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搜索過濾器null例外

2013-12-09 34 views
1

每個listview列包含5textview -ID，Initial，Date，Location，Ward。搜索過濾器null例外

我想讓它通過初始過濾listview。但是，我面臨的第166行的空例外。

我假設editText不是通過初始過濾，它似乎每次我調用適配器將導致錯誤消息。因此，我認爲問題在於適配器。

package com.example.medilearner; 

import java.util.ArrayList; 
import java.util.HashMap; 

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.text.Editable; 
import android.text.TextWatcher; 
import android.util.Log; 
import android.view.Menu; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.EditText; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 
import android.widget.Toast; 

import com.medilearner.database.patientDbAdapter; 

public class PatientDetails extends Activity { 

    // Database adapter 
    patientDbAdapter patientDB; 
    Context myContext; 
    // ArrayAdapter 
    ArrayAdapter<String> adapter; 

    ArrayList<HashMap<String, String>> encouterlist = new ArrayList<HashMap<String, String>>(); 
    // Various layout 
    ListView patientList; 

    static String value; 
    private EditText filterText = null; 

    private static final String TAG_E_ID = "e_id"; 
    private static final String TAG_E_INITIAL = "entry_initial"; 
    private static final String TAG_E_DATE = "entry_date"; 
    private static final String TAG_E_SITELOCATION = "entry_sitelocation"; 
    private static final String TAG_E_WARDCLINIC = "entry_clinic"; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_patient_details); 
     encouterlist = new ArrayList<HashMap<String, String>>(); 
     myContext = this; 
     patientDB = new patientDbAdapter(myContext); 
     patientDB.open(); 
     Cursor mCursor = patientDB.retrieveAllPatientEntriesCursor(); 
     int count = mCursor.getCount(); 
     if ((mCursor != null) && (mCursor.getCount() > 0)) { 
      mCursor.moveToFirst(); 

      do { 
       // Get the data 
       // Convert the initial to String 

       String ID = mCursor.getString(0); 
       String Initial = mCursor.getString(1); 
       String Date = mCursor.getString(2); 
       String SiteLocation = mCursor.getString(3); 
       String WardClinic = mCursor.getString(4); 

       // Indicate that it's successful 
       Log.i("Successful retrival of", Initial); 

       HashMap<String, String> map = new HashMap<String, String>(); 

       map.put(TAG_E_ID, ID); 
       map.put(TAG_E_INITIAL, Initial); 
       map.put(TAG_E_DATE, "Last Diagnosis: " + Date); 
       map.put(TAG_E_SITELOCATION, "Location: " + SiteLocation); 
       map.put(TAG_E_WARDCLINIC, "Ward: " + WardClinic); 

       // Add it to the array such that i can handle the array 
       // afterwhich 
       encouterlist.add(map); 

      } 
      // move to the next row 
      while (mCursor.moveToNext()); 
     } 

     filterText = (EditText) findViewById(R.id.patientDetailsSearch); 
     filterText.addTextChangedListener(filterTextWatcher); 
     // need to link the layout 
     patientList = (ListView) findViewById(R.id.PatientDetailslist); 




     patientList.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() { 

      @Override 
      public boolean onItemLongClick(AdapterView<?> parent, View view, 
        int position, long id) { 
       String str = encouterlist.get(+position).get("e_id"); 
       String name = encouterlist.get(+position).get("entry_initial"); 
       patientDB.open(); 

       patientDB.removeEntry(str); 
       patientDB.close(); 
     //  PatientDetails.this.recreate(); 

       Toast.makeText(myContext, name + " Deleted", Toast.LENGTH_SHORT).show(); 

       // TODO Auto-generated method stub 
       return true; 
      } 

     } 
     ); 

     patientList 
       .setOnItemClickListener(new AdapterView.OnItemClickListener() { 

        @Override 
        public void onItemClick(AdapterView<?> parent, View view, 
          int position, long id) { 
         Toast.makeText(
           PatientDetails.this, 
           encouterlist.get(+position) 
             .get("entry_initial") + " Selected", 
           Toast.LENGTH_SHORT).show(); 
         Intent localIntent = new Intent(PatientDetails.this, 
           PatientInfo.class); 
         String str = encouterlist.get(+position).get("e_id"); 
         localIntent.putExtra("value", str); 
         PatientDetails.this.setResult(-1, localIntent); 
         PatientDetails.this.finish(); 
        } 


       } 

       ); 
     ListAdapter adapter = new SimpleAdapter(PatientDetails.this, 
       encouterlist, R.layout.list_patient, new String[] { TAG_E_ID, 
         TAG_E_INITIAL, TAG_E_DATE, TAG_E_SITELOCATION, 
         TAG_E_WARDCLINIC }, new int[] { R.id.eid, 
         R.id.epatientInitial, R.id.epatientDate, 
         R.id.epatientSiteLocation, R.id.epatientWardClinci }); 

    this.patientList.setAdapter(adapter); 


     }; 

     private TextWatcher filterTextWatcher = new TextWatcher() { 

      public void afterTextChanged(Editable s) { 
      } 

      public void beforeTextChanged(CharSequence s, int start, int count, 
        int after) { 
      } 

      public void onTextChanged(CharSequence s, int start, int before, 
        int count) { 
       adapter.getFilter().filter(s); 
      } 

     }; 


    protected void onDestroy() { 
     super.onDestroy(); 
     filterText.removeTextChangedListener(filterTextWatcher); 
    } 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.patient_details, menu); 
     return true; 
    } 

}

logcat的

12-09 17:01:07.600: E/AndroidRuntime(25728): FATAL EXCEPTION: main 
12-09 17:01:07.600: E/AndroidRuntime(25728): java.lang.NullPointerException 
12-09 17:01:07.600: E/AndroidRuntime(25728): at com.example.medilearner.PatientDetails$1.onTextChanged(PatientDetails.java:166) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.widget.TextView.sendOnTextChanged(TextView.java:7426) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.widget.TextView.handleTextChanged(TextView.java:7488) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:9260) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.text.SpannableStringBuilder.sendTextChanged(SpannableStringBuilder.java:962) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:496) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:435) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:30) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.view.inputmethod.BaseInputConnection.replaceText(BaseInputConnection.java:676) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.view.inputmethod.BaseInputConnection.setComposingText(BaseInputConnection.java:435) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:333) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:77) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.os.Handler.dispatchMessage(Handler.java:99) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.os.Looper.loop(Looper.java:137) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at android.app.ActivityThread.main(ActivityThread.java:4921) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at java.lang.reflect.Method.invokeNative(Native Method) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at java.lang.reflect.Method.invoke(Method.java:511) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794) 
12-09 17:01:07.600: E/AndroidRuntime(25728): at dalvik.system.NativeStart.main(Native Method)

來源

2013-12-09 Walalala

回答

1

這是因爲

public void onTextChanged(CharSequence s, int start, int before, 
       int count) { 
    adapter.getFilter().filter(s); 
}

你adapter爲空。您在本地創建ListAdapter adapter，這在範圍之外沒有意義。您可以使用全球版本，而不是在本地創建ListAdapter。

來源

2013-12-09 09:12:20

0

創建列表適配器的本地實例

ListAdapter adapter = new SimpleAdapter(PatientDetails.this ....

，並在你的文字守望者正在使用的memeber adapter

嘗試更改爲

this.adapter = new SimpleAdapter(PatientDetails.this ....

來源

2013-12-09 09:12:13 mihail

0

嗨請到通過代碼示例

import android.app.Activity; 
import android.os.Bundle; 
import android.text.Editable; 
import android.text.TextWatcher; 
import android.widget.ArrayAdapter; 
import android.widget.EditText; 
import android.widget.ListView; 

public class MainActivity extends Activity { 

    // List view 
    private ListView lv; 

    // Listview Adapter 
    ArrayAdapter<String> adapter; 

    // Search EditText 
    EditText inputSearch; 


    // ArrayList for Listview 
    ArrayList<HashMap<String, String>> productList; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     // Listview Data 
     String products[] = {"Dell Inspiron", "HTC One X", "HTC Wildfire S", "HTC Sense", "HTC Sensation XE", 
           "iPhone 4S", "Samsung Galaxy Note 800", 
           "Samsung Galaxy S3", "MacBook Air", "Mac Mini", "MacBook Pro"}; 

     lv = (ListView) findViewById(R.id.list_view); 
     inputSearch = (EditText) findViewById(R.id.inputSearch); 

     // Adding items to listview 
     adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, products); 
     lv.setAdapter(adapter); 

     /** 
     * Enabling Search Filter 
     * */ 
     inputSearch.addTextChangedListener(new TextWatcher() { 

      @Override 
      public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) { 
       // When user changed the Text 
       MainActivity.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       
      } 
     }); 
    }  
}

activity_main.xml中

<?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" > 

    <!-- Editext for Search --> 
    <EditText android:id="@+id/inputSearch" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:hint="Search products.." 
     android:inputType="textVisiblePassword"/> 

    <!-- List View --> 
    <ListView 
     android:id="@+id/list_view" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" /> 

</LinearLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" > 

    <!-- Single ListItem --> 

    <!-- Product Name --> 
    <TextView android:id="@+id/product_name" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:padding="10dip" 
     android:textSize="16dip" 
     android:textStyle="bold"/>  

</LinearLayout>

來源

2013-12-09 09:25:11

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