我想从列表视图中获取值。列表视图是由HashMap的类型的数组列表中设置。所以,如果我想获得一个字符串中,我得到了错误的值的HashMap不能转换为java.lang.String
details1.java
包com.example.festipedia_logo;进口的java.util.ArrayList;进口的java.util.HashMap;进口的java.util.List;进口org.apache.http.NameValuePair;进口org.apache.http.message.BasicNameValuePair;进口org.json.JSONArray;进口org.json.JSONException;进口org.json.JSONObject;进口com.actionbarsherlock.app.SherlockFragment;进口com.actionbarsherlock.app.SherlockListFragment;//进口com.example.festipedia_logo.Searchpage.LoadAllProducts;//进口com.example.connection.disp;进口android.app.Activity;进口android.app.Fragment;进口android.app.ListActivity;进口android.app.ProgressDialog;进口android.content.Intent;进口android.os.AsyncTask;进口android.os.Bundle;进口android.support.v4.app.FragmentTransaction;进口android.util.Log;进口android.view.LayoutInflater;进口android.view.View;进口android.view.ViewGroup;进口android.widget.AdapterView;进口android.widget.AdapterView.OnItemClickListener;进口android.widget.ArrayAdapter;进口android.widget.Button;进口android.widget.EditText;进口android.widget.ListAdapter;进口android.widget.ListView;进口android.widget.SimpleAdapter;进口android.widget.Spinner;进口android.widget.TextView;进口android.widget.Toast;公共类扩展详情1 {SherlockFragment ArrayAdapter<串GT;适配器; 的String []城市; //进度对话框 私人ProgressDialog pDialog; //创建JSON解析器对象 JSONParser jParser =新JSONParser();的EditText B: ArrayList的<&HashMap的LT;字符串,字符串>>产品列表; // URL获得所有产品清单 私人静态字符串url_all_products =http://192.168.43.77/festipedia/get_all_products.php;按钮; // JSON节点名称 私有静态最后弦乐TAG_SUCCESS =成功; 私有静态最后弦乐TAG_PRODUCTS =产品; 私有静态最后弦乐TAG_NAME =eventname已; //产品JSONArray JSONArray产品= NULL;ListView控件升;微调微调; @覆盖 公共查看onCreateView(LayoutInflater充气器,容器的ViewGroup, 捆绑savedInstanceState){ super.onCreate(savedInstanceState); //setContentView(R.layout.second); 查看rootView = inflater.inflate(R.layout.home2,集装箱,FALSE); //的setContentView(R.layout.all_products); L =(ListView控件)rootView.findViewById(R.id.list); //为哈希映射的ListView 产品列表=新的ArrayList<&HashMap的LT;字符串,字符串>>(); 新LoadAllProducts()执行(); l.setOnItemClickListener(新OnItemClickListener(){ @覆盖 公共无效onItemClick(适配器视图<>母公司,观景, INT位置,长的id){ // 做一点事 //字符串itemValue =(字符串)l.getItemAtPosition(位置); //意向意图=新意图(getActivity()。getBaseContext() // MainActivity.class); // intent.putExtra(信息,itemValue); // getActivity()startActivity(意向)。 //捆绑ARGS =新包(); // args.putString(doctor_id,itemValue); //点评详情newFragment =新点评详情(); // newFragment.setArguments(参数); //字符串str =((的TextView)childView).getText()的toString()。 // MainActivity OB =新MainActivity(); // ListView中单击项目指标 INT itemPosition =位置; // ListView中单击项目价值 字符串itemValue =(字符串)l.getItemAtPosition(位置); 最后FragmentTransaction英尺= getFragmentManager()调用BeginTransaction()。 ft.replace(R.id.content_frame,新SlidetabTesting(itemValue),巨星内容); ft.commit(); } }); 返回rootView; } / ** *背景异步任务以通过HTTP请求负载的所有产品 * * / 类LoadAllProducts扩展的AsyncTask<字符串,字符串,字符串> { @覆盖 在preExecute保护无效(){ super.on preExecute(); pDialog =新ProgressDialog(getActivity()); pDialog.setMessage(加载产品请稍候......); pDialog.setIndeterminate(假); pDialog.setCancelable(假); pDialog.show(); } / ** *让所有的产品网址 * * / 保护字符串doInBackground(字符串参数... args){ //大厦参数 清单<&的NameValuePair GT; PARAMS =新的ArrayList<&的NameValuePair GT;(); // URL从获取JSON字符串 JSONObject的JSON = jParser.makeHtt prequest(url_all_products,GET,则params); // Log.d(所有产品,json.toString()); 尝试{ //检查成功TAG INT成功= json.getInt(TAG_SUCCESS); 如果(成功== 1){ 发现//产品 //获取产品阵列 产品= json.getJSONArray(TAG_PRODUCTS); //产品通过所有循环 的for(int i = 0; I< products.length();我++){ JSONObject的C = products.getJSONObject(I) //存储在变量中的每个JSON项目 字符串名称= c.getString(TAG_NAME); //l.setFilterText(id); //创建新的HashMap HashMap的<字符串,字符串>地图=新的HashMap<字符串,字符串>(); //将每个子节点的HashMap键=>值 map.put(TAG_NAME,名); //添加HashList到ArrayList的 productsList.add(地图); } }其他{ //没有发现产品 //启动添加新产品活动 } }赶上(JSONException E){ e.printStackTrace(); } 返回null; } / ** *在完成后台任务之后辞退进度对话框 * ** / 保护无效onPostExecute(字符串FILE_URL){ //让所有的产品后,关闭该对话框 pDialog.dismiss(); //从后台线程更新界面 getActivity()。runOnUiThread(新的Runnable(){ 公共无效的run(){ / ** *更新解析JSON数据到ListView控件 * * / ListAdapter适配器=新SimpleAdapter( getActivity(),产品列表, R.layout.list_item,新的String [] { TAG_NAME}, 新的INT [] {R.id.name}); //更新列表视图 l.setAdapter(适配器); } }); } }}
logcat的
20 03-30:03:43.341:E / ViewRootImpl(8395):sendUserActionEvent()== MView的空03-30 20:03:47.111:E / ViewRootImpl(8395):sendUserActionEvent()== MView的空03-30 20:03:49.416:E / AndroidRuntime(8395):致命异常:主要03-30 20:03:49.416:E / AndroidRuntime(8395):工艺:com.example.festipedia_logo,PID:839503-30 20:03:49.416:E / AndroidRuntime(8395):java.lang.ClassCastException:java.util.HashMap中不能转换为java.lang.String03-30 20:03:49.416:E / AndroidRuntime(8395):在com.example.festipedia_logo.details1 $ 1.onItemClick(details1.java:103)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.widget.AdapterView.performItemClick(AdapterView.java:308)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.widget.AbsListView.performItemClick(AbsListView.java:1483)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.widget.AbsListView $ PerformClick.run(AbsListView.java:3485)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.widget.AbsListView $ 3.run(AbsListView.java:4843)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.os.Handler.handleCallback(Handler.java:733)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.os.Handler.dispatchMessage(Handler.java:95)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.os.Looper.loop(Looper.java:157)03-30 20:03:49.416:E / AndroidRuntime(8395):在android.app.ActivityThread.main(ActivityThread.java:5356)03-30 20:03:49.416:E / AndroidRuntime(8395):在java.lang.reflect.Method.invokeNative(本机方法)03-30 20:03:49.416:E / AndroidRuntime(8395):在java.lang.reflect.Method.invoke(Method.java:515)03-30 20:03:49.416:E / AndroidRuntime(8395):在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:1265)03-30 20:03:49.416:E / AndroidRuntime(8395):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)03-30 20:03:49.416:E / AndroidRuntime(8395):在dalvik.system.NativeStart.main(本机方法)
有什么办法由我就能检索值
解决方案java.lang.ClassCastException:java.util.HashMap中不能被转换为 java.lang.String中
这行是问题
字符串itemValue =(字符串)l.getItemAtPosition(位置);
更改为
l.setOnItemClickListener(新OnItemClickListener(){@覆盖公共无效onItemClick(适配器视图<>母公司,观景,INT位置,长的id){HashMap的<字符串,字符串>地图=(HashMap的<字符串,字符串>)l.getItemAtPosition(位置);字符串值= map.get(TAG_SUCCESS);斯汀产品= map.get(TAG_PRODUCTS);字符串名称= map.get(TAG_NAME);... //在code休息}
I am trying to get values from a list view. The list view is set by an array list of hashmap type. So , if I am trying to get the values in a string I get the error HashMap cannot be cast to java.lang.string
details1.java
package com.example.festipedia_logo;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.actionbarsherlock.app.SherlockFragment;
import com.actionbarsherlock.app.SherlockListFragment;
//import com.example.festipedia_logo.Searchpage.LoadAllProducts;
//import com.example.connection.disp;
import android.app.Activity;
import android.app.Fragment;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
public class details1 extends SherlockFragment {
ArrayAdapter<String> adapter;
String[] city;
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
EditText b;
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
private static String url_all_products = "http://192.168.43.77/festipedia/get_all_products.php";
Button a;
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_NAME = "eventname";
// products JSONArray
JSONArray products = null;
ListView l;
Spinner spinner;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.second);
View rootView = inflater.inflate(R.layout.home2, container, false);
// setContentView(R.layout.all_products);
l = (ListView) rootView.findViewById(R.id.list);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
new LoadAllProducts().execute();
l.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Do something
// String itemValue = (String) l.getItemAtPosition(position);
// Intent intent = new Intent(getActivity().getBaseContext(),
// MainActivity.class);
// intent.putExtra("message", itemValue);
// getActivity().startActivity(intent);
// Bundle args = new Bundle();
// args.putString("doctor_id",itemValue);
// details1 newFragment = new details1 ();
// newFragment.setArguments(args);
//String str = ((TextView)childView).getText().toString();
//MainActivity ob=new MainActivity();
// ListView Clicked item index
int itemPosition = position;
// ListView Clicked item value
String itemValue = (String) l.getItemAtPosition(position);
final FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.content_frame,new SlidetabTesting(itemValue) , "Fest Content");
ft.commit();
}
});
return rootView;
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String name = c.getString(TAG_NAME);
//l.setFilterText(id);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_NAME, name);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
getActivity().runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
getActivity(), productsList,
R.layout.list_item, new String[] {
TAG_NAME},
new int[] { R.id.name });
// updating listview
l.setAdapter(adapter);
}
});
}
}
}
LOGCAT
03-30 20:03:43.341: E/ViewRootImpl(8395): sendUserActionEvent() mView == null
03-30 20:03:47.111: E/ViewRootImpl(8395): sendUserActionEvent() mView == null
03-30 20:03:49.416: E/AndroidRuntime(8395): FATAL EXCEPTION: main
03-30 20:03:49.416: E/AndroidRuntime(8395): Process: com.example.festipedia_logo, PID: 8395
03-30 20:03:49.416: E/AndroidRuntime(8395): java.lang.ClassCastException: java.util.HashMap cannot be cast to java.lang.String
03-30 20:03:49.416: E/AndroidRuntime(8395): at com.example.festipedia_logo.details1$1.onItemClick(details1.java:103)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.widget.AdapterView.performItemClick(AdapterView.java:308)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.widget.AbsListView.performItemClick(AbsListView.java:1483)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.widget.AbsListView$PerformClick.run(AbsListView.java:3485)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.widget.AbsListView$3.run(AbsListView.java:4843)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.os.Handler.handleCallback(Handler.java:733)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.os.Handler.dispatchMessage(Handler.java:95)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.os.Looper.loop(Looper.java:157)
03-30 20:03:49.416: E/AndroidRuntime(8395): at android.app.ActivityThread.main(ActivityThread.java:5356)
03-30 20:03:49.416: E/AndroidRuntime(8395): at java.lang.reflect.Method.invokeNative(Native Method)
03-30 20:03:49.416: E/AndroidRuntime(8395): at java.lang.reflect.Method.invoke(Method.java:515)
03-30 20:03:49.416: E/AndroidRuntime(8395): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
03-30 20:03:49.416: E/AndroidRuntime(8395): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
03-30 20:03:49.416: E/AndroidRuntime(8395): at dalvik.system.NativeStart.main(Native Method)
Is there any way by which I will be able to retrieve values
解决方案java.lang.ClassCastException: java.util.HashMap cannot be cast to java.lang.String
This line is the problem
String itemValue = (String) l.getItemAtPosition(position);
Change to
l.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
HashMap<String,String> map =(HashMap<String,String>)l.getItemAtPosition(position);
String value = map.get(TAG_SUCCESS);
Sting products = map.get(TAG_PRODUCTS);
String name= map.get(TAG_NAME);
... // rest of the code
}