我正在尝试从按钮的onClick添加一个挂起的意图来实现警报，但我得到一个空指针异常＆＃34;在android：app.PendingIntent.getActivity（PendingIntent.java:257）＆＃34;和＆＃34;在android：app.PendingIntent.getActivity（PendingIntent.java:224）＆＃34;。
这是我的代码点击＆＃34; ADD＆＃34;按钮应该创建Pending Intent。
public class DisplayAlertMessage extends Activity {
private int mYear, mMonth, mDay, mHour, mMinute;
private long alarm_time;
private int rem = 0;
private String date,time;
private String lists1[] = new String[10];
static final int DATE_DIALOG_ID = 999;
@SuppressLint("InflateParams")
public void displayAlertDialog(LayoutInflater inflater,final MainActivity obj,final MainActivity obj1,final Context con) {
/** This intent invokes the activity DemoActivity, which in turn opens the AlertDialog window */
final Intent in = new Intent("com.example.todotry_1.demoactivity");
final View alertLayout = inflater.inflate(R.layout.layout_custom_dialog, null);
final EditText Note = (EditText) alertLayout.findViewById(R.id.Note);
final EditText Lists = (EditText) alertLayout.findViewById(R.id.Lists);
final TextView Remind = (TextView) alertLayout.findViewById(R.id.Remind);
final TextView Time = (TextView) alertLayout.findViewById(R.id.Time);
final TextView Date = (TextView) alertLayout.findViewById(R.id.Date);
final TextView Timeval = (TextView) alertLayout.findViewById(R.id.Timeval);
final TextView Dateval = (TextView) alertLayout.findViewById(R.id.Dateval);
final ImageView iv=(ImageView) alertLayout.findViewById(R.id.img);
i=iv;
AlertDialog.Builder alert = new AlertDialog.Builder(obj,R.style.DialogTheme);
Remind.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d("onCLICK","REMIND");
Toast.makeText(con, "REMIND CLICKED", Toast.LENGTH_SHORT).show();
Remind.setVisibility(View.GONE);
Time.setVisibility(View.VISIBLE);
Date.setVisibility(View.VISIBLE);
rem = 1;
Time.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
final Calendar c = Calendar.getInstance();
mHour = c.get(Calendar.HOUR_OF_DAY);
mMinute = c.get(Calendar.MINUTE);
// Launch Time Picker Dialog
TimePickerDialog tpd = new TimePickerDialog(obj,new TimePickerDialog.OnTimeSetListener()
{
@Override
public void onTimeSet(TimePicker view, int hourOfDay,int minute) {
// Display Selected time in textbox
Timeval.setVisibility(View.VISIBLE);
Timeval.setText(hourOfDay + ":" + minute);
}
}, mHour, mMinute, false);
tpd.show();
time = mHour+":"+mMinute;
}
});
Date.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
final Calendar c = Calendar.getInstance();
mYear = c.get(Calendar.YEAR);
mMonth = c.get(Calendar.MONTH);
mDay = c.get(Calendar.DAY_OF_MONTH);
// Launch Date Picker Dialog
DatePickerDialog dpd = new DatePickerDialog(obj,new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
// Display Selected date in textbox
Dateval.setVisibility(View.VISIBLE);
Dateval.setText(dayOfMonth + "-"+ (monthOfYear + 1) + "-" + year);
}
}, mYear, mMonth, mDay);
dpd.show();
date = mDay+"-"+mMonth+"-"+mYear;
}
});
GregorianCalendar calendar = new GregorianCalendar(mYear,mMonth,mDay, mHour, mMinute);
alarm_time = calendar.getTimeInMillis();
}
});
alert.setTitle("ADD NOTE");
alert.setView(alertLayout);
alert.setCancelable(false);
alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(con, "Cancel clicked", Toast.LENGTH_SHORT).show();
}
});
alert.setPositiveButton("ADD", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// code for matching password
String note = Note.getText().toString();
String lists = Lists.getText().toString() + '\n';
int l=lists.length();
int i=0;
String one="";
char q;
String main1="";
int count = 0,j=0;
for (i=0;i<l;i++)
{
q=lists.charAt(i);
if(q!='\n' )
one += q;
else
{
Log.d("the string",":" + one);
//Toast.makeText(getBaseContext(), "Words " + one , Toast.LENGTH_SHORT).show();
main1 += count + " : " + one;
lists1[j++] = one;
one="";
}
count++;
}
Log.d("DISplay","111before finish add");
if((date == null)^(time == null))
{
Toast.makeText(con, "Enter both date and time to set alarm", Toast.LENGTH_SHORT).show();
}
else{
TaskDBHelper ob = new TaskDBHelper(obj1);
SQLiteDatabase sqlDB = ob.getWritableDatabase();
if((date != null)&(time != null))
{
String f1 = String.format("INSERT INTO prioritised (task,date,time,ringtone,done,Hidden) VALUES('"+note+"','"+date+"','"+time+"','"+""+"',0,"+MainActivity.getStat()+")");
sqlDB.execSQL(f1);
if((j!=0)&(main1!="\n") )
{
int id=0;
Cursor cursor = sqlDB.rawQuery("SELECT _id from prioritised where task = '"+note+"'",null);
if (cursor != null) {
try {
if (cursor.moveToFirst()) {
id = cursor.getInt(0);
}
} finally {
cursor.close();
}
}
Log.d("Prio"," "+id);
String add;
for(int k=0;k<j;k++)
{
add = String.format("INSERT INTO sublistprioritised (_id1,sublist,done,hidden) VALUES("+id+",'"+lists1[k]+"',0,"+MainActivity.getStat()+")");
sqlDB.execSQL(add);
}
}
/** Creating a Pending Intent */
Context x=getBaseContext();
int requestID = (int) System.currentTimeMillis();
PendingIntent operation = PendingIntent.getActivity(x, requestID, in,Intent.FLAG_ACTIVITY_NEW_TASK);
/** Getting a reference to the System Service ALARM_SERVICE */
AlarmManager alarmManager = (AlarmManager) x.getSystemService(ALARM_SERVICE);
/** Setting an alarm, which invokes the operation at alart_time */
alarmManager.set(AlarmManager.RTC_WAKEUP , alarm_time , operation);
/** Alert is set successfully */
Toast.makeText(x, "Alarm is set successfully",Toast.LENGTH_SHORT).show();
}
else{
String f2 = String.format("INSERT INTO unprioritised (task,done,Hidden) VALUES('"+note+"',0,"+MainActivity.getStat()+")");
sqlDB.execSQL(f2);
if((j!=0)&(main1!="\n") )
{
int id=0;
Cursor cursor = sqlDB.rawQuery("SELECT _id from unprioritised where task = '"+note+"'",null);
if (cursor != null) {
try {
if (cursor.moveToFirst()) {
id = cursor.getInt(0);
}
} finally {
cursor.close();
}
}
String add;
for(int k=0;k<j;k++)
{
add = String.format("INSERT INTO sublistunprioritised (_id1,sublist,done,Hidden) VALUES("+id+",'"+lists1[k]+"',0,"+MainActivity.getStat()+")");
sqlDB.execSQL(add);
}
}
}
}
}
});
AlertDialog dialog = alert.create();
dialog.show();
}
}
谢谢。任何帮助表示赞赏。
这里是Logcat
04-02 13:38:03.922: E/AndroidRuntime(2120): FATAL EXCEPTION: main
04-02 13:38:03.922: E/AndroidRuntime(2120): Process: com.example.todotry_1, PID: 2120
04-02 13:38:03.922: E/AndroidRuntime(2120): java.lang.NullPointerException
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.app.PendingIntent.getActivity(PendingIntent.java:257)
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.app.PendingIntent.getActivity(PendingIntent.java:224)
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.example.todotry_1.DisplayAlertMessage$4.onClick(DisplayAlertMessage.java:244)
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.os.Handler.dispatchMessage(Handler.java:102)
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.os.Looper.loop(Looper.java:136)
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-02 13:38:03.922: E/AndroidRuntime(2120): at java.lang.reflect.Method.invokeNative(Native Method)
04-02 13:38:03.922: E/AndroidRuntime(2120): at java.lang.reflect.Method.invoke(Method.java:515)
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-02 13:38:03.922: E/AndroidRuntime(2120): at dalvik.system.NativeStart.main(Native Method)
更新了日志：
04-02 15:59:03.140: E/AndroidRuntime(1880): android.database.sqlite.SQLiteConstraintException: columns _id1, sublist are not unique (code 19)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteConnection.nativeExecuteForChangedRowCount(Native Method)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteConnection.executeForChangedRowCount(SQLiteConnection.java:734)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteSession.executeForChangedRowCount(SQLiteSession.java:754)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:64)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1674)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1603)
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.example.todotry_1.DisplayAlertMessage$4.onClick(DisplayAlertMessage.java:236)
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.os.Handler.dispatchMessage(Handler.java:102)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.os.Looper.loop(Looper.java:136)
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-02 15:59:03.140: E/AndroidRuntime(1880): at java.lang.reflect.Method.invokeNative(Native Method)
04-02 15:59:03.140: E/AndroidRuntime(1880): at java.lang.reflect.Method.invoke(Method.java:515)
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-02 15:59:03.140: E/AndroidRuntime(1880): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
在此处调用getBaseContext()似乎没有必要，您可能不想使用currentTimeMillis()作为requestCode，以防您需要取消PendingIntent：
/** Creating a Pending Intent */
//Context x=getBaseContext();
//int requestID = (int) System.currentTimeMillis();
PendingIntent operation = null;
//Make sure nothing is null for debugging purposes
if (con == null){
Log.e("onCLICK","con is null");
}
else if (in == null){
Log.e("onCLICK","in is null");
}
else{
operation = PendingIntent.getActivity(con, 0, in,PendingIntent.FLAG_UPDATE_CURRENT);
}
if (operation != null){
/** Getting a reference to the System Service ALARM_SERVICE */
AlarmManager alarmManager = (AlarmManager) con.getSystemService(ALARM_SERVICE);
/** Setting an alarm, which invokes the operation at alart_time */
alarmManager.set(AlarmManager.RTC_WAKEUP , alarm_time , operation);
/** Alert is set successfully */
Toast.makeText(con, "Alarm is set successfully",Toast.LENGTH_SHORT).show();
}
请看一下这篇文章的例子：PendingIntent works correctly for the first notification but incorrectly for the rest
编辑：我只是将PendingIntent代码放入AndroidStudio，它给了我这条消息：
必须是以下一项或多项：PendingIntent.FLAG_ONE_SHOT， PendingIntent.FLAG_NO_CREATE，PendingIntent.FLAG_CANCEL_CURRENT， PendingIntent.FLAG_UPDATE_CURRENT，Intent.FILL_IN_ACTION， Intent.FILL_IN_DATA，Intent.FILL_IN_CATEGORIES， Intent.FILL_IN_COMPONENT，Intent.FILL_IN_PACKAGE， Intent.FILL_IN_SOURCE_BOUNDS，Intent.FILL_IN_SELECTOR， Intent.FILL_IN_CLIP_DATA less ...（Ctrl + F1）报告两种类型 问题：提供错误类型的资源标识符。对于 例如，在调用Resources.getString（int id）时，你应该这样做 传递R.string.something，而不是R.drawable.something。通过 假定一个特定集合的方法的错误常量 常量。例如，在调用View＃setLayoutDirection时， 参数必须是android.view.View.LAYOUT_DIRECTION_LTR或 android.view.View.LAYOUT_DIRECTION_RTL。
请查看The Documentation以获取有关此处使用的有效标志的更多信息。