我开始在开发人员控制台中显示以下NullPointerException以获取我的某个应用
java.lang.NullPointerException at com.lead.soft.deve.myapp.ae.onDateSet(Unknown Source) at
android.app.DatePickerDialog.tryNotifyDateSet(DatePickerDialog.java:148) at
android.app.DatePickerDialog.onStop(DatePickerDialog.java:155) at
android.app.Dialog.dismissDialog(Dialog.java:335) at
android.app.Dialog.dismiss(Dialog.java:311) at
com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:178) at
android.os.Handler.dispatchMessage(Handler.java:99) at
android.os.Looper.loop(Looper.java:155) at
android.app.ActivityThread.main(ActivityThread.java:5454) at
java.lang.reflect.Method.invokeNative(Native Method) at
java.lang.reflect.Method.invoke(Method.java:511) at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029) at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:796) at
dalvik.system.NativeStart.main(Native Method)
我正在使用此代码添加和编辑存储在App MySQL数据库中的日期“DOB”，请注意我删除了不适用于我正在获取的错误的代码
package com.leaders.software.development.myleadersbook;
import java.util.Calendar;
import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.app.Dialog;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
public class tab2 extends Activity implements View.OnClickListener {
Button ConfirmButton, CallSpouseButton, EmailSpouseButton, HomePhoneButton,
WorkPhoneButton, CellPhoneButton, EmailAddressButton, SMSButton;
private static final int HELP_ID = Menu.FIRST;
private Long mRowId;
private NotesDbAdapter mDbHelper;
private TextView mdobText;
private TextView mdobDisplay;
private Button mPickdob;
private Calendar dobDate;
static final int DATE_DIALOG_ID = 0;
private TextView activeDateDisplay;
private Calendar activeDate;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mDbHelper = new NotesDbAdapter(this);
mDbHelper.open();
this.getWindow().setSoftInputMode(
WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
setContentView(R.layout.tab2);
mdobText = (TextView) findViewById(R.id.dob);
/* capture our View elements for the start date function */
mdobDisplay = (TextView) findViewById(R.id.dob);
mPickdob = (Button) findViewById(R.id.pickdob);
/* get the current date */
dobDate = Calendar.getInstance();
/* add a click listener to the button */
mPickdob.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
showDateDialog(mdobDisplay, dobDate);
}
});
mRowId = null;
mRowId = (savedInstanceState == null) ? null
: (Long) savedInstanceState
.getSerializable(NotesDbAdapter.KEY_ROWID);
if (mRowId == null) {
Bundle extras = getIntent().getExtras();
mRowId = extras != null ? extras.getLong(NotesDbAdapter.KEY_ROWID)
: null;
}
populateFields();
private void updateDisplay(TextView dateDisplay, Calendar date) {
dateDisplay.setText(new StringBuilder()
// Month is 0 based so add 1
.append(date.get(Calendar.MONTH) + 1).append("-")
.append(date.get(Calendar.DAY_OF_MONTH)).append("-")
.append(date.get(Calendar.YEAR)).append(" "));
}
public void showDateDialog(TextView dateDisplay, Calendar date) {
activeDateDisplay = dateDisplay;
activeDate = date;
showDialog(DATE_DIALOG_ID);
}
private OnDateSetListener dateSetListener = new OnDateSetListener() {
// @Override
public void onDateSet(DatePicker view, int year, int monthOfYear,
int dayOfMonth) {
activeDate.set(Calendar.YEAR, year);
activeDate.set(Calendar.MONTH, monthOfYear);
activeDate.set(Calendar.DAY_OF_MONTH, dayOfMonth);
updateDisplay(activeDateDisplay, activeDate);
unregisterDateDisplay();
}
};
private void unregisterDateDisplay() {
activeDateDisplay = null;
activeDate = null;
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DATE_DIALOG_ID:
return new DatePickerDialog(this, dateSetListener,
activeDate.get(Calendar.YEAR),
activeDate.get(Calendar.MONTH),
activeDate.get(Calendar.DAY_OF_MONTH));
}
return null;
}
@Override
protected void onPrepareDialog(int id, Dialog dialog) {
super.onPrepareDialog(id, dialog);
switch (id) {
case DATE_DIALOG_ID:
((DatePickerDialog) dialog).updateDate(
activeDate.get(Calendar.YEAR),
activeDate.get(Calendar.MONTH),
activeDate.get(Calendar.DAY_OF_MONTH));
break;
}
}
private void populateFields() {
if (mRowId != null) {
Cursor note = mDbHelper.fetchNote(mRowId);
startManagingCursor(note);
mdobText.setText(note.getString(note
.getColumnIndexOrThrow(NotesDbAdapter.KEY_DOB)));
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
saveState();
outState.putSerializable(NotesDbAdapter.KEY_ROWID, mRowId);
}
@Override
protected void onDestroy() {
super.onDestroy();
if (mDbHelper != null) {
mDbHelper.close();
}
}
@Override
protected void onPause() {
super.onPause();
saveState();
}
@Override
protected void onResume() {
super.onResume();
populateFields();
}
private void saveState() {
String dob = mdobText.getText().toString();
if (mRowId == null) {
long id = mDbHelper.createNote(dob);
if (id > 0) {
mRowId = id;
}
} else {
mDbHelper.updateNote(mRowId, dob);
}
}
}
在黑暗中拍摄时我将以下内容添加到Manifest文件中。但仍然没有运气
android:configChanges="orientation"
我将上面的代码添加到我的Manifest文件后，在运行版本2.3的测试手机上不再出现此错误，但其他一些代码仍然存在
可能是“”
之间的空间.append(date.get(Calendar.YEAR)).append(" "));
我也发现了这个搜索
在活动中添加此代码：
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
}
并在清单文件中使用它：
<activity android:name="MyActivity" android:label="@string/app_name"
android:configChanges="orientation|keyboardHidden"></activity>
这是一个好的解决方法