Question

我将ConstraintLayout用作父项，并将recyclerview放入其中以填充列表。假设我必须给项目计数5来填充列表并运行代码，然后列表显示完美，但是recyclerview的最后一项显示一半且不完全可见，并且滚动在此处停止。我发现一个解决方案是，如果将高度match_parent赋予recyclerview，则可以正常工作，但所有其他视图都隐藏在recyclerview后面。如果我使用另一个父视图（如LinearLayout或RelativeLayout），则高度为wrap_content的recyclerview效果很好，并且所有列表项都是完全可见的。

我尝试了两种对我有用的方法，但是我发现错误的编程习惯

我将高度match_parent赋予recyclerview，并将top_margin赋予recylerview，以便显示所有其他UI项目。
我将padding_bottom赋予recyclerview，直到所有列表项位置都可见

我的XML文件“ activity_per_day_sale.xml”在下面。

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
        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="match_parent"
        android:background="@color/black">


    <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_constraintStart_toStartOf="parent"

            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:popupTheme="@style/AppTheme.PopupOverlay">
        <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center_vertical">
            <ImageView
                    android:layout_width="40dp"
                    android:layout_height="40dp"
                    android:id="@+id/btn_back"
                    android:padding="5dp"
                    android:onClick="OnClickPerDaySale"
                    android:background="?attr/selectableItemBackground"
                    android:src="@drawable/icon_back_white"
            />

            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="Signup"
                      android:layout_centerInParent="true"
                      android:id="@+id/home_title_text"
                      android:textColor="@color/black"
                      android:visibility="gone"
                      android:fontFamily="@font/seguisb"
                      android:textSize="18sp"/>

            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="SKIP"

                      android:padding="10dp"
                      android:layout_centerVertical="true"
                      android:visibility="gone"
                      android:id="@+id/skip"
                      android:textColor="@color/black"
                      android:fontFamily="@font/seguisb"
                      android:textSize="18sp"/>

        </RelativeLayout>
    </android.support.v7.widget.Toolbar>
    <TextView android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:textSize="25sp"
              android:layout_marginTop="10dp"
              android:text="Per Day Sale Details"
              android:textColor="@color/yellow_app_logo_color"
              android:fontFamily="@font/segoeuib"
              app:layout_constraintTop_toBottomOf="@+id/toolbar"
              app:layout_constraintStart_toStartOf="parent"
              android:id="@+id/TV_signupScreenText"
              android:layout_marginLeft="45dp"/>

        <android.support.v7.widget.RecyclerView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/rv_perday_sale"
                android:layout_marginTop="10dp"
                android:layout_marginHorizontal="10dp"
                app:layout_constraintTop_toBottomOf="@+id/TV_signupScreenText"/>

</android.support.constraint.ConstraintLayout>

活动类别为“ PerDaySaleActivity.kt”

import android.content.Context
import android.content.Intent
import android.os.Bundle
import android.support.v7.widget.StaggeredGridLayoutManager
import android.view.View
import com.nq.NQManager.R
import com.nq.NQManager.utils.BaseActivity
import kotlinx.android.synthetic.main.activity_per_day_sale.*

class PerDaySaleActivity:BaseActivity(){
    var adapterPerdaySale : AdapterPerdaySale? = null

    companion object {
        fun start(context: Context) {
            val starter = Intent(context, PerDaySaleActivity::class.java)
            context.startActivity(starter)
        }
    }
    override fun getID(): Int {
        return R.layout.activity_per_day_sale
    }

    override fun iniView(savedInstanceState: Bundle?) {
        initViews()
    }
    fun OnClickPerDaySale(v: View){
        when(v){
            btn_back->{
                finish()
            }
        }
    }
    fun initViews() {
        adapterPerdaySale   = AdapterPerdaySale( this)
        rv_perday_sale.layoutManager = StaggeredGridLayoutManager(1, 1)
        rv_perday_sale.adapter = adapterPerdaySale
    }

    private fun setUpRecyclerView() {
        runOnUiThread { adapterPerdaySale!!.notifyDataSetChanged() }

    }

我的适配器类“ AdapterPerdaySale.kt”

mport android.content.Context
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import com.nq.NQManager.R
import kotlinx.android.synthetic.main.adapter_perday_sale.view.*

class AdapterPerdaySale(context: Context):
    RecyclerView.Adapter<AdapterPerdaySale.MyViewHOlder>()  {

        private var ctx:Context?=context


        override fun onCreateViewHolder(p0: ViewGroup, p1: Int): MyViewHOlder {
            return MyViewHOlder(LayoutInflater.from(ctx).inflate(R.layout.adapter_perday_sale, p0, false))
        }

        override fun getItemCount(): Int {
            return 5
        }

        override fun onBindViewHolder(holder: MyViewHOlder, position: Int) {
            if (position==1){
                holder.tv_date.text="26 June, 2019"
            }else if(position==2){
                holder.tv_date.text="27 June, 2019"

            }
        }

        inner class MyViewHOlder(view: View) : RecyclerView.ViewHolder(view) {
            val tv_date=view.tv_date
        }
    }

我的适配器xml文件“ adapter_perday_sale.xml”

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
        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"
        android:paddingVertical="5dp"
android:background="@color/black">
    <TextView
            android:id="@+id/tv_date"
            android:layout_below="@+id/txt_today"
            android:layout_centerHorizontal="true"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@color/white"
            android:fontFamily="@font/segoeuib"
            android:text="25 June, 2019"
            android:textSize="23sp"
            android:layout_marginEnd="8dp" app:layout_constraintEnd_toEndOf="parent"
            android:layout_marginRight="8dp" android:layout_marginStart="8dp"
            app:layout_constraintStart_toStartOf="parent"
            android:layout_marginLeft="8dp" android:layout_marginTop="8dp"
            app:layout_constraintTop_toTopOf="parent"/>

    <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/linearLayout1"
            android:orientation="horizontal"
            app:layout_constraintTop_toBottomOf="@+id/tv_date">

        <LinearLayout
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_gravity="center"
                android:gravity="center"
                android:layout_height="wrap_content"
                android:orientation="vertical">
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:textSize="25sp"
                      android:layout_marginTop="5dp"
                      android:text="Orders"
                      android:layout_centerHorizontal="true"
                      android:textColor="@color/white"
                      android:fontFamily="@font/segoeuib"/>
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:textSize="50sp"
                      android:layout_marginTop="0dp"
                      android:text="50"
                      android:layout_centerHorizontal="true"
                      android:textColor="@color/order_history_txt_color"
                      android:fontFamily="@font/segoeui"/>
        </LinearLayout>
        <LinearLayout
                android:layout_width="0dp"
                android:layout_weight="1"
                android:gravity="center"
                android:layout_height="wrap_content"
                android:orientation="vertical">
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:textSize="25sp"
                      android:layout_marginTop="5dp"
                      android:text="Revenue"
                      android:layout_centerHorizontal="true"
                      android:textColor="@color/white"
                      android:fontFamily="@font/segoeuib"/>
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:textSize="50sp"
                      android:layout_marginTop="0dp"
                      android:text="£550"
                      android:layout_centerHorizontal="true"
                      android:textColor="@color/order_history_txt_color"
                      android:fontFamily="@font/segoeui"/>
        </LinearLayout>

    </LinearLayout>
    <View android:layout_width="match_parent"
          android:layout_height="1.5dp"
          android:background="@color/gray"
          android:id="@+id/view_1"
          app:layout_constraintTop_toBottomOf="@+id/linearLayout1"
          android:layout_marginLeft="8dp"
          android:layout_marginTop="10dp"
          android:layout_marginBottom="10dp"
          app:layout_constraintStart_toStartOf="parent"
          android:layout_marginStart="8dp"/>

</android.support.constraint.ConstraintLayout>

Answer 1

将此app:layout_constraintBottom_toBottomOf="parent"属性添加到您的recyclerview

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:popupTheme="@style/AppTheme.PopupOverlay">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_vertical">

            <ImageView
                android:id="@+id/btn_back"
                android:layout_width="40dp"
                android:layout_height="40dp"
                android:background="?attr/selectableItemBackground"
                android:onClick="OnClickPerDaySale"
                android:padding="5dp"
                android:src="@drawable/ic_background" />

            <TextView
                android:id="@+id/home_title_text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="Signup"
                android:textColor="#000"
                android:textSize="18sp"
                android:visibility="gone" />

            <TextView
                android:id="@+id/skip"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:layout_centerVertical="true"
                android:padding="10dp"
                android:text="SKIP"
                android:textColor="#000"
                android:textSize="18sp"
                android:visibility="gone" />

        </RelativeLayout>
    </androidx.appcompat.widget.Toolbar>

    <TextView
        android:id="@+id/TV_signupScreenText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="45dp"
        android:layout_marginTop="10dp"
        android:text="Per Day Sale Details"
        android:textColor="#AD4E4E"
        android:textSize="25sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/toolbar" />


    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv_perday_sale"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/TV_signupScreenText" />

</androidx.constraintlayout.widget.ConstraintLayout>

在ConstraintLayout中使用RecyclerView时，所有RecyclerView项都不可见

1 个答案: