如何让RecyclerView中的项自动适应Android屏幕宽度？

Question

我想实现以下布局，希望将项目放置在屏幕的整个宽度上：

期望的布局: 实际布局:

这是我的RecyclerView项目的代码：

<?xml version="1.0" encoding="utf-8"?>
<layout 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">

  <androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingTop="@dimen/size_8dp"
    android:paddingStart="@dimen/size_20dp"
    android:paddingEnd="@dimen/size_20dp"
    android:paddingBottom="@dimen/size_8dp">

    <ImageView
      android:id="@+id/legendsItemIcon"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      app:layout_constraintTop_toTopOf="parent"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintBottom_toTopOf="@+id/text_legend_status_name"
      />
    <TextView
      android:id="@+id/text_legend_status_name"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      tools:text="Low"
      android:textSize="@dimen/text_size_8sp"
      app:layout_constraintTop_toBottomOf="@+id/legendsItemIcon"
      app:layout_constraintStart_toStartOf="@+id/legendsItemIcon"
      app:layout_constraintEnd_toEndOf="@+id/legendsItemIcon"
      app:layout_constraintBottom_toBottomOf="parent"
      android:textColor="@color/legends_item_status_text_color"
      android:layout_marginTop="@dimen/size_4dp"
      />

  </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

我该如何实现这个目标？

- sagar suri

---

你的RecyclerView是水平方向吗？ - Dhaval Solanki

它可以有更多的内容 @nicej - sagar suri

我有一个子RecyclerView在父RecyclerView中。 - sagar suri

一行可以有多少个项目？它是否可滚动？ - ahsanali274

是的，它是可滚动的 @user10284284 - sagar suri

Answer 1

这个自定义类将帮助你 https://gist.github.com/heinrichreimer/39f9d2f9023a184d96f8

import android.content.Context;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.ViewGroup;

public class SpanningLinearLayoutManager extends LinearLayoutManager {

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

public SpanningLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
    super(context, orientation, reverseLayout);
}

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

@Override
public RecyclerView.LayoutParams generateDefaultLayoutParams() {
    return spanLayoutSize(super.generateDefaultLayoutParams());
}

@Override
public RecyclerView.LayoutParams generateLayoutParams(Context c, AttributeSet attrs) {
    return spanLayoutSize(super.generateLayoutParams(c, attrs));
}

@Override
public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) {
    return spanLayoutSize(super.generateLayoutParams(lp));
}

@Override
public boolean checkLayoutParams(RecyclerView.LayoutParams lp) {
    return super.checkLayoutParams(lp);
}

private RecyclerView.LayoutParams spanLayoutSize(RecyclerView.LayoutParams layoutParams){
    if(getOrientation() == HORIZONTAL){
        layoutParams.width = (int) Math.round(getHorizontalSpace() / (double) getItemCount());
    }
    else if(getOrientation() == VERTICAL){
        layoutParams.height = (int) Math.round(getVerticalSpace() /  (double) getItemCount());
    }
    return layoutParams;
}

@Override
public boolean canScrollVertically() {
    return false;
}
@Override
public boolean canScrollHorizontally() {
    return false;
}

private int getHorizontalSpace() {
    return getWidth() - getPaddingRight() - getPaddingLeft();
}

private int getVerticalSpace() {
    return getHeight() - getPaddingBottom() - getPaddingTop();
}
}

将RecyclerView的布局管理器设置为SpanningLinearLayoutManager，而不是LinearLayoutManager。

- SSB

---

足够接近了。我如何均匀分配这些项目并使内容可滚动？我有超过10个项目，它们会非常接近。@SSB - sagar suri

@SSB，你能看一下这个问题吗？ - Kotlin Learner

像魔法一样好用。 - hetsgandhi

Answer 2

如果你想让Recyclerview包裹其内容（完全高度拉伸包裹其内容）。只需用NestedScrollView将其包装起来即可。我测试过，它可以工作。

<androidx.core.widget.NestedScrollView
  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="wrap_content"
  >

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    >

    <!-- This Recyclerview will fit content.
    So it become full height stretch wrap its content-->
    <RecyclerView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="Bayar SPP"
        style="@style/FontStyleSubtitle"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/recyclerView" />

   </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.core.widget.NestedScrollView>

- Jetwiz

Answer 3

请使用以下代码：

recyclerView.layoutManager = GridLayoutManager(context, splitcount)

这对我有用。

- vidhya chinnusamy

Answer 4

如果我理解正确，您需要一个水平的可循环视图。因此，请将您的布局管理器设置如下：

    LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this);
    linearLayoutManager.setOrientation(RecyclerView.HORIZONTAL);
    recyclerView.setLayoutManager(mHorizontalLayoutManager);

如果您的项目超过了屏幕尺寸，它将会是可滚动的。

- Anice Jahanjoo

---

嗨，你能看一下这个问题吗？ - Kotlin Learner

Answer 5

您只需使用GridLayoutManager而不是LinearLayoutManager。

 /**
 * Creates a vertical GridLayoutManager
 *
 * @param context Current context, will be used to access resources.
 * @param spanCount The number of columns in the grid
 */
public GridLayoutManager(Context context, int spanCount) {
    super(context);
    setSpanCount(spanCount);
}

- khoiln218