与onItemSelected一起使用2个spinners

Question

我已经看了几个线程，并没有在那里提出的建议似乎解决了我有问题。我在同一项活动中有两名纺纱人员。我从一个微调器中选择的值是为了填充另一个微调器，然后我想从第二个微调器中选择一个值。它一直工作，直到我点击第二个微调器被动态填充后，然后应用程序崩溃。我不知道还有什么要做。我将发布我的相关代码以及我收到的错误消息。

public void onCreate(Bundle savedInstanceState) 
{ 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.bodyregionandpart_layout); 
    bodyRegion = (Spinner) findViewById(R.id.bodyregion); 
    // Create an ArrayAdapter using the string array and a default spinner layout 
    bodyRegionAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, bodyregion); 
    // Specify the layout to use when the list of choices appears 
    bodyRegionAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    // Apply the adapter to the spinner 
    bodyRegion.setAdapter(bodyRegionAdapter); 
    //Sets the spinner to listen when an item is selected 
    bodyRegion.setOnItemSelectedListener(this); 
} 

public void onItemSelected(AdapterView<?> parent, View view, 
     int pos, long id) 
{ 
    if(parent.getId() == R.id.bodyregion) 
    { 
     switch(pos) 
      { 
      case 1: 
       FillSpinner(Head); 
       Log.d("bodyregion", "This is Head"); 
       break; 
      }      
    } 
    else if(parent.getId() == R.id.bodypart) 
    { 
     Log.d("bodypart", "This is body part: " + (String) parent.getItemAtPosition(pos)); 
    } 
} 

public void onNothingSelected(AdapterView<?> parent) 

{ 
    // Another interface callback 
} 

public void FillSpinner(String[] a) 
{ 
    //Fills array with contents of a 
    for(int i = 0; i < a.length; i++) 
    { 
     array[i] = a[i]; 
    } 
    bodyPart = (Spinner) findViewById(R.id.bodypart); 
    // Create an ArrayAdapter using the string array and a default spinner layout 
    bodyPartAdapter = new ArrayAdapter<String>(this, 
      android.R.layout.simple_spinner_item, array); 
    // Specify the layout to use when the list of choices appears 
    bodyPartAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    // Apply the adapter to the spinner 
    bodyPart.setAdapter(bodyPartAdapter); 
    bodyPart.setOnItemSelectedListener(this); 
} 

然后这是我收到错误消息：

01-21 22:10:29.616: D/bodyregion(2855): This is Head 
01-21 22:10:29.715: D/bodypart(2855): This is body part: Choose Body Part 
01-21 22:10:31.385: D/AndroidRuntime(2855): Shutting down VM 
01-21 22:10:31.385: W/dalvikvm(2855): threadid=1: thread exiting with uncaught exception (group=0x40a13300) 
01-21 22:10:31.415: E/AndroidRuntime(2855): FATAL EXCEPTION: main 
01-21 22:10:31.415: E/AndroidRuntime(2855): java.lang.NullPointerException 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:394) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.ArrayAdapter.getDropDownView(ArrayAdapter.java:415) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.Spinner$DropDownAdapter.getDropDownView(Spinner.java:725) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.Spinner$DropDownAdapter.getView(Spinner.java:721) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.Spinner.measureContentWidth(Spinner.java:669) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.Spinner$DropdownPopup.show(Spinner.java:948) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.widget.Spinner.performClick(Spinner.java:597) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.view.View$PerformClick.run(View.java:16966) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.os.Handler.handleCallback(Handler.java:615) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.os.Handler.dispatchMessage(Handler.java:92) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.os.Looper.loop(Looper.java:137) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at android.app.ActivityThread.main(ActivityThread.java:4745) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at java.lang.reflect.Method.invokeNative(Native Method) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at java.lang.reflect.Method.invoke(Method.java:511) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
01-21 22:10:31.415: E/AndroidRuntime(2855):  at dalvik.system.NativeStart.main(Native Method) 

第二日志信息只会显示在微调的首选创建时。一旦我点击它来选择其他东西就会崩溃。任何帮助/建议表示赞赏。谢谢。

Answer 1

做小change..check如果数组的长度大于0则仅设置适配器更大的第二微调

public void FillSpinner(String[] a) 
    { 
     //Fills array with contents of a 
     for(int i = 0; i < a.length; i++) 
     { 
      array[i] = a[i]; 
     } 
     if(array.length>0) 
     { 
      bodyPart = (Spinner) findViewById(R.id.bodypart); 
      // Create an ArrayAdapter using the string array and a default spinner layout 
      bodyPartAdapter = new ArrayAdapter<String>(this, 
        android.R.layout.simple_spinner_item, array); 
      // Specify the layout to use when the list of choices appears 
      bodyPartAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
      // Apply the adapter to the spinner 
      bodyPart.setAdapter(bodyPartAdapter); 
      bodyPart.setOnItemSelectedListener(this); 
     } 

    }