java.lang.IllegalStateException : Could not find method in a parent or ancestor Context for android:onClick attribute 错误

Question

我正在尝试将 onClick 方法 front() 添加到我的 Button。但是，当我单击按钮时，它会返回此错误:

java.lang.IllegalStateException: Could not find method front(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'front'

这是我的 xml:

<Button
    android:id="@+id/front"
    android:onClick="front"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Text" />

注册.java:

public class Register extends AppCompatActivity {

    private Button front;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);

        front = (Button) findViewById(R.id.front);
    }

    private void front(View v) {
        Toast.makeText(Register.this, "String", Toast.LENGTH_LONG).show();
    }

}

知道问题出在哪里吗？

Answer 1

一定要正确书写属性值onClick的语法。就我而言，我忘记了字符 }

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:clickable="true"
    android:focusable="true"
    android:onClick="@{() -> viewModel.onItemClick(position)}">

GL