预期的错误类或接口，也是'}'预期。 [关闭]

Question

我对android很新。在简单的附加应用程序中，我收到错误。

public class MainActivity extends AppCompatActivity
 {

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

public void onButtonClick(View v)
{
    EditText e1 = (EditText)findViewById(R.id.editText);
    EditText e2 = (EditText)findViewById(R.id.editText2);
    TextView t1 = (TextView)findViewById(R.id.textView);
    int num1 = Integer.parseInt(e1.getText().toString());
    int num2 = Integer.parseInt(e2.getText().toString());
    int sum = num1 + num2 ;
    t1.setText(Integer.toString(sum));
}
}

Answer 1

在onCreate方法之后，你有括起}括号的类。你应该在onButtonClick方法之后移动它。

它应该是这样的：

public class MainActivity extends AppCompatActivity {

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

    public void onButtonClick(View v) {
          EditText e1 = (EditText)findViewById(R.id.editText);
          EditText e2 = (EditText)findViewById(R.id.editText2);
          TextView t1 = (TextView)findViewById(R.id.textView);
          int num1 = Integer.parseInt(e1.getText().toString());
          int num2 = Integer.parseInt(e2.getText().toString());
          int sum = num1 + num2 ;
          t1.setText(Integer.toString(sum));
    }
}