调整和定位 RecyclerView 项目

Question

我正在使用 RecyclerView 在网格布局中显示项目。下面是模拟器的图像和我需要实现的期望结果。左侧（执行）图像是我模拟器上的输出，而右侧（期望）是我想要实现的输出。

Activity布局XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/parentLayout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="#d3c3c3">

 <include
    android:id="@+id/toolBarIncluded"
    layout="@layout/toolbar_new_layout" />


<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_below="@+id/toolBarIncluded"
    android:orientation="vertical"
    android:weightSum="1">

    <RelativeLayout

        android:id="@+id/recyclerAdView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="10dp"
        android:layout_weight="0.65"
        android:background="#009688" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/recyclerAdView"
        android:layout_gravity="center"
        android:layout_weight="0.35"
        android:background="#00000000"
        android:gravity="center">

        <android.support.v7.widget.RecyclerView

            android:id="@+id/recyclerGridView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:background="#00000000"
            android:foregroundGravity="center" />

    </RelativeLayout>

</LinearLayout>

列表项XML

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/llGridItemLayout"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center"
 android:layout_margin="6dp"
 android:background="@drawable/drawable_grid_item_background"
 android:gravity="center"
 android:paddingStart="2dp"
 android:paddingEnd="2dp"
 android:orientation="vertical">

 <ImageView
    android:id="@+id/ivItemIcon"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scaleType="fitCenter"
    android:src="@drawable/ic_new_receipt_wrong" />

  <TextView
    android:layout_marginTop="6dp"
    android:id="@+id/tvItemName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:lines="1"
    android:text="My Complaints"
    android:textSize="14sp" />

 </LinearLayout>

Activity 代码段

    gridLayoutManager = new GridLayoutManager(MainActivity.this, 3);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(gridLayoutManager);
    recyclerView.setAdapter(demoDashAdapter);

适配器代码片段

int viewHeight ,viewWidth ;
public onCreateViewHolder(){
   viewHeight = viewGroup.getMeasuredHeight() / 4;
   viewWidth = viewGroup.getMeasuredWidth() / 3;
  ...
}

public onBindViewHolder(){

  viewHolder.itemLayout.setMinimumWidth(viewWidth);
  viewHolder.itemLayout.setMinimumHeight(viewHeight);
  ...
}

因此我的问题是，如何动态调整 recyclerView 中项目的大小。请注意，我使用的布局权重为 0.65 和 0.35 而不是 weightSum 1;

请指导我。

Answer 1

您可以尝试在 onCreateViewHolder 中为此使用 LayoutParams，如下所示：

  public Holder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View rowLayout = LayoutInflater.from(context).inflate(R.layout.row, parent, false);
    ViewGroup.LayoutParams layoutParams = rowLayout.getLayoutParams();
    layoutParams.height = (int) (parent.getHeight() * 0.15); // control the recyclerView row height from here
    rowLayout.setLayoutParams(layoutParams);
    return new Holder(rowLayout);
}

Answer 2

为什么 viewHeight = viewGroup.getMeasuredHeight() / 4？

如果要显示 3 行，只需除以 3。还要考虑 item.xml

中的边距

因此获取一行中每个项目的高度应该类似于：

(viewGroup.getMeasuredHeight()/3) - (marginTop + marginBot)

Answer 3

不要使用 RecyclerView.Adapter 来改变视图的布局方式。这是 RecyclerView.LayoutManager 的责任。

您可以覆盖方法验证 View.LayoutParams 以均匀分配大小：

 //customized GridLayoutManager
 gridLayoutManager = new GridLayoutManager(MainActivity.this, 3){
     @Override
     public boolean checkLayoutParams(RecyclerView.LayoutParams lp) {
         // force size of viewHolder here, this will override layout_height and layout_width from xml
         lp.height = getHeight() / getSpanCount();
         lp.width = getWidth() / getSpanCount();
         return true;
     }
 };
 recyclerView.setHasFixedSize(true);
 recyclerView.setLayoutManager(gridLayoutManager);

调整和定位 RecyclerView 项目

Resizing and positioning RecyclerView items

android

grid-layout

gridlayoutmanager

android-recyclerview

recyclerview-layout