本文介绍了安卓：从ArrayList中的Hashmap单获取价值？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
所以基本上，我有一个使用Hashmapping的数据库。
我运行一个查询后，我想输出的ID，并将其存储在另一个活动的数组。
在那之后，我想从数组访问一个元素。
下面是我的code数据库
公开的ArrayList＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; getIDList（）{
ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; = IDList表的ArrayList新LT＆;＆HashMap的LT;字符串，字符串＆GT;＆GT;（）;
字符串selectQuery =SELECT CardId中FROM抽认卡;
SQLiteDatabase数据库= this.getWritableDatabase（）; 光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{HashMap的＆LT;字符串，字符串＆GT; cardMap =新的HashMap＆LT;字符串，字符串＆GT;（）;
cardMap.put（CardId中，cursor.getString（0））;
IDList.add（cardMap）; }而（cursor.moveToNext（））;
}
返回IDList表;
这是code，其中我想访问的元素。在这种情况下，我想访问的第一要素。但是，一个误差
@覆盖
保护无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.activity_flashcards_random）;
TextView的currentID =（的TextView）findViewById（R.id.currentIdText）;
ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; IDList表= dbTools.getIDList（）;
currentID.setText（（IDList.get（0））的toString（））;}
有什么建议？
编辑：根据要求更多code。
这是DB工具code
包com.izulki.flipper;进口的java.util.ArrayList;
进口的java.util.HashMap;进口android.content.ContentValues;
进口android.content.Context;
进口android.database.Cursor;
进口android.database.sqlite.SQLiteDatabase;
进口android.database.sqlite.SQLiteOpenHelper;公共类的DBTools扩展SQLiteOpenHelper {
公共DBTool中（上下文的applicationContext）{
超（ApplicationContext一flashcards.db，NULL，1）;
} 字符串数据库名=闪卡; @覆盖
公共无效的onCreate（SQLiteDatabase数据库）{
查询字符串=CREATE TABLE卡片（CardId中INTEGER PRIMARY KEY，问题VARCHAR，VARCHAR回答，主题VARCHAR，INTEGER回答，正确INTEGER）;
database.execSQL（查询）; } @覆盖
公共无效onUpgrade（SQLiteDatabase数据库，诠释oldVersiom，诠释静态网页）{
查询字符串=DROP TABLE IF EXISTS抽认卡; database.execSQL（查询）;
的onCreate（数据库）; } 公共布尔checkCard（字符串CardId中）{
SQLiteDatabase数据库= this.getReadableDatabase（）;
光标光标= database.rawQuery（SELECT * FROM WHERE卡片= CardId中？，新的String [] {CardId中}）;
布尔存在=（cursor.getCount（）大于0）;
cursor.close（）;
返回的存在; } 公共无效insertCard（HashMap的＆LT;字符串，字符串＆GT; queryValues）{ SQLiteDatabase数据库= this.getWritableDatabase（）;
ContentValues值=新ContentValues（）;
values.put（问题，queryValues.get（问题））;
values.put（答案，queryValues.get（答案））;
values.put（主体，queryValues.get（主体））;
values.put（回答，0）;
values.put（正确的，0）; database.insert（闪卡，空，价值）;
database.close（）; } 公众诠释getCardsCount（）{
字符串countQuery =SELECT * FROM抽认卡;
SQLiteDatabase卡片= this.getReadableDatabase（）;
光标光标= flashcards.rawQuery（countQuery，NULL）;
INT CNT = cursor.getCount（）;
cursor.close（）;
返回CNT;
}
公众诠释updateCard（HashMap的＆LT;字符串，字符串＆GT; queryValues）{
SQLiteDatabase数据库= this.getWritableDatabase（）;
ContentValues值=新ContentValues（）;
values.put（问题，queryValues.get（问题））;
values.put（答案，queryValues.get（答案））;
values.put（主体，queryValues.get（主体））;
返回database.update（闪卡，价值观念，
CardId中+=？，新的String [] {queryValues.get（CardId中）}）;
} 公共无效resetCardStatistics（INT CardId中）{
SQLiteDatabase数据库= this.getWritableDatabase（）;
字符串resetQuery =UPDATE卡片SET回答= 0，正确= 0 WHERE CardId中='+ CardId中+';
database.execSQL（resetQuery）;
}
公共无效deleteAllCards（）{
SQLiteDatabase数据库= this.getWritableDatabase（）;
字符串deleteQuery =删除卡片;
database.execSQL（deleteQuery）; } 公共无效deleteCard（INT CardId中）{
SQLiteDatabase数据库= this.getWritableDatabase（）;
字符串deleteQuery =DELETE FROM WHERE卡片CardId中='+ CardId中+';
database.execSQL（deleteQuery）; } 公众的ArrayList＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; getAllCards（）{
ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; cardArrayList =新的ArrayList＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT;（）;
字符串selectQuery =SELECT * FROM卡片ORDER BY主题;
SQLiteDatabase数据库= this.getWritableDatabase（）; 光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{
HashMap的＆LT;字符串，字符串＆GT; cardMap =新的HashMap＆LT;字符串，字符串＆GT;（）;
cardMap.put（CardId中，cursor.getString（0））;
cardMap.put（问题，cursor.getString（1））;
cardMap.put（答案，cursor.getString（2））;
cardMap.put（主体，cursor.getString（3））; cardArrayList.add（cardMap）;
}而（cursor.moveToNext（））;
}
返回cardArrayList;
} 公众的ArrayList＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; getCardsSubject（字符串subjectSearch）{
ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; subjectList =新的ArrayList＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT;（）;
字符串selectQuery =SELECT CardId中从卡片WHERE主题='+ subjectSearch +';
SQLiteDatabase数据库= this.getWritableDatabase（）; 光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{HashMap的＆LT;字符串，字符串＆GT; cardMap =新的HashMap＆LT;字符串，字符串＆GT;（）;
cardMap.put（CardId中，cursor.getString（0））;
subjectList.add（cardMap）; }而（cursor.moveToNext（））;
}
返回subjectList; } 公众的ArrayList＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; getIDList（）{
ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; = IDList表的ArrayList新LT＆;＆HashMap的LT;字符串，字符串＆GT;＆GT;（）;
字符串selectQuery =SELECT CardId中FROM抽认卡;
SQLiteDatabase数据库= this.getWritableDatabase（）; 光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{HashMap的＆LT;字符串，字符串＆GT; cardMap =新的HashMap＆LT;字符串，字符串＆GT;（）;
cardMap.put（CardId中，cursor.getString（0））;
IDList.add（cardMap）; }而（cursor.moveToNext（））;
}
返回IDList表; } 公众的HashMap＆LT;字符串，字符串＆GT; getQuestionFromID（INT randomID）{
HashMap的＆LT;字符串，字符串＆GT; questionFinal =新的HashMap＆LT;字符串，字符串＆GT;（）;
SQLiteDatabase数据库= this.getReadableDatabase（）;
字符串selectQuery ='+ randomID +从卡片WHERE CardId中=选择问题：';
光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{
questionFinal.put（问题，cursor.getString（0））;
}而（cursor.moveToNext（））;
}
返回questionFinal;
} 公众的HashMap＆LT;字符串，字符串＆GT; getAnswerFromID（INT randomID）{
HashMap的＆LT;字符串，字符串＆GT; answerFinal =新的HashMap＆LT;字符串，字符串＆GT;（）;
SQLiteDatabase数据库= this.getReadableDatabase（）;
字符串selectQuery =SELECT回答卡片WHERE CardId中='+ randomID +';
光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{
answerFinal.put（答案，cursor.getString（0））;
}而（cursor.moveToNext（））;
}
返回answerFinal;
} 公共无效incrementCorrect（INT ID）{
SQLiteDatabase数据库= this.getWritableDatabase（）;
字符串incrementQuery =UPDATE卡片设置正确的=正确+1 WHERE CardId中='+身份证+';
database.execSQL（incrementQuery）;
} 公共无效incrementAnswered（INT randomID）{
SQLiteDatabase数据库= this.getWritableDatabase（）;
字符串incrementQuery =UPDATE卡片SET回答=回答+1 WHERE CardId中='+ randomID +';
database.execSQL（incrementQuery）;
} 公众的HashMap＆LT;字符串，字符串＆GT; getCardInfo（INT randomID）{
HashMap的＆LT;字符串，字符串＆GT; cardMap =新的HashMap＆LT;字符串，字符串＆GT;（）;
SQLiteDatabase数据库= this.getReadableDatabase（）;
字符串selectQuery =SELECT * FROM WHERE卡片CardId中='+ randomID +'; 光标光标= database.rawQuery（selectQuery，NULL）;
如果（cursor.moveToFirst（））{
做{ cardMap.put（CardId中，cursor.getString（0））;
cardMap.put（问题，cursor.getString（1））;
cardMap.put（答案，cursor.getString（2））;
cardMap.put（主体，cursor.getString（3））;
cardMap.put（回答，cursor.getString（4））;
cardMap.put（正确的，cursor.getString（5））; }而（cursor.moveToNext（））;
}
返回cardMap; }
}
这是活动code
包com.izulki.flipper;进口的java.util.ArrayList;
进口的java.util.HashMap;进口android.os.Bundle;
进口android.app.Activity;
进口android.view.Menu;
进口android.widget.TextView;
进口android.widget.Toast;公共类FlashcardsAnswer延伸活动{ DBTool中的DBTools =新的DBTools（本）; @覆盖
保护无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.activity_flashcards_random）;
TextView的currentID =（的TextView）findViewById（R.id.currentIdText）;
ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; IDList表= dbTools.getIDList（）;
currentID.setText（（IDList.get（0））的toString（））; } @覆盖
公共布尔onCreateOptionsMenu（菜单菜单）{
//充气菜单;如果是present这增加了项目操作栏。
。getMenuInflater（）膨胀（R.menu.flashcards_answer，菜单）;
返回true;
}}
这是错误
15 02-21：02：55.777：E / AndroidRuntime（1827）：致命异常：主要
02-21 15：02：55.777：E / AndroidRuntime（1827）：了java.lang.RuntimeException：无法实例化应用android.app.Application：java.lang.IllegalStateException：无法获取包信息的com.izulki.flipper;包是没有安装？
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.LoadedApk.makeApplication（LoadedApk.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.ActivityThread.handleBindApplication（ActivityThread.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.ActivityThread.access $ 1300（ActivityThread.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.ActivityThread $ H.handleMessage（ActivityThread.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.os.Handler.dispatchMessage（Handler.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.os.Looper.loop（Looper.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.ActivityThread.main（ActivityThread.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在java.lang.reflect.Method.invokeNative（本机方法）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在java.lang.reflect.Method.invoke（Method.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在com.android.internal.os.ZygoteInit.main（ZygoteInit.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在dalvik.system.NativeStart.main（本机方法）
02-21 15：02：55.777：E / AndroidRuntime（1827）：java.lang.IllegalStateException：产生的原因无法获取包信息的com.izulki.flipper;包是没有安装？
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.LoadedApk.initializeJavaContextClassLoader（LoadedApk.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：在android.app.LoadedApk.getClassLoader（LoadedApk.java）
02-21 15：02：55.777：E / AndroidRuntime（1827）：12 ...更多
解决方案
试试这个：
对（HashMap的＆LT;字符串，字符串＆GT;图：IDList表）
对于（进入＆LT;字符串，字符串＆GT; mapEntry：map.entrySet（））
{
字符串键= mapEntry.getKey（）;
字符串值= mapEntry.getValue（）;
}
有关单个元素： IDList.get（0）获得（键）;
So basically, I have a database that uses Hashmapping.After I run a query, I'd like to output the ID's and store it in an array in another activity.After that, I'd like to access a single element from the array.
Here's my code for the database
public ArrayList<HashMap<String, String>> getIDList() {
ArrayList<HashMap<String, String>> IDList = new ArrayList<HashMap<String, String>>();
String selectQuery = "SELECT cardID FROM flashcards";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()) {
do { HashMap<String, String> cardMap = new HashMap<String, String>();
cardMap.put("cardID", cursor.getString(0));
IDList.add(cardMap);
} while(cursor.moveToNext());
}
return IDList;
This is the code where I am trying to access the elements. In this case, I'd like to access the first element. But an error
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_flashcards_random);
TextView currentID = (TextView) findViewById(R.id.currentIdText);
ArrayList<HashMap<String, String>> IDList = dbTools.getIDList();
currentID.setText((IDList.get(0)).toString());
}
any suggestions?
EDIT: More code as requested.
This is DB Tools code
package com.izulki.flipper;
import java.util.ArrayList;
import java.util.HashMap;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBTools extends SQLiteOpenHelper {
public DBTools(Context applicationContext){
super(applicationContext, "flashcards.db", null, 1);
}
String DBName = "flashcards";
@Override
public void onCreate(SQLiteDatabase database) {
String query = "CREATE TABLE flashcards (cardID INTEGER PRIMARY KEY, question VARCHAR, answer VARCHAR, subject VARCHAR, answered INTEGER, correct INTEGER)";
database.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase database, int oldVersiom, int newVersion) {
String query = "DROP TABLE IF EXISTS flashcards";
database.execSQL(query);
onCreate(database);
}
public boolean checkCard(String CardID) {
SQLiteDatabase database = this.getReadableDatabase();
Cursor cursor = database.rawQuery("SELECT * FROM flashcards WHERE CardID = ? ", new String[]{CardID});
boolean exists = (cursor.getCount() > 0);
cursor.close();
return exists;
}
public void insertCard(HashMap<String, String> queryValues) {
SQLiteDatabase database = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("question", queryValues.get("question"));
values.put("answer", queryValues.get("answer"));
values.put("subject", queryValues.get("subject"));
values.put("answered", 0);
values.put("correct", 0);
database.insert("flashcards", null, values);
database.close();
}
public int getCardsCount() {
String countQuery = "SELECT * FROM flashcards";
SQLiteDatabase flashcards = this.getReadableDatabase();
Cursor cursor = flashcards.rawQuery(countQuery, null);
int cnt = cursor.getCount();
cursor.close();
return cnt;
}
public int updateCard(HashMap<String, String> queryValues) {
SQLiteDatabase database = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("question", queryValues.get("question"));
values.put("answer", queryValues.get("answer"));
values.put("subject", queryValues.get("subject"));
return database.update("flashcards", values,
"cardID" + " =?", new String[] {queryValues.get("cardID")});
}
public void resetCardStatistics(int cardID) {
SQLiteDatabase database = this.getWritableDatabase();
String resetQuery = "UPDATE flashcards SET answered = 0, correct = 0 WHERE CardID ='" + cardID + "'";
database.execSQL(resetQuery);
}
public void deleteAllCards() {
SQLiteDatabase database = this.getWritableDatabase();
String deleteQuery = "Delete FROM flashcards";
database.execSQL(deleteQuery);
}
public void deleteCard(int cardID) {
SQLiteDatabase database = this.getWritableDatabase();
String deleteQuery = "DELETE FROM flashcards WHERE CardID ='" + cardID + "'";
database.execSQL(deleteQuery);
}
public ArrayList<HashMap<String, String>> getAllCards(){
ArrayList<HashMap<String, String>> cardArrayList = new ArrayList<HashMap<String, String>>();
String selectQuery = "SELECT * FROM flashcards ORDER BY subject";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()){
do{
HashMap<String, String> cardMap = new HashMap<String, String>();
cardMap.put("cardID", cursor.getString(0));
cardMap.put("question", cursor.getString(1));
cardMap.put("answer", cursor.getString(2));
cardMap.put("subject", cursor.getString(3));
cardArrayList.add(cardMap);
} while(cursor.moveToNext());
}
return cardArrayList;
}
public ArrayList<HashMap<String, String>> getCardsSubject(String subjectSearch) {
ArrayList<HashMap<String, String>> subjectList = new ArrayList<HashMap<String, String>>();
String selectQuery = "SELECT cardID FROM flashcards WHERE subject = '" + subjectSearch + "'";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()) {
do { HashMap<String, String> cardMap = new HashMap<String, String>();
cardMap.put("cardID", cursor.getString(0));
subjectList.add(cardMap);
} while(cursor.moveToNext());
}
return subjectList;
}
public ArrayList<HashMap<String, String>> getIDList() {
ArrayList<HashMap<String, String>> IDList = new ArrayList<HashMap<String, String>>();
String selectQuery = "SELECT cardID FROM flashcards";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()) {
do { HashMap<String, String> cardMap = new HashMap<String, String>();
cardMap.put("cardID", cursor.getString(0));
IDList.add(cardMap);
} while(cursor.moveToNext());
}
return IDList;
}
public HashMap<String, String> getQuestionFromID(int randomID) {
HashMap<String, String> questionFinal = new HashMap<String, String>();
SQLiteDatabase database = this.getReadableDatabase();
String selectQuery = "SELECT question FROM flashcards WHERE cardID ='" + randomID + "'";
Cursor cursor = database.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do{
questionFinal.put("question", cursor.getString(0));
} while (cursor.moveToNext());
}
return questionFinal;
}
public HashMap<String, String> getAnswerFromID(int randomID) {
HashMap<String, String> answerFinal = new HashMap<String, String>();
SQLiteDatabase database = this.getReadableDatabase();
String selectQuery = "SELECT answer FROM flashcards WHERE cardID ='" + randomID + "'";
Cursor cursor = database.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do{
answerFinal.put("answer", cursor.getString(0));
} while (cursor.moveToNext());
}
return answerFinal;
}
public void incrementCorrect(int ID){
SQLiteDatabase database = this.getWritableDatabase();
String incrementQuery = "UPDATE flashcards SET correct = correct +1 WHERE CardID = '" + ID + "'" ;
database.execSQL(incrementQuery);
}
public void incrementAnswered(int randomID) {
SQLiteDatabase database = this.getWritableDatabase();
String incrementQuery = "UPDATE flashcards SET answered = answered +1 WHERE CardID = '" + randomID + "'" ;
database.execSQL(incrementQuery);
}
public HashMap<String, String> getCardInfo(int randomID){
HashMap<String, String> cardMap = new HashMap<String, String>();
SQLiteDatabase database = this.getReadableDatabase();
String selectQuery = "SELECT * FROM flashcards WHERE cardID ='" + randomID + "'";
Cursor cursor = database.rawQuery(selectQuery, null);
if(cursor.moveToFirst()){
do{
cardMap.put("cardID", cursor.getString(0));
cardMap.put("question", cursor.getString(1));
cardMap.put("answer", cursor.getString(2));
cardMap.put("subject", cursor.getString(3));
cardMap.put("answered", cursor.getString(4));
cardMap.put("correct", cursor.getString(5));
} while(cursor.moveToNext());
}
return cardMap;
}
}
This is the activity code
package com.izulki.flipper;
import java.util.ArrayList;
import java.util.HashMap;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;
public class FlashcardsAnswer extends Activity {
DBTools dbTools = new DBTools(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_flashcards_random);
TextView currentID = (TextView) findViewById(R.id.currentIdText);
ArrayList<HashMap<String, String>> IDList = dbTools.getIDList();
currentID.setText((IDList.get(0)).toString());
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.flashcards_answer, menu);
return true;
}
}
And this is the error
02-21 15:02:55.777: E/AndroidRuntime(1827): FATAL EXCEPTION: main
02-21 15:02:55.777: E/AndroidRuntime(1827): java.lang.RuntimeException: Unable to instantiate application android.app.Application: java.lang.IllegalStateException: Unable to get package info for com.izulki.flipper; is package not installed?
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.LoadedApk.makeApplication(LoadedApk.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.ActivityThread.handleBindApplication(ActivityThread.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.ActivityThread.access$1300(ActivityThread.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.ActivityThread$H.handleMessage(ActivityThread.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.os.Handler.dispatchMessage(Handler.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.os.Looper.loop(Looper.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.ActivityThread.main(ActivityThread.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at java.lang.reflect.Method.invokeNative(Native Method)
02-21 15:02:55.777: E/AndroidRuntime(1827): at java.lang.reflect.Method.invoke(Method.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at dalvik.system.NativeStart.main(Native Method)
02-21 15:02:55.777: E/AndroidRuntime(1827): Caused by: java.lang.IllegalStateException: Unable to get package info for com.izulki.flipper; is package not installed?
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): at android.app.LoadedApk.getClassLoader(LoadedApk.java)
02-21 15:02:55.777: E/AndroidRuntime(1827): ... 12 more
解决方案
Try this :
for (HashMap<String, String> map : IDList)
for (Entry<String, String> mapEntry : map.entrySet())
{
String key = mapEntry.getKey();
String value = mapEntry.getValue();
}
For single Element : IDList.get(0).get(key);
这篇关于安卓：从ArrayList中的Hashmap单获取价值？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！