android - 按下后退按钮时Android崩溃

Question

在 Activity (A)中，我将 Activity (B)与startActivityForResult(intent, 2)一起吃午餐，但是当我在 Activity (B)中按返回按钮时，应用程序崩溃。
Activity 代码(B)

.setOnItemClickListener(new OnItemClickListener(){
            @Override
            public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
                Deg f = dettagli.get(position);

                 Intent intent=new Intent();
                 intent.putExtra("value1", f.value1);
                 intent.putExtra("value2", f.value2);
                 setResult(2,intent);

                    finish();

            }
        });
        return row;

这是
LogCat java.lang.RuntimeException: Failure delivering result ResultInfo {who=null, request=2, result=0, data=null} to activity {Activity_o}: java.lang.NullPointerException

Answer 1

对象f为空，其他代码也可以!

if(f)
{

Intent intent=new Intent();

intent.putExtra("value1", f.value1);

intent.putExtra("value2", f.value2);

setResult(2,intent);

finish();
}