清除机器人的ListView机器人、ListView
我有一个ListView。我要动态地更改使用的listview.I的内容adapter.notifyDataSetChanged（）;改变的内容。我也曾尝试设置列表视图的适配器为空，但我仍得到相同的结果。这是令人耳目一新，但不清除列表视图，而不是它与previous结果追加吧。我要的是previous内容应该被删除，新的结果应该显示出来。
我无法明白哪里是我的错误，我所缺少的。
我会很感激，如果有人可以请帮我出这一点。
下面是code生成列表视图
公共无效ListDrawer（）{
尝试 {
JSONObject的jsonResponse =新的JSONObject（jsonResult）;
JSONArray jsonMainNode = jsonResponse.optJSONArray（myRegisteredList）;
的for（int i = 0; I＆LT; jsonMainNode.length（）;我++）{
的JSONObject jsonChildNode = jsonMainNode.getJSONObject（ⅰ）;
字符串registered_name = jsonChildNode.optString（研讨会）;
字符串组织= jsonChildNode.optString（组织者）;
字符串sem_id = jsonChildNode.optString（ID）;
串r_sem = jsonChildNode.optString（seminar_id）;
registeredlist =新的HashMap＆LT;字符串，字符串＆GT;（）;
registeredlist.put（registeredList，registered_name）;
registeredlist.put（seminar_id，r_sem）;
registeredlist.put（sem_id，sem_id）;
registeredlist.put（组织者，组织）;
registeredList.add（registeredlist）;
}
}赶上（JSONException E）{
。//Toast.makeText(this，e.getMessage（）的toString（）+1，Toast.LENGTH_LONG）.show（）;
Toast.makeText（ViewReservedSeminarList.this，对不起......你没有任何保留的研讨会/秒，Toast.LENGTH_LONG）.show（）;
}
尝试{
simpleAdapter =新SimpleAdapter（这一点，registeredList，
android.R.layout.simple_list_item_2，
新的String [] {registeredList，组织者，seminar_id}，新的INT [] {android.R.id.text1，android.R.id.text2，android.R.id.title}）;
listView.setAdapter（simpleAdapter）;
listView.setOnItemClickListener（新OnItemClickListener（）{
@覆盖
公共无效onItemClick（适配器视图＆LT;＆gt;一种，视图V，INT I，长L）{
// TODO自动生成方法存根
@燮pressWarnings（未登记）
HashMap的＆LT;字符串，字符串＆GT; selected_row =（＆HashMap中所述;字符串，字符串＆GT）simpleAdapter.getItem（ⅰ）;
S_ID = selected_row.get（seminar_id）;
意向意图=新的意图（ViewReservedSeminarList.this，ReservedSeminar.class）;
startActivity（意向）;
//Toast.makeText(ViewReservedSeminarList.this，选定条目：+ S_ID，Toast.LENGTH_LONG）.show（）;
}
}）;
}赶上（例外五）{
。//Toast.makeText(this，e.getMessage（）的toString（）+2，Toast.LENGTH_LONG）.show（）;
Toast.makeText（ViewReservedSeminarList.this，没有数据被取出，Toast.LENGTH_LONG）.show（）;
}
}
下面是我放置在onCreate方法来刷新列表视图每10秒的片段。我呼吁下accessWebService方法ListDrawer方法。
最后的处理程序处理程序=新的处理程序（）;
handler.postDelayed（新的Runnable（）{
@覆盖
公共无效的run（）{
accessWebService（）;
handler.postDelayed（此，10 * 1000）;
Log.i（TAG，通知）;
}
}，10 * 1000
）;
解决方案
试试这个，请：
清除该ArrayList / HashMap的的
添加新项的
adapter.notifyDataSetChanged（）;
设置适配器。的
I have a ListView. I want to dynamically change the contents of the listview.I used "adapter.notifyDataSetChanged();" to change the contents. I have also tried setting the adapter of the listview to null but still I get the same results. It is refreshing but not clearing the listview, instead it is appending it with the previous results. What i want is the previous contents should be deleted and the new results should be displayed.
I am not able to understand where is my mistake and what i am missing.
I would be Thankful if someone could please help me out with this.
Below is the code that generates the listview
public void ListDrawer() {
try {
JSONObject jsonResponse = new JSONObject(jsonResult);
JSONArray jsonMainNode = jsonResponse.optJSONArray("myRegisteredList");
for (int i = 0; i < jsonMainNode.length(); i++) {
JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
String registered_name = jsonChildNode.optString("seminar");
String org = jsonChildNode.optString("organizer");
String sem_id = jsonChildNode.optString("id");
String r_sem = jsonChildNode.optString("seminar_id");
registeredlist = new HashMap<String, String>();
registeredlist.put("registeredList", registered_name);
registeredlist.put("seminar_id", r_sem);
registeredlist.put("sem_id", sem_id);
registeredlist.put("organizer", org);
registeredList.add(registeredlist);
}
} catch (JSONException e) {
//Toast.makeText(this, e.getMessage().toString() + " 1", Toast.LENGTH_LONG).show();
Toast.makeText(ViewReservedSeminarList.this, "Sorry...You don't have any reserved seminar/s.", Toast.LENGTH_LONG).show();
}
try{
simpleAdapter = new SimpleAdapter(this, registeredList,
android.R.layout.simple_list_item_2,
new String[] { "registeredList" ,"organizer", "seminar_id" }, new int[] { android.R.id.text1 , android.R.id.text2 , android.R.id.title });
listView.setAdapter(simpleAdapter);
listView.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> a, View v, int i, long l) {
// TODO Auto-generated method stub
@SuppressWarnings("unchecked")
HashMap<String, String> selected_row = (HashMap<String, String>) simpleAdapter.getItem(i);
s_id = selected_row.get("seminar_id");
Intent intent = new Intent(ViewReservedSeminarList.this, ReservedSeminar.class);
startActivity(intent);
//Toast.makeText(ViewReservedSeminarList.this, "Selected Item : "+s_id, Toast.LENGTH_LONG).show();
}
});
}catch(Exception e){
//Toast.makeText(this, e.getMessage().toString() + " 2", Toast.LENGTH_LONG).show();
Toast.makeText(ViewReservedSeminarList.this, "There is no data being fetched", Toast.LENGTH_LONG).show();
}
}
Below is the snippet I placed on the onCreate method to refresh the listview every 10 seconds. I am calling the ListDrawer method under the accessWebService method.
final Handler handler = new Handler();
handler.postDelayed( new Runnable(){
@Override
public void run(){
accessWebService();
handler.postDelayed(this, 10 * 1000);
Log.i("TAG", "notify");
}
}, 10 * 1000
);
解决方案
Try this please:
Clear the arraylist/HashMap
Add new items
adapter.notifyDataSetChanged();
set adapter.
