我的代码出现问题。我正在尝试用搜索开发字典。正在从MySQl数据库中提取数据。在输入单词时，它会崩溃。请帮忙。我一直在尝试进行大量修改，直到我提出要求。有人帮忙吗？
package com.example.healthhelpv2;
import java.sql.Blob;
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 library.JSONParser2;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class ListMedicineActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser2 jParser = new JSONParser2();
//private ArrayList arr_sort= new ArrayList();
private ArrayList arr_sort= new ArrayList();
ArrayList<HashMap<String, String>> patientsList;
ArrayAdapter<String> adapter;
//private ListView lv1;
private EditText et;
int textlength=0;
// url to get all products list
private static String url_all_medicine = "http://10.0.2.2/android_connect/get_all_medicines.php";
private ListView lv;
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_MEDICINE = "medicine";
private static final String TAG_MID = "mid";
private static final String TAG_MED_NAME = "med_name";
// private static final Blob TAG_IMG = "img";
//private static final String TAG_MED_INFO = "med_info";
// products JSONArray
JSONArray patients = null;
//ArrayAdapter adapter;
public void onBackPressed() {
super.onBackPressed();
//userFunctions.logoutUser(getApplicationContext());
Intent intent = new Intent(this, PatientHomeActivity.class);
startActivity(intent);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listmedicine);
// Hashmap for ListView
patientsList = new ArrayList<HashMap<String, String>>();
//arr_sort = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String mid = ((TextView) view.findViewById(R.id.mid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
MedInfoActivity.class);
// sending pid to next activity
in.putExtra(TAG_MID, mid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
//search
lv=(ListView)findViewById(android.R.id.list);
et=(EditText)findViewById(R.id.searchtext);
//lv.setAdapter(new ArrayAdapter(this,android.R.layout.si mple_list_item_1 , patientsList));
ArrayAdapter<String> adapter = new ArrayAdapter(this,R.layout.all_patient , R.id.med_name, patientsList);
lv.setAdapter(adapter);
et.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
// When user changed the Text
ListMedicineActivity.this.adapter.getFilter().filter(cs);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
}
});
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ListMedicineActivity.this);
pDialog.setMessage("Loading medicines. 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>();
//params.add(new BasicNameValuePair("name",""));
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_medicine, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Medicines: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
patients = json.getJSONArray(TAG_MEDICINE);
// looping through All Products
for (int i = 0; i < patients.length(); i++) {
JSONObject c = patients.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_MID);
String name = c.getString(TAG_MED_NAME);
// Blob img = c.getBlob(TAG_IMG);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_MID, id);
map.put(TAG_MED_NAME, name);
// map.put(TAG_IMG, img);
// adding HashList to ArrayList
patientsList.add(map);
//patientsList.add(json.getString("mid").toString());
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} 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
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
ListMedicineActivity.this, patientsList,
R.layout.all_medicine, new String[] { TAG_MID,
TAG_MED_NAME},
new int[] { R.id.mid, R.id.med_name});
// updating listview
setListAdapter(adapter);
}
});
}
}
}
这是错误日志。
01-26 09:30:56.372: E/AndroidRuntime(272): FATAL EXCEPTION: main
01-26 09:30:56.372: E/AndroidRuntime(272): java.lang.NullPointerException
01-26 09:30:56.372: E/AndroidRuntime(272): at com.example.healthhelpv2.ListMedicineActivity$2.onTextChanged(ListMedicineActivity.java:128)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.widget.TextView.sendOnTextChanged(TextView.java:6131)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.widget.TextView.handleTextChanged(TextView.java:6172)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:6316)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.SpannableStringBuilder.sendTextChange(SpannableStringBuilder.java:889)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.SpannableStringBuilder.change(SpannableStringBuilder.java:352)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.SpannableStringBuilder.change(SpannableStringBuilder.java:269)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:432)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:409)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:28)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.method.QwertyKeyListener.onKeyDown(QwertyKeyListener.java:195)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.text.method.TextKeyListener.onKeyDown(TextKeyListener.java:132)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.widget.TextView.doKeyDown(TextView.java:4304)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.widget.TextView.onKeyDown(TextView.java:4149)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.KeyEvent.dispatch(KeyEvent.java:1037)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.View.dispatchKeyEvent(View.java:3740)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:788)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:788)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:788)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:788)
01-26 09:30:56.372: E/AndroidRuntime(272): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1667)
01-26 09:30:56.372: E/AndroidRuntime(272): at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1102)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.app.Activity.dispatchKeyEvent(Activity.java:2063)
01-26 09:30:56.372: E/AndroidRuntime(272): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1643)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewRoot.deliverKeyEventToViewHierarchy(ViewRoot.java:2471)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2441)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.view.ViewRoot.handleMessage(ViewRoot.java:1735)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.os.Handler.dispatchMessage(Handler.java:99)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.os.Looper.loop(Looper.java:123)
01-26 09:30:56.372: E/AndroidRuntime(272): at android.app.ActivityThread.main(ActivityThread.java:4627)
01-26 09:30:56.372: E/AndroidRuntime(272): at java.lang.reflect.Method.invokeNative(Native Method)
01-26 09:30:56.372: E/AndroidRuntime(272): at java.lang.reflect.Method.invoke(Method.java:521)
01-26 09:30:56.372: E/AndroidRuntime(272): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-26 09:30:56.372: E/AndroidRuntime(272): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-26 09:30:56.372: E/AndroidRuntime(272): at dalvik.system.NativeStart.main(Native Method)
这是我的listmedicine.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<!-- Main ListView
Always give id value as list(@android:id/list)
-->
<EditText
android:id="@+id/searchtext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10" >
<requestFocus />
</EditText>
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="#b5b5b5"
android:dividerHeight="1dp"
android:listSelector="@drawable/list_selector" >
</ListView>
</LinearLayout>
和我的all_medicine.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/list_selector"
android:orientation="horizontal"
android:padding="5dip" >
<!-- Product id (pid) - will be HIDDEN - used to pass to other activity -->
<!-- Name Label -->
<TextView
android:id="@+id/med_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#000000"
android:textSize="20dp"
android:textStyle="bold" />
<TextView
android:id="@+id/mid"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:contentDescription="@string/app_name"
android:src="@drawable/arrow" />
</RelativeLayout>
任何人都可以帮我解决我的代码有什么问题吗？希望你能帮助我。
答案 0 :(得分：0)
试试这个。
public void onTextChanged(CharSequence cs, int arg1, int arg2,
int arg3) {
// When user changed the Text
ListMedicineActivity.this.adapter.getFilter().filter(cs);
}
将此适配器提取到类
中 lv1.setAdapter(new ArrayAdapter(this,android.R.layout.simple_list_item_1 , patientsList));
例如
ArrayAdapter<String> adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1 , patientsList);
lv1.setAdapter(adapter);
然后你可以在监听器中使用那个，它应该工作