Question

我的代码存在问题

$(function() {

$('.reset').on('click',function () {
  $(':checkbox').prop('checked',false);
  $(':text').hide();
  $('.applabel').show();  
});

$('.edit').on('click',function () {
   $('.ed-up').each(function(){
       if($('.ed-up').prop('checked') == true)
      alert($(this).next('.applabel').text()); 

   });
});

 });

问题是当我单击按钮Ok_action时出现此错误：尝试在空对象引用上调用虚拟方法'android.text.Editable android.widget.EditText.getText（）'。我认为问题出在public class AgendaActivity extends AppCompatActivity { private DbManager db=null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.agendalayout); db=new DbManager(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.addxml, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.action_settings: // User chose the "Settings" item, show the app settings UI... return true; case R.id.action_add: final Dialog d = new Dialog(this); d.setTitle("Prova"); d.setCancelable(false); d.setContentView(R.layout.popupdialog); Window window = d.getWindow(); window.setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); d.show(); //eventi Button Button b = (Button) d.findViewById(R.id.ok_action); b.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { EditText p1 = (EditText) findViewById(R.id.Ora_inizio); EditText p2 = (EditText) findViewById(R.id.Ora_fine); EditText p3 = (EditText) findViewById(R.id.pause); String p1Value = p1.getText().toString(); String p2Value = p2.getText().toString(); String p3Value = p3.getText().toString(); try { int p1Final = Integer.parseInt(p1Value); } catch (Exception e) { Toast exceptionAgenda = Toast.makeText(AgendaActivity.this, "Uno dei due campi o entrambi sono vuoti!", Toast.LENGTH_LONG); exceptionAgenda.show(); } //db.save(primoValore,secondoValore,terzoValore); } }); default: } return true; }; } } }); Button b2=(Button) d.findViewById(R.id.canceldialog); b2.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { Toast.makeText(d.getContext(), "cliccatocancel", Toast.LENGTH_LONG).show(); d.cancel(); } });行，我不知道如何解决。有人能帮助我吗？

添加输出错误：

String p1Value = p1.getText().toString();

XML

11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:         FATAL EXCEPTION: main
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime: Process: com.apps.giak.lavorotime, PID: 16356
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at com.apps.giak.lavorotime.AgendaActivity$1.onClick(AgendaActivity.java:62)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at android.view.View.performClick(View.java:5155)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:20747)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:739)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5832)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
11-06 13:03:24.747 16356-16356/com.apps.giak.lavorotime E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteIn

`

Answer 1

请使用

EditText p1 = (EditText) d.findViewById(R.id.Ora_inizio);

而不是

EditText p1 = (EditText) findViewById(R.id.Ora_inizio);

因为ID为R.id.Ora_inizio的视图位于对话框中，即R.layout.popupdialog。

所以你必须使用Dialog.findViewById()方法。

但现在您尝试从活动布局Edittext而不是对话框布局中访问此(R.layout.agendalayout)。

Answer 2

你可以告诉 - 甚至没有查看你的源代码 - 问题是什么，只是错误信息和你说的那一行。 p1为空;并且您尝试在其上运行getText()。 Null没有方法getText()，因此您获得空指针异常。

findViewById(R.id.Ora_inizio)可能返回null，这意味着Android无法在当前布局中通过该ID查找视图。仔细检查此ID是否用于当前布局中的视图。

android.text.Editable android.widget.EditText.getText（）在应用程序单击按钮上

2 个答案: