android - 升高的 RecyclerView 项目逐渐变形(海拔变化)

Question

知道为什么 RecyclerView 项目会变形，每个连续的项目都会变得更糟吗？

更新:我正在使用 CardViews，现在没有 View “变形”，但阴影/海拔高度发生了变化。

似乎高度会随着项目在屏幕上的垂直位置而变高，阴影会随着项目向下滚动而增加。请在此处观看视频:https://youtu.be/nROYq8rpUMs .

我建立了一个新项目，只留下演示问题所需的代码:

主 Activity .java

package tzig.schm00.masterdetail;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


import tzig.schm00.masterdetail.dummy.DummyContent;

import java.util.List;

public class MainActivity extends AppCompatActivity {

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

        View recyclerView = findViewById(R.id.item_list);
        setupRecyclerView((RecyclerView) recyclerView);

    }

    private void setupRecyclerView(@NonNull RecyclerView recyclerView) {
        recyclerView.setAdapter(new SimpleItemRecyclerViewAdapter(DummyContent.ITEMS));
    }

    public class SimpleItemRecyclerViewAdapter
            extends RecyclerView.Adapter<SimpleItemRecyclerViewAdapter.ViewHolder> {

        private final List<DummyContent.DummyItem> mValues;

        public SimpleItemRecyclerViewAdapter(List<DummyContent.DummyItem> items) {
            mValues = items;
        }

        @Override
        public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.list_item, parent, false);
            return new ViewHolder(view);
        }

        @Override
        public void onBindViewHolder(final ViewHolder holder, int position) {
            holder.mItem = mValues.get(position);
            holder.mIdView.setText(mValues.get(position).id);
            holder.mContentView.setText(mValues.get(position).content);
        }

        @Override
        public int getItemCount() {
            return mValues.size();
        }

        public class ViewHolder extends RecyclerView.ViewHolder {
            public final View mView;
            public final TextView mIdView;
            public final TextView mContentView;
            public DummyContent.DummyItem mItem;

            public ViewHolder(View view) {
                super(view);
                mView = view;
                mIdView = (TextView) view.findViewById(R.id.id);
                mContentView = (TextView) view.findViewById(R.id.content);
            }

            @Override
            public String toString() {
                return super.toString() + " '" + mContentView.getText() + "'";
            }
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    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/frameLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/item_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        app:layoutManager="LinearLayoutManager"
        tools:context="tzig.schm00.myapplication.MainActivity" />

</FrameLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/cont_item_root"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    card_view:cardCornerRadius="8dp"
    card_view:cardElevation="10dp"
    card_view:cardMaxElevation="10dp"
    card_view:cardUseCompatPadding="true">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="@dimen/text_margin"
            android:textAppearance="?attr/textAppearanceListItem" />

        <TextView
            android:id="@+id/content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="@dimen/text_margin"
            android:textAppearance="?attr/textAppearanceListItem" />
    </LinearLayout>

</android.support.v7.widget.CardView>

新观察:这似乎是一种标准行为。与使用 CardViews 显示文件夹的图像选择器看起来一样...

非常感谢任何帮助!

谢谢!!

Answer 1

这就是根据 Material Design: Environment: Light and shadows: Light 设计的样子.

另见答案 https://stackoverflow.com/a/51216164/6685260