无法在 MainActivity(child) 中查看在 BaseActivity(parent) 中创建的 progressBar？

Question

我正在尝试为所有冗余操作创建一个基础 activity。我尝试将进度条放在 BaseActivity 中并尝试在 MainActivity 中扩展它，但它根本没有显示出来。我的代码

activity_base.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/activity_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent">


    </FrameLayout>

    <ProgressBar
        android:id="@+id/progressBar"
        android:indeterminate="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

BaseActivity.java

public abstract class BaseActivity extends AppCompatActivity {

    private static final String TAG = "BaseActivity";

    public ProgressBar progressBar;

    @Override
    public void setContentView(int layoutResID) {

        ConstraintLayout constraintLayout = (ConstraintLayout) getLayoutInflater().inflate(R.layout.activity_base, null);
        FrameLayout frameLayout = constraintLayout.findViewById(R.id.activity_content);
        progressBar = constraintLayout.findViewById(R.id.progressBar);
        Log.i(TAG, "setContentView: Progressbar" + progressBar.getVisibility());

        getLayoutInflater().inflate(layoutResID, frameLayout, true);
        super.setContentView(layoutResID);
    }

    public void showProgressBar(boolean visibility) {
        progressBar.setVisibility(visibility ? View.VISIBLE : View.GONE);
    }
}

MainActivity.java


public class MainActivity extends BaseActivity {

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_get_data = (Button) findViewById(R.id.btn_get_data);

        btn_get_data.setOnClickListener(view -> {


       if (progressBar.getVisibility() == View.VISIBLE) {
                Log.i(TAG, "onCreate: DISABLING PROGRESS BAR");
                showProgressBar(false);
            } else {
                showProgressBar(true);
            }

   }


}

app里面还有其他东西，但是跟进度条没有关系。是的，我已经正确地声明了按钮和其他东西。

提前致谢！

Answer 1

改变

super.setContentView(layoutResID);

至

super.setContentView(constraintLayout);

在 BaseActivity 的 setContentView() 方法中。

无法在 MainActivity(child) 中查看在 BaseActivity(parent) 中创建的 progressBar？

Cannot view progressBar created in BaseActivity(parent) in MainActivity(child)?

java

android

android-progressbar