android.widget.AdapterView.fireOnSelected(AdapterView.java:892)
android.widget.AdapterView.fireOnSelected(AdapterView.java:892)
提问于 2013-12-08 14:04:43
当我打算驱逐thirdactivity.class时，Logcat说，这是什么意思？这项活动已经建立起来了。但是当模仿的时候，这个过程就停止了。
11-11 10:17:25.824: E/AndroidRuntime(3207): java.lang.NullPointerException
11-11 10:17:25.824: E/AndroidRuntime(3207): at com.example.andrappexp1.ThirdActivity$2.onItemSelected(ThirdActivity.java:58)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.widget.AdapterView.fireOnSelected(AdapterView.java:892)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.widget.AdapterView.access$200(AdapterView.java:49)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:860)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.os.Handler.handleCallback(Handler.java:730)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.os.Handler.dispatchMessage(Handler.java:92)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.os.Looper.loop(Looper.java:137)
11-11 10:17:25.824: E/AndroidRuntime(3207): at android.app.ActivityThread.main(ActivityThread.java:5103)
11-11 10:17:25.824: E/AndroidRuntime(3207): at java.lang.reflect.Method.invokeNative(Native Method)
11-11 10:17:25.824: E/AndroidRuntime(3207): at java.lang.reflect.Method.invoke(Method.java:525)
11-11 10:17:25.824: E/AndroidRuntime(3207): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
11-11 10:17:25.824: E/AndroidRuntime(3207): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-11 10:17:25.824: E/AndroidRuntime(3207): at dalvik.system.NativeStart.main(Native Method)thirdactivity.class中的旋转器是这样的，
Spinner spinner = (Spinner) findViewById(R.id.spinner1);
this.mAdapter = ArrayAdapter.createFromResource(this, R.array.Cities,
android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(this.mAdapter);
spinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1,int arg2, long arg3) {
// TODO Auto-generated method stub
//Toast.makeText(parent.getContext(),"The planet is " + parent.getItemAtPosition(pos).toString(),Toast.LENGTH_LONG).show();
textViewa.setText("You choose :"+ " " + mAdapter.getItem(arg2));
arg0.setVisibility(View.VISIBLE);
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
textViewa.setText("NONE");
arg0.setVisibility(View.VISIBLE);
}
}); 正如我所怀疑的，textviewa的语句确实是一个问题。我把它变成吐司，就像这个：
toast = Toast.makeText(getApplicationContext(), "Defined Toast",
Toast.LENGTH_LONG); toast.setGravity(Gravity.CENTER, 0, 0);
toast.show(); 一切都很好。
现在我发现了忘记从Id绑定txtview的原因。这是我的粗心。现在添加语句：
TextView textViewa=(TextView) findViewById(R.Id.textView1); 他们表现得很完美。同样的谢谢你。
回答 2
Stack Overflow用户
发布于 2013-12-08 17:28:58
好的，然后使用下面的代码获得Spinner选择：
spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
System.out.println();
textViewa.setText("You choose :"+ " " + ((TextView) arg1).getText().toString());
}Stack Overflow用户
发布于 2013-12-10 11:14:58
现在，我发现了忘记从Id绑定txtview的原因。这是我的粗心。现在添加以下语句：
TextView textViewa=(TextView) findViewById(R.Id.textView1); 他们表现得很完美。同样的谢谢你。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/20454307
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