导航时Android应用程序停止

Question

I am new to android, my app fails or stops working when I click the navigate button which should direct me to another activity. This is my code to navigate to the next activity.

public void checkout(View view) {
      Intent intent = new Intent(this, SelectedItemsControl.class);
      startActivity(intent);
}

My SelectedItemsControl.class code:

public class SelectedItemsControl extends AppCompatActivity {

    ListView lv2 ;
    ArrayList<String> CheckoutList ;
    ArrayAdapter adapter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.selecteditems);

lv2 =  (ListView) findViewById(R.id.listviewtwo);
        CheckoutList = new ArrayList<>();
        adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_2,CheckoutList);
lv2.setAdapter(adapter);

    }
}

Answer 1

Your code Should look like

public void checkout(View view){
    Intent intent = new Intent(FirstActivity.this, SecondActivity.class); // no space in class name
    startActivity(intent); }//no space between Start and Activity.

Answer 2

check manifest. Your activity is declared or not there

<activity android:name=".SelectedItemsControl" />

hope it helps you. If you have some different problem please ask me will help you, If this doesn't help try second option

public void checkout(View view){
    Intent intent = new Intent(FirstActivity.this, SecondActivity.class); 
    startActivity(intent); }

try to comment code in your second Activity. It helps if you have any error in second activity.

public class SelectedItemsControl extends AppCompatActivity {

    ListView lv2 ;
    ArrayList<String> CheckoutList ;
    ArrayAdapter adapter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.selecteditems);

/*lv2 =  (ListView) findViewById(R.id.listviewtwo);
        CheckoutList = new ArrayList<>();
        adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_2,CheckoutList);
lv2.setAdapter(adapter);*/

    }
}