我正在制作一个简单的应用程序，你输入你的名字，点击一个按钮，选择一个爱好，然后它会回到你的名字和爱好一起的主布局。当我单击“取消（取消）”按钮时遇到问题，应用程序不断收到致命错误。你觉得它可能是什么？
主要活动：
package com.example.holaamigos;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
public final static String EXTRA_SALUDO = "com.example.holaamigos.SALUDO";
TextView txtfinal;
String saludo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText txtNombre = (EditText)findViewById(R.id.TxtNombre);
final Button btnHola = (Button)findViewById(R.id.BtnHola);
final CheckBox checkbox1 =(CheckBox)findViewById(R.id.checkBox1);
txtfinal=(TextView)findViewById(R.id.textView1);
checkbox1.setOnCheckedChangeListener(new OnCheckedChangeListener(){
@Override
public void onCheckedChanged(CompoundButton arg0,
boolean checked) {
if (checked)
{
Toast.makeText(checkbox1.getContext(), "Activo", Toast.LENGTH_LONG).show();
btnHola.setVisibility(0);
btnHola.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, ActivitySaludo.class);
saludo = txtNombre.getText().toString();
intent.putExtra(EXTRA_SALUDO, saludo);
startActivityForResult(intent, 1);
}
});
}
else
{
Toast.makeText(checkbox1.getContext(), "Inactivo", Toast.LENGTH_SHORT).show();
btnHola.setVisibility(View.INVISIBLE);
}
}
});
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK);
String string= data.getStringExtra("HOBBY");
txtfinal.setText("Nombre:" + saludo + " " + "Hobby:" + string);
if (resultCode == RESULT_CANCELED){
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
活动Saludo：
package com.example.holaamigos;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;
public class ActivitySaludo extends Activity {
String myspinner;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_saludo);
Intent intent = getIntent();
String saludo = intent.getStringExtra(MainActivity.EXTRA_SALUDO);
TextView txtCambiado = (TextView) findViewById(R.id.TxtSaludo);
txtCambiado.setText(getString(R.string.hola_saludo) + " " + saludo);
final Spinner spinner = (Spinner)findViewById(R.id.SpinnerSaludo);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.hobby, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new OnItemSelectedListener () {
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int pos, long id) {
parent.getItemAtPosition(pos);
myspinner = spinner.getItemAtPosition(pos).toString();
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
//another call
}
});
final Button BtnAceptar=(Button) findViewById(R.id.buttonAceptar);
BtnAceptar.setOnClickListener(new OnClickListener (){
@Override
public void onClick(View v) {
Intent iboton = new Intent();
iboton.putExtra("HOBBY", myspinner);
setResult(RESULT_OK, iboton);
finish();
}
});
final Button BtnCancelar=(Button) findViewById(R.id.buttonCancelar);
BtnCancelar.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
Intent iboton2 = new Intent();
iboton2 = null;
setResult(RESULT_CANCELED, iboton2);
finish();
}
});
}
}