ListView仅显示ArrayList的最后一个元素（HashMap） [英] ListView displaying only the final element of a ArrayList(HashMap)
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问题描述
我有一个活动类，通过查询获取JSON字符串。我把这个字符串解析成一个ArrayList（HashMap（String，String））。我传递给ListView。我面临的问题是显示ArrayList的元素时，只有列表中的最后一个元素显示在UI中。即如果列表中有三个元素，则第三个元素显示三次
这是我的函数。 buglist视图中有一个ListView，而R.id.text1 / 2/3基本上是TextViews。
public class GetBugs扩展ListActivity {
public static final String BASE_URL =http://172.19.194.89:3000;
public static String response_string =default message;
private static ArrayList< HashMap< String，String>> buglist;
/ **当活动首次创建时调用。 * /
@Override
public void onCreate（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）;
buglist = new ArrayList< HashMap< String，String>>（）;
setContentView（R.layout.bugslist）;
}
@Override
public void onStart（）{
super.onStart（）;
//发送一个HTTP GET请求来获取bug详细信息
String bugs = RestClient.getData（http://172.19.194.89:3000/bug）;
// String count = RestClient.getData（http://172.19.194.89:3000/count）;
Log.i（DEBUG，BUGS LIST：+ bugs）;
parseBugs（bugs）;
ListAdapter adapter = new SimpleAdapter（this，buglist，R.layout.bugrow，
new String [] {summary，platform，product}，
new int [] {R.id.text1，R.id.text2，R.id.text3}）;
setListAdapter（adapter）;
$ public void parseBugs（String bugstring）{
try {
JSONObject jobject = new JSONObject（bugstring）;
JSONArray bugdetails = jobject.getJSONArray（bugs）;
int i = 0;
HashMap< String，String> item = new HashMap< String，String>（）;
String item_val;
JSONObject e = new JSONObject（）;
while（i< bugdetails.length（））{
e = bugdetails.getJSONObject（i）;
item_val = e.getString（summary）;
item.put（summary，item_val）;
item_val = e.getString（platform）;
item.put（platform，item_val）;
item_val = e.getString（product）;
item.put（product，item_val）;
buglist.add（i，item）;
i ++;
}
Log.i（INFO，HashMap Array is populated）;
catch（JSONException e）{
// TODO自动生成的catch块
e.printStackTrace（）;
}
}
如果需要，我也可以提供视图。当我调试代码时，我能够看到bugslist变量设置正确，所以我假设问题可能与它在视图中访问变量的方式有关。
这些是视图
1.bugslist.xml
<？xml version =1.0encoding =utf-8？>
< LinearLayout xmlns：android =http://schemas.android.com/apk/res/android
android：orientation =vertical
android：layout_width =fill_parent
android：layout_height =fill_parent>
ListView
android：id =@ id / android：list
android：layout_width =fill_parent
android：layout_height =fill_parent
android：layout_weight =2
android：drawSelectorOnTop =false>
< / ListView>
< TextView android：id =@ id / android：empty
android：layout_width =fill_parent
android：layout_height =fill_parent
android：text =没有数据>
< / TextView>
< / LinearLayout>
2.bugrow.xml
<？xml version =1.0encoding =utf-8？>
< LinearLayout xmlns：android =http://schemas.android.com/apk/res/android
android：orientation =vertical
android：layout_width =fill_parent
android：layout_height =fill_parent>
TextView
android：id =@ + id / text1
android：textSize =16sp
android：textStyle =bold
android：layout_width =fill_parent
android：layout_height =fill_parent>
< / TextView>
TextView android：id =@ + id / text2
android：textSize =12sp
android：textStyle =bold
android： layout_width =wrap_content
android：layout_height =fill_parent>
< / TextView>
TextView android：id =@ + id / text3
android：typeface =sans
android：textSize =14sp
android： textStyle =italic
android：layout_width =wrap_content
android：layout_height =wrap_content>
< / TextView>
< / LinearLayout>
感谢
Sreenath
解决方案
因为你三次添加同一个对象。
你应该创建一个新的hashmap实例。
public void parseBugs（String bugstring）{
尝试{
JSONObject jobject = new JSONObject（bugstring）;
JSONArray bugdetails = jobject.getJSONArray（bugs）;
int i = 0;
String item_val;
JSONObject e = new JSONObject（）;
while（i< bugdetails.length（））{
HashMap< String，String> item = new HashMap< String，String>（）;
e = bugdetails.getJSONObject（i）;
item_val = e.getString（summary）;
item.put（summary，item_val）;
item_val = e.getString（platform）;
item.put（platform，item_val）;
item_val = e.getString（product）;
item.put（product，item_val）;
buglist.add（i，item）;
i ++;
}
Log.i（INFO，HashMap Array is populated）;
catch（JSONException e）{
// TODO自动生成的catch块
e.printStackTrace（）;
}
I have an activity class that gets a JSON string by making a query. I parsed the string into a ArrayList(HashMap(String, String)). I am passing this to a ListView. The problem I am facing is while displaying the elements of the ArrayList only the last element in the list is shown in the UI. i.e. if there are 3 elements in the list, the third element is shown thrice
This is my Function. The "buglist" view has a ListView in it and R.id.text1/2/3 are basically TextViews.
public class GetBugs extends ListActivity {
public static final String BASE_URL = "http://172.19.194.89:3000";
public static String response_string="default message";
private static ArrayList<HashMap<String,String>> buglist;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
buglist = new ArrayList<HashMap<String,String>>();
setContentView(R.layout.bugslist);
}
@Override
public void onStart(){
super.onStart();
// Send a HTTP GET Request to get bug details
String bugs=RestClient.getData("http://172.19.194.89:3000/bug");
//String count=RestClient.getData("http://172.19.194.89:3000/count");
Log.i("DEBUG","BUGS LIST:"+bugs);
parseBugs(bugs);
ListAdapter adapter = new SimpleAdapter(this, buglist, R.layout.bugrow,
new String[] {"summary","platform","product"},
new int[] {R.id.text1,R.id.text2, R.id.text3});
setListAdapter(adapter);
}
public void parseBugs(String bugstring){
try {
JSONObject jobject = new JSONObject(bugstring);
JSONArray bugdetails = jobject.getJSONArray("bugs");
int i=0;
HashMap<String, String> item = new HashMap<String, String>();
String item_val;
JSONObject e = new JSONObject();
while(i<bugdetails.length()){
e=bugdetails.getJSONObject(i);
item_val = e.getString("summary");
item.put("summary", item_val);
item_val = e.getString("platform");
item.put("platform", item_val);
item_val = e.getString("product");
item.put("product", item_val);
buglist.add(i, item);
i++;
}
Log.i("INFO", "The HashMap Array is populated");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
I can provide the views also if needed. When i debug the code, I was able to see that the bugslist variable is set correctly, so i assume the problem might be with the way its accessing the variable in the view.
These are the views
1.bugslist.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:id="@id/android:list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="2"
android:drawSelectorOnTop="false">
</ListView>
<TextView android:id="@id/android:empty"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="No data">
</TextView>
</LinearLayout>
2.bugrow.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/text1"
android:textSize="16sp"
android:textStyle="bold"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
</TextView>
<TextView android:id="@+id/text2"
android:textSize="12sp"
android:textStyle="bold"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
</TextView>
<TextView android:id="@+id/text3"
android:typeface="sans"
android:textSize="14sp"
android:textStyle="italic"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</TextView>
</LinearLayout>
Thanks Sreenath
解决方案
Because you add the same object three times. you should create a new hashmap instance very time.
public void parseBugs(String bugstring){
try {
JSONObject jobject = new JSONObject(bugstring);
JSONArray bugdetails = jobject.getJSONArray("bugs");
int i=0;
String item_val;
JSONObject e = new JSONObject();
while(i<bugdetails.length()){
HashMap<String, String> item = new HashMap<String, String>();
e=bugdetails.getJSONObject(i);
item_val = e.getString("summary");
item.put("summary", item_val);
item_val = e.getString("platform");
item.put("platform", item_val);
item_val = e.getString("product");
item.put("product", item_val);
buglist.add(i, item);
i++;
}
Log.i("INFO", "The HashMap Array is populated");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
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