我在android中创建了一个具有Swipe布局的活动。它在滑动时使用片段用于不同的选项卡。 现在我想在每个Tabs / Fragments中放置一个不同的微调器。 微调器的数据是从mysql服务器加载的。数据加载并放置在微调器中。但现在我不知道如何将旋转器放在一个片段中。 当我将微调器放在一个空白活动中但我不知道将它放在片段代码中的位置时，它可以工作。
package com.example.vanhulzenapp;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Locale;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.NavUtils;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;
public class DisplayProductList extends FragmentActivity implements
ActionBar.TabListener {
TextView text_1,text_2 ;
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_product_list);
new task().execute();
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Show the Up button in the action bar.
actionBar.setDisplayHomeAsUpEnabled(true);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
class task extends AsyncTask<String,Integer,Void>
{
private ProgressDialog progressDialog = new ProgressDialog(DisplayProductList.this);
InputStream is = null ;
String result = "";
protected void onPreExecute() {
progressDialog.setMessage("Download data...");
progressDialog.show();
progressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
public void onCancel(DialogInterface arg0) {
task.this.cancel(true);
}
});
}
@Override
protected Void doInBackground(String... params) {
String url_select = "http://192.168.2.2/select.php";
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url_select);
ArrayList param = new ArrayList();
try {
httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
//read content
is = httpEntity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection "+e.toString());
}
try {
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = "";
while((line=br.readLine())!=null)
{
sb.append(line+"\n");
}
is.close();
result=sb.toString();
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error converting result "
+e.toString());
}
return null;
}
protected void onPostExecute(Void v) {
// ambil data dari Json database
try {
JSONArray Jarray = new JSONArray(result);
ArrayAdapter<CharSequence> adapter = new ArrayAdapter<CharSequence>
(DisplayProductList.this, android.R.layout.simple_spinner_item );
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
for(int i=0;i<Jarray.length();i++)
{
Log.i("log_tag", "Jarray length - " + Jarray.length());
Log.i("log_tag", "Jarray Object - " + Jarray.getJSONObject(i));
JSONObject Jasonobject = null;
text_1 = (TextView)findViewById(R.id.txt1);
Jasonobject = Jarray.getJSONObject(i);
adapter.add(Jasonobject.getString("ProductName"));
Log.i("log_tag", "adapter Item - " + adapter.getItem(i));
}
Spinner s = (Spinner) findViewById(R.id.ddName);
s.setAdapter(adapter);
this.progressDialog.dismiss();
} catch (Exception e) {
Log.e("log_tag", "Error parsing data "+e.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.display_product_list, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
**/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(
R.layout.fragment_display_product_list_dummy, container,
false);
/*
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER))); */
return rootView;
}
}
}
我认为这是它应该发生的部分：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(
R.layout.fragment_display_product_list_dummy, container,
false);
/*
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER))); */
return rootView;
}
但我不确定如何将其与onPostExecute中发生的结果相关联，其中数据放在微调器中。
Spinner s = (Spinner) findViewById(R.id.ddName);
s.setAdapter(adapter);
我真的希望有人可以帮助我，因为我真的被这个困住了。
Tnx提前很多
答案 0 :(得分：2)
你需要在每个片段的onCreateView（）方法中创建微调器是正确的。因此，您需要确保在三个布局文件中为片段定义了三个微调器。
现在，关于从AsyncTask获取数据..我最终可能会做的是在三个片段中的每个片段中调用异步任务。这样，您就可以编写特定于片段所需内容的每个任务。这样做可以让您轻松地将数据添加到微调器。
因此，您首先要让整个班级都可以访问您的微调器：
Spinner mSpinner;
然后，在onCreateView（）中：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(
R.layout.fragment_display_product_list_dummy, container,
false);
mSpinner = (Spinner) rootView.findViewById(R.id.frag1spinner);
}
最后，在片段的onPostExecute（）中，分配适配器：
mSpinner.setAdapter(adapter);
我或多或少会这样做。任何人请让我知道这个的好坏;）
答案 1 :(得分：0)
对我来说，我认为您应该将微调器或适配器的引用保持为顶级成员，然后在片段onCreateView中，您可以设置适配器并填充它。在onPostExecute中更改数据后，您是否可以在适配器上调用notifyDataSetChanged？