当我运行此代码时，我在listview中没有得到任何内容。
我试图在文本视图中从服务器获取值，我从有效负载对象中的服务器获取值。但是我的列表视图仍然没有显示任何内容，并且logcat中没有错误。
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.zalonstyles.app.zalon.Model.Services;
import com.zalonstyles.app.zalon.Model.ViewHolder;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
这是我从服务器
获取数据的类public class popup_massage extends AppCompatActivity {
public static final String URL = "http://52.41.72.46:8080/service/get_category";
public final String serviceid = "6";
private ListView mainListView;
private Button check;
private List<Services> massagelist = new ArrayList<>();
private Services massageservice[];
private Context context;
public ArrayAdapter<Services> listAdapter;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.popup_massage);
SharedPreferences mSharedPreference= PreferenceManager.getDefaultSharedPreferences(getBaseContext());
String value=(mSharedPreference.getString("AppConstant.AUTH_TOKEN", "DEFAULT"));
Log.e("accesslog",value);
mainListView = (ListView) findViewById(R.id.listView4);
check = (Button) findViewById(R.id.button4);
final JSONObject params = new JSONObject();
try {
params.put("service_id",serviceid);
} catch (JSONException e) {
e.printStackTrace();
}
try {
params.put("access_token", value);
} catch (JSONException e) {
e.printStackTrace();
}
StringRequest stringRequest = new StringRequest(Request.Method.POST, URL,
new Response.Listener<String>(){
@Override
public void onResponse(String response) {
Log.v("updateUPVolleyRes1",response);
try {
JSONObject jobject = new JSONObject(response);
JSONArray payload = jobject.getJSONArray("payload");
Log.e("payloaddata", String.valueOf(payload));
for (int i = 0; i < payload.length(); i++) {
try{
JSONObject obj = payload.getJSONObject(i);
Services service = new Services();
service.setName(obj.getString("name"));
service.setcategotry_id(obj.getString("id"));
massagelist.add(service);
}finally {
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.v("updateUPVolleyErr", error.toString());
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params1 = new HashMap<String, String>();
params1.put("payload", params.toString());
Log.v("updateUPVolleyParams", params1.toString());
return params1;
}
};
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
mainListView
.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View item,
int position, long id)
{
Services massageservice = listAdapter.getItem(position);
Log.e("CHECKADAPTOR", String.valueOf(massageservice));
massageservice.toggleChecked();
ViewHolder viewHolder =(ViewHolder) item
.getTag();
viewHolder.getCheckBox().setChecked(massageservice.isChecked());
}
});
//Services[] massageService = (Services[]) getLastNonConfigurationInstance();ArrayList<Services> massagelist = new ArrayList<Services>();
//massagelist.addAll(Arrays.asList(massageService));
// Set our custom array adapter as the ListView's adapter.
listAdapter = new massageArrayAdapter(this,massagelist);
mainListView.setAdapter(listAdapter);
check.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
for (int i = 0; i < listAdapter.getCount(); i++)
{
Services massage = listAdapter.getItem(i);
if (massage.isChecked())
{
Toast.makeText(getApplicationContext(),
massage.getName() + " is Checked!!",
Toast.LENGTH_SHORT).show();
Log.v("My Custom Tag", massage.getName());
}
}
}
});
}
//arrayadapter class//
private static class massageArrayAdapter extends ArrayAdapter<Services>
{
private LayoutInflater inflater;
public massageArrayAdapter(Context context, List<Services> massagelist)
{
super(context, R.layout.customlist_massage, R.id.massagetextview, massagelist);
// Cache the LayoutInflate to avoid asking for a new one each time.
inflater = LayoutInflater.from((Context) context);
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
// services to display
Services massage = (Services) this.getItem(position);
// The child views in each row.
CheckBox checkBox;
TextView textView;
// Create a new row view
if (convertView == null)
{
convertView = inflater.inflate(R.layout.customlist_massage,null );
// Find the child views.
textView = (TextView) convertView
.findViewById(R.id.massagetextview);
checkBox = (CheckBox) `enter code here`convertView.findViewById(R.id.checkBox4);
// Optimization: Tag the row with it's child views, so we don't
// have to
// call findViewById() later when we reuse the row.
convertView.setTag(new ViewHolder(textView, checkBox));
// If CheckBox is toggled, update the planet it is tagged with.
checkBox.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
CheckBox cb = (CheckBox) v;
Services massage = (Services) cb.getTag();
massage.setChecked(cb.isChecked());
}
});
}
// Reuse existing row view
else
{
// Because we use a ViewHolder, we avoid having to call
// findViewById().
ViewHolder viewHolder = (ViewHolder) convertView
.getTag();
checkBox = viewHolder.getCheckBox();
textView = viewHolder.getTextView();
}
// Tag the CheckBox with the service it is displaying,
// access the planet in onClick() when the CheckBox is toggled.
checkBox.setTag(massage);
// Display planet data
checkBox.setChecked(massage.isChecked());
textView.setText(massage.getName());
return convertView;
}
}
}
我的服务类用于存储服务
public class Services
{
private String name = "";
private boolean checked = false;
private String categotry_id="";
public Services()
{
}
public Services(String name)
{
this.name = name;
}
public Services(String name, boolean checked,String categotry_id)
{
this.name = name;
this.categotry_id = categotry_id;
this.checked = checked;
}
public Services(String name,String categotry_id)
{
this.name = name;
this.categotry_id = categotry_id;
}
public String getCategory_id(String id)
{
return categotry_id;
}
public void setcategotry_id(String categotry_id)
{
this.name = categotry_id;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public boolean isChecked()
{
return checked;
}
public void setChecked(boolean checked)
{
this.checked = checked;
}
public String toString()
{
return name;
}
public void toggleChecked()
{
checked = !checked;
}
}
查看用于存储视图的持有者类
public class ViewHolder
{
private CheckBox checkBox;
private TextView textView;
public ViewHolder()
{
}
public ViewHolder(TextView textView, CheckBox checkBox)
{
this.checkBox = checkBox;
this.textView = textView;
}
public CheckBox getCheckBox()
{
return checkBox;
}
public void setCheckBox(CheckBox checkBox)
{
this.checkBox = checkBox;
}
public TextView getTextView()
{
return textView;
}
public void setTextView(TextView textView)
{
this.textView = textView;
}
}
我的xml类列表视图在哪里
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#3F51B5">
<ListView
android:id="@+id/listView4"
android:layout_width="match_parent"
android:layout_height="0px"
android:background="#fff"
android:layout_weight="1" >
</ListView>
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginLeft="313dp"
android:text="Continue" />
</LinearLayout>
请帮我解决这个问题，我需要在明天之前提交。
答案 0 :(得分：0)
使用此
convertView = inflater.inflate(R.layout.customlist_massage,null ,false );
而不是这个
convertView = inflater.inflate(R.layout.customlist_massage,null );
答案 1 :(得分：0)
为什么要扩展适配器类ArrayAdapter。 如果您想在listview上显示某些内容，则必须将其扩展到BaseAdapter或Recyclerview适配器。 您在ArrayAdapter中没有任何getCount（）方法，请参阅此示例::
public class Adapter extends BaseAdapter {
LayoutInflater li;
ArrayList<String> title, details;
Context con;
DataBaseHelper db;
TextView txttitle, txtdetails, txtDate;
Intent in;
public static int i = 1;
View view;
public Adapter (Context cont, ArrayList<String> news_id, ArrayList<String> news) {
this.title = news_id;
this.details = news;
this.con = cont;
li = (LayoutInflater) con.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
System.out.println("title.size() " + title.size());
return title.size();
}
@Override
public Object getItem(int arg0) {
return arg0;
}
@Override
public long getItemId(int arg0) {
return arg0;
}
@Override
public View getView(int arg0, View arg1, ViewGroup arg2) {
if (arg1 == null) {
arg1 = li.inflate(R.layout.adapter_daycare, null);
txttitle = (TextView) arg1.findViewById(R.id.title);
txtdetails = (TextView) arg1.findViewById(R.id.details);
txtDate = (TextView) arg1.findViewById(R.id.txtdate);
view = (View) arg1.findViewById(R.id.view);
}
String date = new SimpleDateFormat("dd/MM/yyyy").format(new Date());
System.out.println(" formattedDate " + date);
txttitle.setText(title.get(arg0).toString());
txtdetails.setText(details.get(arg0).toString());
txtDate.setText(date);
return arg1;
}
}