Question

我将RecyclerView定义为网格，方法是将其布局设置为GridLayoutManger，其跨度为3，已经正常工作。我还在我的Recycler视图中添加了一个项目装饰器，它将管理网格项之间的间距，这也可以。

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {

    private int spanCount;
    private int spacing;
    private boolean includeEdge;

    public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
        this.spanCount = spanCount;
        this.spacing = spacing;
        this.includeEdge = includeEdge;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int position = parent.getChildAdapterPosition(view); // item position
        int column = position % spanCount; // item column

        if (includeEdge) {
            outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
            outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)

            if (position < spanCount) { // top edge
                outRect.top = spacing;
            }
            outRect.bottom = spacing; // item bottom
        } else {
            outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
            outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f /    spanCount) * spacing)
            if (position >= spanCount) {
                outRect.top = spacing; // item top
            }
        }
    }
}

我将项目装饰添加到我的Recycler View的实现：

mBuddiesGrid = (RecyclerView) findViewById(R.id.buddies_grid);
        mLayoutManager = new GridLayoutManager(getApplicationContext(), 3);
        mBuddiesGrid.addItemDecoration(new GridSpacingItemDecoration(3, (int) dpToPx(10) , true));
        mBuddiesAdapter = new BuddiesGridAdapter(getApplicationContext(), new Buddies());
        mBuddiesGrid.setLayoutManager(mLayoutManager);

我的网格项xml布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <ImageView
        android:layout_weight="1"
        android:cropToPadding="false"
        android:id="@+id/profile_picture"
        android:scaleType="centerCrop"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <TextView
        android:text="Theodore"
        android:includeFontPadding="false"
        android:textColor="@android:color/black"
        android:id="@+id/name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

通过在网格项之间添加空格将调整网格项的宽度，这可能导致无法获得项目视图的比例大小。我想要获得的是动态调整我的网格项高度等于其宽度。我该怎么办？

Answer 1

您可以确保相等宽度/高度的一种方法是使用自定义视图，该视图根据调用onMeasure()时的宽度计算高度。这样做的好处是，除了创建自定义视图之外，不涉及编码。

这是一个扩展LinearLayout的自定义视图：

public class SquareLayout extends LinearLayout {

    public SquareLayout(Context context) {
        super(context);
    }

    public SquareLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public SquareLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int width, int height) {
        // note we are applying the width value as the height
        super.onMeasure(width, width);
    }

}

以下是使用上述自定义LinearLayout：

的网格项布局的更改版本

<com.yourpackage.name.views.SquareLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/profile_picture"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:cropToPadding="false"
        android:scaleType="centerCrop" />

    <TextView
        android:id="@+id/name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:includeFontPadding="false"
        android:textColor="@android:color/black"
        android:text="Theodore"/>

</com.yourpackage.name.views.SquareLayout>

Answer 2

我已经使用ConstraintLayout完成了此操作：

<android.support.constraint.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:layout_width="match_parent"
    android:layout_height="wrap_content"
    >

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintDimensionRatio="1:1"
        tools:src="@drawable/ic_chat_bubble_black_24dp"
        />

</android.support.constraint.ConstraintLayout>

Answer 3

您可以在＆＃34; onBindViewHolder＆＃34;中编写代码。在回收者视图持有人中的功能。在那里你可以获得回收者视图的视图树观察者并改变回收者项目视图的宽度或（和）高度。

如何使RecyclerView的网格项具有相同的高度和宽度？

3 个答案: