My android project always get crash/force close when i pick date

my android project get crash/force close when i pick some date

this is my xml code :

<EditText
android:id="@+id/tvDate"
android:layout_width="174dp"
android:layout_height="40dp"
android:layout_marginTop="24dp"
android:ems="10"
android:inputType="date|time"
app:layout_constraintEnd_toEndOf="@+id/cbr"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="@+id/cbr"
app:layout_constraintTop_toBottomOf="@+id/cbr" />

and this is my InputUser.java file code:

 protected void onCreate(Bundle savedInstanceState) {
nama=(EditText)findViewById(R.id.name);
/*email=(Switch)findViewById(R.id.switch1);*/
wsomething=(EditText)findViewById(R.id.wSome);
btnSave=(Button)findViewById(R.id.btnsave);
btnClear=(Button)findViewById(R.id.btnclear);
btnChange=(Button)findViewById(R.id.btnImg);
radLaki=(RadioButton)findViewById(R.id.rbl);
radPerempuan=(RadioButton)findViewById(R.id.rbp);
chbSekolah=(CheckBox)findViewById(R.id.cbs);
chbRumah=(CheckBox)findViewById(R.id.cbr);
tvDateRes=(EditText)findViewById(R.id.tvDate);
btnPick=(Button)findViewById(R.id.btnTime);
ivImage=(ImageView)findViewById(R.id.Img);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_input_user);
Button btnTime = (Button)findViewById(R.id.btnTime);
dateFormatter = new SimpleDateFormat("dd-MM-yyyy", Locale.US);
btnTime.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showDateDialog();
}
});
}

and this is the method:

private void showDateDialog()
{
Calendar newcalendar= Calendar.getInstance();
DatePickerDialog datePickerDialog=new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
Calendar newDate = Calendar.getInstance();
newDate.set(year, monthOfYear, dayOfMonth);
tvDateRes.setText(dateFormatter.format(newDate.getTime()));
}
}, newcalendar.get(Calendar.YEAR), newcalendar.get(Calendar.MONTH), newcalendar.get(Calendar.DAY_OF_MONTH));
datePickerDialog.show();
}

i dont know how but its always said

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.EditText.setText(java.lang.CharSequence)' on a null object reference
stacktrace: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.EditText.setText(java.lang.CharSequence)' on a null object reference
at com.example.belajarlayout.InputUser$2.onDateSet(InputUser.java:126)
at android.app.DatePickerDialog.onClick(DatePickerDialog.java:171)
at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:172)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6739)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:495)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:859)

can you guys help me?

You didn't set setContentView(R.layout.xxx) in function onCreate.

The code should be like this :

@Override
public void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.xxx);
nama=(EditText)findViewById(R.id.name);
/*email=(Switch)findViewById(R.id.switch1);*/
wsomething=(EditText)findViewById(R.id.wSome);
btnSave=(Button)findViewById(R.id.btnsave);
btnClear=(Button)findViewById(R.id.btnclear);
btnChange=(Button)findViewById(R.id.btnImg);
radLaki=(RadioButton)findViewById(R.id.rbl);
radPerempuan=(RadioButton)findViewById(R.id.rbp);
chbSekolah=(CheckBox)findViewById(R.id.cbs);
chbRumah=(CheckBox)findViewById(R.id.cbr);
tvDateRes=(EditText)findViewById(R.id.tvDate);
btnPick=(Button)findViewById(R.id.btnTime);
ivImage=(ImageView)findViewById(R.id.Img);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_input_user);
Button btnTime = (Button)findViewById(R.id.btnTime);
dateFormatter = new SimpleDateFormat("dd-MM-yyyy", Locale.US);
btnTime.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showDateDialog();
}
});
}

Move these two lines to before you set your views

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_input_user);

On the side, I suggest you use View Binding to avoid such errors in the future. Another thing is you don't need to case anymore with findViewById.

You can't call findViewById before calling super.onCreate(savedInstanceState); and setContentView(R.layout.activity_input_user); And you must create object of your views. For example TextView etc.

so rearrange your codes.

private EditText name;
private EditText wsomething;
private Button btnSave;
private Button btnChange;
//all other views also...

 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_input_user);

    name=(EditText)findViewById(R.id.name);
    /*email=(Switch)findViewById(R.id.switch1);*/
    wsomething=(EditText)findViewById(R.id.wSome);
    btnSave=(Button)findViewById(R.id.btnsave);
    btnClear=(Button)findViewById(R.id.btnclear);
    btnChange=(Button)findViewById(R.id.btnImg);
    radLaki=(RadioButton)findViewById(R.id.rbl);
    radPerempuan=(RadioButton)findViewById(R.id.rbp);
    chbSekolah=(CheckBox)findViewById(R.id.cbs);
    chbRumah=(CheckBox)findViewById(R.id.cbr);
    tvDateRes=(EditText)findViewById(R.id.tvDate);
    btnPick=(Button)findViewById(R.id.btnTime);
    ivImage=(ImageView)findViewById(R.id.Img);
    Button btnTime = (Button)findViewById(R.id.btnTime);

    //Then try your codes...