Why i got NullPointerException ?

Question

3.00/5 (2 votes)

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Code builded ok:

C#

Button buttonCancel = (Button)findViewById(R.id.Cancel);
try{
buttonCancel.setOnClickListener(buttonCancelOnClickListener);
}catch(Exception x)
{
    x.toString();//NullPointerException
}

In text_enter.xml:

HTML

<Button
    android:id="@+id/Cancel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/SendText"
    android:layout_alignBottom="@+id/SendText"
    android:layout_alignParentLeft="true"
    android:text="Cancel" />

buttonCancel = null, why? Please, help.

Posted 24-Nov-12 10:28am

halabella

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Comments

lewax00 25-Nov-12 0:59am

There's not enough information here to tell, but I'm guessing you are probably trying to get it before it's created. A little more context would help (if I'm right, then specifically which overridden method this is in or called from).

2 solutions

Solution 1

Though you not provide enough information but you can try like this..

Java

private Button buttonCancle;
@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.wishingpage);

    buttonCancel = (Button)findViewById(R.id.Cancel);

    buttonCancel.setOnClickListener(this);
    }

public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
    case R.id.buttonCancel:
             //do your button work here..you can add more button event using case
        break;
            }
    }

Posted 24-Nov-12 19:49pm

ridoy

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halabella · Accepted Answer · 2012-11-24T23:54:00

Solution 2

Solved. I had to

Java

setContentView(R.layout.text_enter);

that contains my Cancel button, before declaring and setting listener for it.

Posted 24-Nov-12 23:54pm

halabella