在使用My Application类时在android中有classcastexception
我在做什么 ::我正在尝试使用Myapplication类将数据发送到下一个活动
我面临的问题 ::有类投射异常
BLD_IndividualListOfItems_Starters.java
public class BLD_IndividualListOfItems_Starters extends Activity{
// Declare Variables
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapterForAtomicListItemtype adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
static String NAME = "rank";
Button btn;
String TYPE_FILTER;
StringBuilder result;
MyApplication mApplication;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mApplication = (MyApplication)getApplication();
// Get the view from listview_main.xml
setContentView(R.layout.listview_main);
TYPE_FILTER = getIntent().getExtras().getString("key_title");
Log.v("---- Value-Start---", TYPE_FILTER);
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
result = new StringBuilder();
for (int i = 0; i < arraylist.size(); i++) {
if (adapter.mysparse.get(i) == true) {
result.append(arraylist.get(i).get(BLD_IndividualListOfItems_Starters.NAME));
result.append("\n");
}
}
Intent n = new Intent(BLD_IndividualListOfItems_Starters.this, ResultActivity.class);
n.putExtra("buffer", result.toString());
startActivity(n);
}
});
// Execute DownloadJSON AsyncTask
new DownloadJSON().execute();
}
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(BLD_IndividualListOfItems_Starters.this);
// Set progressdialog title
//mProgressDialog.setTitle("Fetching the information");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
String newurl = "?" + "Key=" + TYPE_FILTER;
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions.getJSONfromURL("http://54.218.73.244:7005/RestaurantAtomicListItemType/"+newurl);
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("restaurants");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
map.put(BLD_IndividualListOfItems_Starters.NAME, jsonobject.getString("MasterListMenuName"));
// Set the JSON Objects into the array
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapterForAtomicListItemtype(BLD_IndividualListOfItems_Starters.this, arraylist);
// Set the adapter to the ListView
mApplication.setArrayListMapData(arraylist);
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
}
}
}
ResultActivity.java
public class ResultActivity extends ListActivity {
ListView lstView;
ArrayList<HashMap<String,String>> arraylist = new ArrayList<HashMap<String,String>>();
String myName;
MyApplication mApplication;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
for(int i=0;i<10;i++)
{
HashMap<String,String> map = new HashMap<String,String>();
map.put("key", "value"+i);
arraylist.add(map);
}
String[] from = { "key" };
int[] to = { R.id.textView1 };
SimpleAdapter adapter= new SimpleAdapter(this, arraylist,R.layout.custom_single_list, from, to);
setListAdapter(adapter);
}
}
清单
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.multitabcheckboxselection"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_MainCourse" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_SideCourse" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Others" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Desert" />
<activity android:name="com.example.multitabcheckboxselection.ResultActivity" />
</application>
<application
android:name="com.android.app.MyApplication"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
</application>
</manifest>
ListViewAdapterForAtomicListItemtype.java
public class ListViewAdapterForAtomicListItemtype extends BaseAdapter implements OnCheckedChangeListener {
// Declare Variables
Context context;
LayoutInflater inflater;
ArrayList<HashMap<String, String>> data;
HashMap<String, String> resultp = new HashMap<String, String>();
SparseBooleanArray mysparse;
public ListViewAdapterForAtomicListItemtype(Context context,
ArrayList<HashMap<String, String>> arraylist) {
this.context = context;
data = arraylist;
mysparse = new SparseBooleanArray(data.size());
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
public View getView(final int position, View convertView, ViewGroup parent) {
// Declare Variables
TextView name;
CheckBox chk;
inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.listview_item_for_atomic_list_item_type, parent, false);
// Get the position
resultp = data.get(position);
// Locate the TextViews in listview_item.xml
name = (TextView) itemView.findViewById(R.id.textView_id_atomic_list_item_type);
chk = (CheckBox) itemView.findViewById(R.id.checkBox_atomic_list_item_type_id);
// Capture position and set results to the TextViews
name.setText(resultp.get(BLD_IndividualListOfItems_Starters.NAME));
chk.setTag(position);
chk.setChecked(mysparse.get(position, false));
chk.setOnCheckedChangeListener(this);
return itemView;
}
public boolean isChecked(int position) {
return mysparse.get(position, false);
}
public void setChecked(int position, boolean isChecked) {
mysparse.put(position, isChecked);
}
public void toggle(int position) {
setChecked(position, !isChecked(position));
}
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
mysparse.put((Integer) buttonView.getTag(), isChecked);
}
}
日志 ::
01-03 13:30:12.828: D/AndroidRuntime(461): Shutting down VM
01-03 13:30:12.828: W/dalvikvm(461): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
01-03 13:30:12.868: E/AndroidRuntime(461): FATAL EXCEPTION: main
01-03 13:30:12.868: E/AndroidRuntime(461): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.multitabcheckboxselection/com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems}: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.multitabcheckboxselection/com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters}: java.lang.ClassCastException: android.app.Application
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.os.Handler.dispatchMessage(Handler.java:99)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.os.Looper.loop(Looper.java:123)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.main(ActivityThread.java:4627)
01-03 13:30:12.868: E/AndroidRuntime(461): at java.lang.reflect.Method.invokeNative(Native Method)
01-03 13:30:12.868: E/AndroidRuntime(461): at java.lang.reflect.Method.invoke(Method.java:521)
01-03 13:30:12.868: E/AndroidRuntime(461): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-03 13:30:12.868: E/AndroidRuntime(461): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-03 13:30:12.868: E/AndroidRuntime(461): at dalvik.system.NativeStart.main(Native Method)
01-03 13:30:12.868: E/AndroidRuntime(461): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.multitabcheckboxselection/com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters}: java.lang.ClassCastException: android.app.Application
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:651)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.widget.TabHost.setCurrentTab(TabHost.java:323)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.widget.TabHost.addTab(TabHost.java:213)
01-03 13:30:12.868: E/AndroidRuntime(461): at com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems.onCreate(BreakfastLunchDinnerIndividualListOfItems.java:36)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-03 13:30:12.868: E/AndroidRuntime(461): ... 11 more
01-03 13:30:12.868: E/AndroidRuntime(461): Caused by: java.lang.ClassCastException: android.app.Application
01-03 13:30:12.868: E/AndroidRuntime(461): at com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters.onCreate(BLD_IndividualListOfItems_Starters.java:47)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-03 13:30:12.868: E/AndroidRuntime(461): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-03 13:30:12.868: E/AndroidRuntime(461): ... 20 more
01-03 13:30:15.563: I/Process(461): Sending signal. PID: 461 SIG: 9
{编辑}
BLD_IndividualListOfItems_Starters.java
public class BLD_IndividualListOfItems_Starters extends Activity{
// Declare Variables
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapterForAtomicListItemtype adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
static String NAME = "rank";
Button btn;
String TYPE_FILTER;
StringBuilder result;
MyApplication mApplication;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mApplication = (MyApplication)getApplicationContext();
// Get the view from listview_main.xml
setContentView(R.layout.listview_main);
TYPE_FILTER = getIntent().getExtras().getString("key_title");
Log.v("---- Value-Start---", TYPE_FILTER);
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
result = new StringBuilder();
for (int i = 0; i < arraylist.size(); i++) {
if (adapter.mysparse.get(i) == true) {
result.append(arraylist.get(i).get(BLD_IndividualListOfItems_Starters.NAME));
result.append("\n");
}
}
Intent n = new Intent(BLD_IndividualListOfItems_Starters.this, ResultActivity.class);
n.putExtra("buffer", result.toString());
startActivity(n);
}
});
// Execute DownloadJSON AsyncTask
new DownloadJSON().execute();
}
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(BLD_IndividualListOfItems_Starters.this);
// Set progressdialog title
//mProgressDialog.setTitle("Fetching the information");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
String newurl = "?" + "Key=" + TYPE_FILTER;
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions.getJSONfromURL("http://54.218.73.244:7005/RestaurantAtomicListItemType/"+newurl);
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("restaurants");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
map.put(BLD_IndividualListOfItems_Starters.NAME, jsonobject.getString("MasterListMenuName"));
// Set the JSON Objects into the array
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapterForAtomicListItemtype(BLD_IndividualListOfItems_Starters.this, arraylist);
// Set the adapter to the ListView
mApplication.setArrayListMapData(arraylist);
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
}
}
}
MyApplication.java
package com.example.multitabcheckboxselection;
import java.util.ArrayList;
import java.util.HashMap;
import android.app.Application;
public class MyApplication extends Application {
ArrayList<HashMap<String, String>> arraylist;
@Override
public void onCreate() {
super.onCreate();
}
public void setArrayListMapData(ArrayList<HashMap<String, String>> setData)
{
arraylist = setData;
}
public ArrayList<HashMap<String, String>> getArrayListMapData()
{
return arraylist;
}
}
{编辑-3}
清单
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.multitabcheckboxselection"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_MainCourse" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_SideCourse" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Others" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Desert" />
<activity android:name="com.example.multitabcheckboxselection.ResultActivity" />
</application>
<application
android:allowBackup="true"
android:name="com.example.multitabcheckboxselection.MyApplication"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
</application>
</manifest>
MyApplication.java
package com.example.multitabcheckboxselection;
import java.util.ArrayList;
import java.util.HashMap;
import android.app.Application;
public class MyApplication extends Application {
ArrayList<HashMap<String, String>> arraylist;
@Override
public void onCreate() {
super.onCreate();
}
public void setArrayListMapData(ArrayList<HashMap<String, String>> setData)
{
arraylist = setData;
}
public ArrayList<HashMap<String, String>> getArrayListMapData()
{
return arraylist;
}
}
日志 ::
01-03 14:13:14.509: E/AndroidRuntime(681): FATAL EXCEPTION: main
01-03 14:13:14.509: E/AndroidRuntime(681): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.multitabcheckboxselection/com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems}: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.multitabcheckboxselection/com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters}: java.lang.ClassCastException: android.app.Application
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.os.Handler.dispatchMessage(Handler.java:99)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.os.Looper.loop(Looper.java:123)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.main(ActivityThread.java:4627)
01-03 14:13:14.509: E/AndroidRuntime(681): at java.lang.reflect.Method.invokeNative(Native Method)
01-03 14:13:14.509: E/AndroidRuntime(681): at java.lang.reflect.Method.invoke(Method.java:521)
01-03 14:13:14.509: E/AndroidRuntime(681): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-03 14:13:14.509: E/AndroidRuntime(681): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-03 14:13:14.509: E/AndroidRuntime(681): at dalvik.system.NativeStart.main(Native Method)
01-03 14:13:14.509: E/AndroidRuntime(681): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.multitabcheckboxselection/com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters}: java.lang.ClassCastException: android.app.Application
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:651)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.widget.TabHost.setCurrentTab(TabHost.java:323)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.widget.TabHost.addTab(TabHost.java:213)
01-03 14:13:14.509: E/AndroidRuntime(681): at com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems.onCreate(BreakfastLunchDinnerIndividualListOfItems.java:36)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-03 14:13:14.509: E/AndroidRuntime(681): ... 11 more
01-03 14:13:14.509: E/AndroidRuntime(681): Caused by: java.lang.ClassCastException: android.app.Application
01-03 14:13:14.509: E/AndroidRuntime(681): at com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters.onCreate(BLD_IndividualListOfItems_Starters.java:47)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-03 14:13:14.509: E/AndroidRuntime(681): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
01-03 14:13:14.509: E/AndroidRuntime(681): ... 20 more
4 个答案:
答案 0 :(得分：1)
更改为
mApplication = (MyApplication)getApplicationContext();
编辑：
删除第二个应用程序标记并将其移至第一个
android:name="com.android.app.MyApplication"
编辑：
public class MyApplication extends Application {
private static MyApplication singleton;
public MyApplication getInstance(){
return singleton;
}
public void onCreate() {
super.onCreate();
singleton = this;
}
// other methods
}
然后在活动
mApplication = MyApplication.getInstance();
示例：
public class Main extends Activity{
ArrayList<HashMap<String,String>> arraylist = new ArrayList<HashMap<String,String>>();
MyApplication mapp;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapp = MyApplication.getInstance();
TextView tv = (TextView) findViewById(R.id.textView1);
tv.setText("My String from Application class is"+mapp.hello);
for(int i=0;i<10;i++)
{
HashMap<String,String> map = new HashMap<String,String>();
map.put("key", "value"+i);
arraylist.add(map);
}
mapp.setArrayListMapData(arraylist);
Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
startActivity(new Intent(Main.this,MainActivity.class));
}
});
}
main.xml中
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="51dp"
android:text="TextView" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="Button" />
</RelativeLayout>
MainActivity
public class MainActivity extends ListActivity
{
ListView lstView;
ArrayList<HashMap<String,String>> arraylist;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
MyApplication mApplication = MyApplication.getInstance();
Log.i("................",""+mApplication.hello);
lstView = getListView();
lstView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
arraylist= mApplication.getArrayListMapData();
String[] from = { "key" };
int[] to = { R.id.textView1 };
SimpleAdapter adapter= new SimpleAdapter(this, arraylist,R.layout.row, from, to);
setListAdapter(adapter);
}
}
所有MyApplication
public class MyApplication extends Application {
ArrayList<HashMap<String, String>> arraylist;
private static MyApplication instance = null;
public String hello= "Hello global Application";
@Override
public void onCreate() {
super.onCreate();
}
public static MyApplication getInstance() {
if(instance == null) {
instance = new MyApplication();
}
return instance;
}
public void setArrayListMapData(ArrayList<HashMap<String, String>> setData)
{
arraylist = setData;
}
public ArrayList<HashMap<String, String>> getArrayListMapData()
{
return arraylist;
}
}
清单文件
<application
android:allowBackup="true"
android:name="com.example.testlistactivity.MyApplication"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.testlistactivity.Main"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.testlistactivity.MainActivity"
android:label="@string/app_name" >
</activity>
</application>
Snap1
Snap2
答案 1 :(得分：1)
移动属性
android:name="com.android.app.MyApplication"
清单中的第一个application元素，并删除第二个application元素。
顺便说一下。你的MyApplication课程真的在com.android.app包中吗？
编辑：你使用不同的包，所以该行应
android:name="com.example.multitabcheckboxselection.MyApplication"
EDIT2 + 3：你现在把它作为一项活动。删除活动后，该属性必须转到application代码。
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.multitabcheckboxselection"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:name="com.example.multitabcheckboxselection.MyApplication"
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.multitabcheckboxselection.BreakfastLunchDinnerIndividualListOfItems"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Starters" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_MainCourse" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_SideCourse" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Others" />
<activity android:name="com.example.multitabcheckboxselection.BLD_IndividualListOfItems_Desert" />
<activity android:name="com.example.multitabcheckboxselection.ResultActivity" />
</application>
</manifest>
答案 2 :(得分：1)
通常会有人这样做
class MyApplication extends Application {
@Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
static public MyApplication getInstance() { return mInstance; }
static private MyApplication mInstance;
}
然后从其他地方
MyApplication myApp = MyApplication.getInstance();
答案 3 :(得分：1)
更改
mApplication = (MyApplication)getApplication();
要
mApplication = ((MyApplication) getApplicationContext());
在Manifest.xml中定义android:name="MyApplication"
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme"
android:name="MyApplication" >
修改
删除此
<application
android:name="com.android.app.MyApplication"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
</application>
每个应用程序只有一个<application>标记
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