无法加载应用程序，并且显示空指针错误。错误类似于“ java.lang.NullPointerException：尝试在null上调用虚拟方法'void android.widget.TextView.setText（java.lang.CharSequence）'”对象引用”
我已经在另一个活动中编写了相同的代码，在那边它可以工作，但是在这里不起作用。我想在textview点击上显示日期选择器。
这是我的Java类代码：
public class AdminProfileActivity extends Fragment {
DatePickerDialog picker;
private String date;
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootview = inflater.inflate(R.layout.activity_custom_calendar, container, false);
final Calendar myCalendar = Calendar.getInstance();
final TextView txtDate=(TextView) rootview.findViewById(R.id.txtBirtday);
final SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
date = dateFormat.format(Calendar.getInstance().getTime());
txtDate.setText(date);
txtDate.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final Calendar cldr = Calendar.getInstance();
int day = cldr.get(Calendar.DAY_OF_MONTH);
int month = cldr.get(Calendar.MONTH);
int year = cldr.get(Calendar.YEAR);
// date picker dialog
picker = new DatePickerDialog(getActivity(),new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
txtDate.setText(dayOfMonth + "/" + (monthOfYear + 1) + "/" + year);
}
}, year, month, day);
picker.getDatePicker().setSpinnersShown(true);
picker.getDatePicker().setCalendarViewShown(false);
picker.show();
}
});
return rootview;
}
}
这是.XML文件代码：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".AdminProfileActivity"
android:orientation="vertical"
android:padding="15dp"
android:layout_margin="10dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="#fff">
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputName"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtName"
android:hint="Enter Your Name"
android:inputType="text"/>
</android.support.design.widget.TextInputLayout>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Select Birthdate"
android:textColor="#0E0D0D"
android:layout_marginRight="5dp"
android:layout_marginBottom="5dp"
android:textSize="22dp"
android:id="@+id/txtBirtday"
android:focusable="false"
/>
<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/gender"
android:layout_below="@+id/mrname_layout"
android:orientation="horizontal">
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/rbtnMale"
android:checked="true"
android:text="Male"
android:textSize="20dp"
/>
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/rbtnFemale"
android:text="Female"
android:textSize="20dp"/>
</RadioGroup>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputAddress"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtAddress"
android:hint="Enter Your Address"
android:inputType="textMultiLine" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputCity"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtCity"
android:hint="City"
android:inputType="text" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputState"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtState"
android:hint="State"
android:inputType="text" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputCountry"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtCountry"
android:hint="Country"
android:inputType="text" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputPhone"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtPhone"
android:hint="Mobile Number"
android:inputType="textPhonetic" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtInputEmail"
app:errorEnabled="true"
android:textColorHint="#0E0D0D">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtEmail"
android:hint="Email Address"
android:inputType="textEmailAddress" />
</android.support.design.widget.TextInputLayout>
<android.support.v7.widget.AppCompatButton
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Save Profile"
android:background="#1D77D6"
android:id="@+id/btnSave"
android:textColor="#fff"
android:layout_gravity="bottom"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
android:textAllCaps="false"
android:textSize="20dp"/>
</LinearLayout>