ListView lv = new ListView(getActivity());
lv.setId(android.R.id.list);
lv.setDrawSelectorOnTop(false);
lframe.addView(lv, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
root.addView(lframe, new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
// ------------------------------------------------------------------
root.setLayoutParams(new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
return root;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ensureList();
}
*/
/**
* Detach from list view.
*/
@Override
public void onDestroy() {
mHandler.removeCallbacks(mRequestFocus);
mList = null;
mListShown = false;
mEmptyView = mProgressContainer = mListContainer = null;
mStandardEmptyView = null;
super.onDestroy();
}
/**
* This method will be called when an item in the list is selected.
* Subclasses should override. Subclasses can call
* getListView().getItemAtPosition(position) if they need to access the
* data associated with the selected item.
*
* @param l The ListView where the click happened
* @param v The view that was clicked within the ListView
* @param position The position of the view in the list
* @param id The row id of the item that was clicked
*/
public void onListItemClick(ListView l, View v, int position, long id) {
}
/**
* Provide the cursor for the list view.
*/
public void setListAdapter(ListAdapter adapter) {
boolean hadAdapter = mAdapter != null;
mAdapter = adapter;
if (mList != null) {
mList.setAdapter(adapter);
if (!mListShown && !hadAdapter) {
// The list was hidden, and previously didn't have an
// adapter. It is now time to show it.
//setListShown(true, getView().getWindowToken() != null);
setListShown(true, false);
}
}
}
/**
* Set the currently selected list item to the specified
* position with the adapter's data
*
* @param position -
*/
public void setSelection(int position) {
ensureList();
mList.setSelection(position);
}
/**
* Get the position of the currently selected list item.
*/
public int getSelectedItemPosition() {
ensureList();
return mList.getSelectedItemPosition();
}
/**
* Get the cursor row ID of the currently selected list item.
*/
public long getSelectedItemId() {
ensureList();
return mList.getSelectedItemId();
}
/**
* Get the activity's list view widget.
*/
public ListView getListView() {
ensureList();
return mList;
}
/**
* The default content for a ListFragment has a TextView that can
* be shown when the list is empty. If you would like to have it
* shown, call this method to supply the text it should use.
*/
public void setEmptyText(CharSequence text) {
ensureList();
if (mStandardEmptyView == null) {
throw new IllegalStateException("Can't be used with a custom content view");
}
mStandardEmptyView.setText(text);
if (mEmptyText == null) {
mList.setEmptyView(mStandardEmptyView);
}
mEmptyText = text;
}
/**
* Control whether the list is being displayed. You can make it not
* displayed if you are waiting for the initial data to show in it. During
* this time an indeterminant progress indicator will be shown instead.
*
* <p>Applications do not normally need to use this themselves. The default
* behavior of ListFragment is to start with the list not being shown, only
* showing it once an adapter is given with {@link #setListAdapter(ListAdapter)}.
* If the list at that point had not been shown, when it does get shown
* it will be do without the user ever seeing the hidden state.
*
* @param shown If true, the list view is shown; if false, the progress
* indicator. The initial value is true.
*/
public void setListShown(boolean shown) {
setListShown(shown, true);
}
/**
* Like {@link #setListShown(boolean)}, but no animation is used when
* transitioning from the previous state.
*/
public void setListShownNoAnimation(boolean shown) {
setListShown(shown, false);
}
/**
* Control whether the list is being displayed. You can make it not
* displayed if you are waiting for the initial data to show in it. During
* this time an indeterminant progress indicator will be shown instead.
*
* @param shown If true, the list view is shown; if false, the progress
* indicator. The initial value is true.
* @param animate If true, an animation will be used to transition to the
* new state.
*/
private void setListShown(boolean shown, boolean animate) {
ensureList();
if (mProgressContainer == null) {
throw new IllegalStateException("Can't be used with a custom content view");
}
if (mListShown == shown) {
return;
}
mListShown = shown;
if (shown) {
if (animate) {
mProgressContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
mListContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
} else {
mProgressContainer.clearAnimation();
mListContainer.clearAnimation();
}
mProgressContainer.setVisibility(View.GONE);
mListContainer.setVisibility(View.VISIBLE);
} else {
if (animate) {
mProgressContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
mListContainer.startAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
} else {
mProgressContainer.clearAnimation();
mListContainer.clearAnimation();
}
mProgressContainer.setVisibility(View.VISIBLE);
mListContainer.setVisibility(View.GONE);
}
}
/**
* Get the ListAdapter associated with this activity's ListView.
*/
public ListAdapter getListAdapter() {
return mAdapter;
}
private void ensureList() {
if (mList != null) {
return;
}
View root = findViewById(android.R.id.content).getRootView();
if (root == null) {
throw new IllegalStateException("Content view not yet created");
}
if (root instanceof ListView) {
mList = (ListView)root;
} else {
mStandardEmptyView = (TextView)root.findViewById(INTERNAL_EMPTY_ID);
if (mStandardEmptyView == null) {
mEmptyView = root.findViewById(android.R.id.empty);
} else {
mStandardEmptyView.setVisibility(View.GONE);
}
mProgressContainer = root.findViewById(INTERNAL_PROGRESS_CONTAINER_ID);
mListContainer = root.findViewById(INTERNAL_LIST_CONTAINER_ID);
View rawListView = root.findViewById(android.R.id.list);
if (!(rawListView instanceof ListView)) {
if (rawListView == null) {
throw new RuntimeException(
"Your content must have a ListView whose id attribute is " +
"'android.R.id.list'");
}
throw new RuntimeException(
"Content has view with id attribute 'android.R.id.list' "
+ "that is not a ListView class");
}
mList = (ListView)rawListView;
if (mEmptyView != null) {
mList.setEmptyView(mEmptyView);
} else if (mEmptyText != null) {
mStandardEmptyView.setText(mEmptyText);
mList.setEmptyView(mStandardEmptyView);
}
}
mListShown = true;
mList.setOnItemClickListener(mOnClickListener);
if (mAdapter != null) {
ListAdapter adapter = mAdapter;
mAdapter = null;
setListAdapter(adapter);
} else {
// We are starting without an adapter, so assume we won't
// have our data right away and start with the progress indicator.
if (mProgressContainer != null) {
setListShown(false, false);
}
}
mHandler.post(mRequestFocus);
}
}