以下是我的Spinner代码。当我点击Spinner应用程序时崩溃了。我想检查微调器是否为空，然后它应该提供崩溃警告。 ＆＃39;区域＆＃39;是我声明的材质微调器。 xml代码
<TextView
android:text="Region"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtregion"
android:layout_below="@+id/city"/>
<com.weiwangcn.betterspinner.library.material.MaterialBetterSpinner
android:id="@+id/region"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Select Region"
android:layout_below="@+id/txtregion"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
pDialog.dismiss();
Log.d("RESULT",""+s);
if (s != null) {
try {
JSONObject jsonObject = new JSONObject(s);
String error = jsonObject.get("error").toString();
Log.d("RESULT", " " + error);
if (error == "false")
{
try
{
Iterator keys = jsonObject.keys();
JSONObject currentDynamicValue;
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
int i=0;
while (keys.hasNext()) {
// loop to get the dynamic key
String currentDynamicKey = (String) keys.next();
// get the value of the dynamic key
currentDynamicValue = jsonObject.getJSONObject(currentDynamicKey);
list.put(i,currentDynamicValue.get("region_id").toString());
i++;
Log.d("name", "----------------------> " + currentDynamicValue);
final String name = currentDynamicValue.get("region_name").toString();
pin = currentDynamicValue.get("pin").toString();
Toast.makeText(getActivity().getApplicationContext(),"Region Pin"+pin,Toast.LENGTH_SHORT).show();
adapter.add(name);
region.setAdapter(adapter);
region.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String region_name = list.get(i);
if(region != null && adapterView.getSelectedItem() !=null ) {
Toast.makeText(getActivity().getApplicationContext(), "Region Pin" + region_name, Toast.LENGTH_SHORT).show();
postcode.setText(pin);
}
else{
Toast.makeText(getActivity().getApplicationContext(), "Please select Country", Toast.LENGTH_SHORT).show();
}
}
});
}
}
catch(Exception e)
{
}
这是Logcat：
E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Filter.filter(java.lang.CharSequence, android.widget.Filter$FilterListener)' on a null object reference
at android.widget.AutoCompleteTextView.performFiltering(AutoCompleteTextView.java:867)
at com.weiwangcn.betterspinner.library.material.MaterialBetterSpinner.onFocusChanged(MaterialBetterSpinner.java:49)
at android.view.View.handleFocusGainInternal(View.java:5556)
at android.view.View.requestFocusNoSearch(View.java:8565)
at android.view.View.requestFocus(View.java:8544)
at android.view.View.requestFocus(View.java:8511)
at android.view.View.requestFocus(View.java:8490)
at com.weiwangcn.betterspinner.library.material.MaterialBetterSpinner.onTouchEvent(MaterialBetterSpinner.java:74)
at android.view.View.dispatchTouchEvent(View.java:9427)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2451)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1770)
at android.app.Activity.dispatchTouchEvent(Activity.java:2817)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:67)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:67)
at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2412)
at android.view.View.dispatchPointerEvent(View.java:9658)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4828)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4686)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4191)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4244)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4210)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4356)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4218)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4413)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4191)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4244)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4210)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4218)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4191)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6645)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6619)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6562)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRoot
答案 0 :(得分：1)
这是因为您在空对象引用上调用filter(java.lang.CharSequence, android.widget.Filter.FilterListener)方法。
引用为null，因此它不知道如何在运行时处理它。