Android多个视图在添加scrollview时显示，但仅在移除scrollview并实现自定义滚动时才显示

如何解决Android多个视图在添加scrollview时显示，但仅在移除scrollview并实现自定义滚动时才显示

我已将片段添加到线性布局中，其中每个子片段视图都占据完整的屏幕。现在，我必须实现滚动功能，以便可以浏览它们。我试图添加一个scrollView（水平），它显示了所有的孩子，但由于某些问题，我无法使用scrollview。因此，要滚动，我使用了以下代码，该代码可以很好地滚动，但并未显示所有子项，即使滚动后也只有第一个可见：

/**
     * A function to scroll towards the left.
     */
    public void scrollLeft(){
        LinearLayout layout = findViewById(R.id.viewList);
        int x = getResources().getDisplayMetrics().widthPixels;
        layout.scrollBy(-x,0); // scroll by the amount of the screen's width
    }


    /**
     * A function to scroll towards the right.
     */
    public void scrollRight(){
        LinearLayout layout = findViewById(R.id.viewList);
        int x = getResources().getDisplayMetrics().widthPixels;
        layout.scrollBy(x,0); // scroll by the amount of the screen's width
        }

我什至尝试滚动ConstraintLayout（基本布局），但结果也相同。 这是我的activity_test.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"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/TestRoot"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".TestActivity">


    <LinearLayout
        android:id="@+id/viewList"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:baselineAligned="false"
        android:orientation="horizontal"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"></LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

这是我用来将片段添加到LinearLayout的代码，仅在onCreate方法中调用此代码：

FragmentManager manager = getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();

for (int i = 0; i < results.length; i++) {
    ResultFragment result = new ResultFragment();         
    // configuring the fragment
    // ....


    LinearLayout l = new LinearLayout(this);
    l.setId(View.generateViewId());
    transaction.add(l.getId(),result,"result-"+i);
    ((LinearLayout)findViewById(R.id.viewList)).addView(l,i);
    findViewById(R.id.viewList).invalidate();
}
transaction.commit();

解决方法

没有任何反应，但没有问题，我自己找到了解决方案。 所以我所做的很简单。我创建了一个自定义ScrollView，它重写了onTouchEvent函数，实现了自己的滚动机制，并将我的linearlayout放置在此scrollView和kaboom中！有效。新的ScrollView如下所示：

package com.nalin.test;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.HorizontalScrollView;


public class LockedHScrollView extends HorizontalScrollView {

    /** The variables used to detect left-right swipes*/
    float x1,x2;
    /** variable to check whether the swipes made were valid (distance was large enough) */
    final float distance = 200;



    public LockedHScrollView(Context context){super(context);}
    public LockedHScrollView(Context context,AttributeSet attrs){super(context,attrs);}
    public LockedHScrollView(Context context,AttributeSet attrs,int defStyleAttr){super(context,attrs,defStyleAttr);}


    /**
     * A function to scroll towards the left.
     */
    public void scrollLeft(){
        int x = getResources().getDisplayMetrics().widthPixels;
        scrollBy(-x,0); // scroll by the amount of the screen's width
    }


    /**
     * A function to scroll towards the right.
     */
    public void scrollRight(){
        int x = getResources().getDisplayMetrics().widthPixels;
        scrollBy(x,0); // scroll by the amount of the screen's width
    }


    /**
     * A function to check swipes for scrolling between multiple result fragments.
     */
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction()==MotionEvent.ACTION_DOWN){
            x1 = event.getX();
        }else if (event.getAction() == MotionEvent.ACTION_UP){
            x2 = event.getX();
            if ((x2-x1)>0){             //Right swipe
                if (x2-x1 >= distance){        // Validate that the swipe was long enough
                    scrollLeft();
                }
            }else if((x1-x2)>0){        // Left swipe
                if ((x1-x2)>=distance){        // Validate that the swipe was long enough
                    scrollRight();
                }
            }
        }
        return true;
    }
}