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

Question

我对这段代码有疑问

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();
                }
            });

问题是当我单击按钮 Ok_action 时出现此错误：Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference。我觉得问题出在String p1Value = p1.getText().toString();线上，不知道怎么解决。有人可以帮助我吗？

添加输出错误：

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.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

XML

`<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
     android:layout_height="match_parent">
 <LinearLayout
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"></LinearLayout>

 <EditText
    android:id="@+id/Ora_inizio"
    android:inputType="numberDecimal"
    android:digits="0123456789./"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="16dp"
    android:layout_marginLeft="4dp"
    android:layout_marginRight="4dp"
    android:layout_marginBottom="4dp"
    android:hint="Ore" />
 <EditText
    android:id="@+id/Ora_fine"
    android:inputType="date"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="4dp"
    android:layout_marginLeft="4dp"
    android:layout_marginRight="4dp"
    android:layout_marginBottom="16dp"
    android:fontFamily="sans-serif"
    android:hint="data"/>

 <EditText
    android:id="@+id/pause"
    android:inputType="numberDecimal"
    android:digits="0123456789./"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="4dp"
    android:layout_marginLeft="4dp"
    android:layout_marginRight="4dp"
    android:layout_marginBottom="16dp"
    android:fontFamily="sans-serif"
    android:hint=""/>

 <TableRow
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

 <Button
    android:id="@+id/ok_action"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="left"
    android:text="Ok"/>

 <Button
    android:id="@+id/canceldialog"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:text="Cancel"/>
</TableRow>

`

Answer 1

您甚至无需查看源代码，就可以通过错误消息和您陈述的行来判断问题出在哪里。 p1 为空；你试过运行 getText() 了。 Null 没有方法getText()，所以你得到一个空指针异常。

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 找到视图。仔细检查此 ID 是否用于当前布局中的视图。

Answer 2

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 的视图位于扩展到对话框的布局中，即 R.layout.popupdialog.

So you have to use Dialog.findViewById() method.

但现在您正在尝试从 activity 布局 (R.layout.agendalayout) 而不是对话框布局访问此 Edittext。

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

android.text.Editable android.widget.EditText.getText() on application click button

java

android

android-dialog