java - 即使已实现该方法，仍然出现错误 : 'implement abstract method ' onFocusChange(View, boolean )' in ' OnFocusChangeListener'

Question

我正在尝试在 EditText 上实现 OnFocusChangeListener。问题是我收到此错误

Class 'FacilityScreen' must either be declared abstract or implement abstract method 'onFocusChange(View, boolean)' in 'OnFocusChangeListener'

尽管 onFocusChange 方法已在 OnFocusChangeListener 中实现。

这是我的代码

 public class FacilityScreen extends AppCompatActivity implements AdapterView.OnItemSelectedListener,View.OnFocusChangeListener{

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

        EditText editText = (EditText) findViewById(R.id.enter_location);
        editText.setOnFocusChangeListener(new View.OnFocusChangeListener() {

            @Override
            public void onFocusChange(View view, boolean hasfocus) {
                if(hasfocus){
                     //do something
                }
            }
        });
    }
}

我错了什么？

Answer 1

您需要在 Activity 中使用 @Override public void onFocusChange() 方法

比这样使用 editText.setOnFocusChangeListener(this)

Check this example

public class FacilityScreen extends AppCompatActivity implements  View.OnFocusChangeListener{

    EditText editText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_facilty_screen);
        editText = (EditText) findViewById(R.id.enter_location);
        editText.setOnFocusChangeListener(this);

    }


    @Override
    public void onFocusChange(View view, boolean b) {
        if(view==editText){
            // perfom your action here
        }
    }
}