使用的CursorAdapter導致我的應用程序崩潰

Question

我有兩個類

• 測試
• MyListAdapter

MyListAdapter是延伸的CursorAdapter和測試是類是不知我的我的主要活動類使用MyListAdapter類裏面我的問題是，在測試類中使用MyListAdapter後，我的應用程序啓動良好，但是當我想要去測試活動我的應用程序崩潰，我也想用遊標對象填充我的ListView，但我的代碼不是w請問有沒有語法錯誤或任何形式的異常任何想法？

這裏是MyListAdapter類的代碼

import android.content.Context; 
import android.database.Cursor; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.CursorAdapter; 
import android.widget.TextView; 




public class YourSubjectListAdapter extends CursorAdapter { 



    private LayoutInflater myInflater; 

    //Constructor of the class 
    YourSubjectListAdapter(Context context, Cursor cursor, int flag) { 
     super(context, cursor, flag); 
    myInflater =(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

    } 


    @Override 
    public View newView(Context context, Cursor cursor, ViewGroup viewGroup) { 
// 
     myInflater = LayoutInflater.from(viewGroup.getContext()); 
     //single_row is my custom layout for showing a list item 
     View retView = myInflater.inflate(R.layout.single_row, viewGroup, false); 
     return retView; 
    } 

    @Override 
    public void bindView(View view, Context context, Cursor cursor) { 

     TextView tvSubName = (TextView) view.findViewById(R.id.tvListSubName); 
     TextView tvSubType = (TextView) view.findViewById(R.id.tvListSubType); 

     tvSubType.setText(cursor.getString(cursor.getColumnIndex(StDbOpenHelper.COLUMN_SUBTYPE))); 
     tvSubName.setText(cursor.getString(cursor.getColumnIndex(StDbOpenHelper.COLUMN_SUBNAME))); 


    } 
} 

這裏是我的測試類

import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.os.Bundle; 
import android.support.annotation.Nullable; 
import android.support.v7.app.AppCompatActivity; 
import android.widget.ListView; 

//Note: I have imported all needed classes 

public class Test extends AppCompatActivity { 
    SQLiteDatabase db; 
    private static final String[] bothColumns = {StDbOpenHelper.COLUMN_SUB,StDbOpenHelper.COLUMN_MAIN}; 

    StDataSource ds; 
    ListView testList; 


    @Override 
    protected void onCreate(@Nullable Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.test); 
     //ds is object of my StDataSource class 
     ds = new StDataSource(this); 

     ds.open(); 

     Cursor data= db.query(StDbOpenHelper.TABLE_GOODS, bothColumns, null, null, null, null, null);// <------ here is the error according to stacktrace 

     YourSubjectListAdapter myAdapter = new YourSubjectListAdapter(this, data, 0); 
     testList = (ListView) findViewById(R.id.lvTestList); 
     testList.setAdapter(myAdapter); 
    } 
} 

的代碼，這裏是堆棧跟蹤

10-12 15:27:27.370 1019-1019/ D/libEGL﹕ loaded /system/lib/egl/libEGL_mali.so 
10-12 15:27:27.375 1019-1019/com.myapp.emh.testapp D/libEGL﹕ loaded /system/lib/egl/libGLESv1_CM_mali.so 
10-12 15:27:27.380 1019-1019/com.myapp.emh.testapp D/libEGL﹕ loaded /system/lib/egl/libGLESv2_mali.so 
10-12 15:27:27.385 1019-1019/com.myapp.emh.testapp E/﹕ Device driver API match 
    Device driver API version: 23 
    User space API version: 23 
10-12 15:27:27.385 1019-1019/com.myapp.emh.testapp E/﹕ mali: REVISION=Linux-r3p2-01rel3 BUILD_DATE=Wed Oct 9 21:05:57 KST 2013 
10-12 15:27:27.480 1019-1019/com.myapp.emh.testapp D/OpenGLRenderer﹕ Enabling debug mode 0 
10-12 15:27:28.670 1019-1019/com.myapp.emh.testapp D/dalvikvm﹕ GC_FOR_ALLOC freed 133K, 9% free 10273K/11196K, paused 17ms, total 17ms 
10-12 15:27:28.695 1019-1019/com.myapp.emh.testapp I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.internal.widget.TintTypedArray.getChangingConfigurations 
10-12 15:27:28.695 1019-1019/com.myapp.emh.testapp W/dalvikvm﹕ VFY: unable to resolve virtual method 410: Landroid/content/res/TypedArray;.getChangingConfigurations()I 
10-12 15:27:28.700 1019-1019/com.myapp.emh.testapp D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0002 
10-12 15:27:28.700 1019-1019/com.myapp.emh.testapp I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.internal.widget.TintTypedArray.getType 
10-12 15:27:28.700 1019-1019/com.myapp.emh.testapp W/dalvikvm﹕ VFY: unable to resolve virtual method 432: Landroid/content/res/TypedArray;.getType (I)I 
10-12 15:27:28.700 1019-1019/com.myapp.emh.testapp D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0002 
10-12 15:27:28.840 1019-1019/com.myapp.emh.testapp D/dalvikvm﹕ GC_FOR_ALLOC freed 97K, 8% free 10474K/11356K, paused 25ms, total 25ms 
10-12 15:27:28.840 1019-1019/com.myapp.emh.testapp I/dalvikvm-heap﹕ Grow heap (frag case) to 12.067MB for 1127536-byte allocation 
10-12 15:27:28.865 1019-1030/com.myapp.emh.testapp D/dalvikvm﹕ GC_FOR_ALLOC freed <1K, 8% free 11575K/12460K, paused 28ms, total 28ms 
10-12 15:27:34.415 1019-1019/com.myapp.emh.testapp D/AbsListView﹕ Get MotionRecognitionManager 
10-12 15:27:34.555 1019-1019/com.myapp.emh.testapp I/logtag﹕ Database Opened ! 
10-12 15:27:34.555 1019-1019/com.myapp.emh.testapp D/AndroidRuntime﹕ Shutting down VM 
10-12 15:27:34.555 1019-1019/com.myapp.emh.testapp W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41cad700) 
10-12 15:27:34.575 1019-1019/com.myapp.emh.testapp E/AndroidRuntime﹕ FATAL EXCEPTION: main 
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myapp.emh.testapp/com.myapp.emh.testapp.Test}: java.lang.NullPointerException 
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295) 
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349) 
      at android.app.ActivityThread.access$700(ActivityThread.java:159) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
      at android.os.Handler.dispatchMessage(Handler.java:99) 
      at android.os.Looper.loop(Looper.java:176) 
      at android.app.ActivityThread.main(ActivityThread.java:5419) 
      at java.lang.reflect.Method.invokeNative(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:525) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862) 
      at dalvik.system.NativeStart.main(Native Method) 
    Caused by: java.lang.NullPointerException 
      at com.myapp.emh.testapp.Test.onCreate(Test.java:34) 
      at android.app.Activity.performCreate(Activity.java:5372) 
      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104) 
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2257) 
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349) 
      at android.app.ActivityThread.access$700(ActivityThread.java:159) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
      at android.os.Handler.dispatchMessage(Handler.java:99) 
      at android.os.Looper.loop(Looper.java:176) 
      at android.app.ActivityThread.main(ActivityThread.java:5419) 
      at java.lang.reflect.Method.invokeNative(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:525) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862) 
      at dalvik.system.NativeStart.main(Native Method) 

Answer 1

我要解決我的問題使用ArrayList，ArrayAdapter和Model類，任何對它如何工作感興趣的人都可以檢查這個鏈接。

Using an ArrayAdapter with ListView