recycleview实现gridview网格

说明：

kotlin语言，用recycleview实现gridview效果，监听点击item，回调

效果图：

step1:

package com.example.flushfragmentdemo

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import androidx.recyclerview.widget.GridLayoutManager
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {
    private lateinit var courseAdapter: CourseAdapter
    private val courseList = listOf(
        Course(R.mipmap.ic_launcher, "Android + Java + Firebase"),
        Course(R.mipmap.ic_launcher, "Java Foundations"),
        Course(R.mipmap.ic_launcher, "Android"),
        Course(R.mipmap.ic_launcher, "Firebase")
    )

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        courseAdapter = CourseAdapter(courseList) { course, position ->
           Log.e("TAG","click:"+position)
        }
        rvLanguage.layoutManager = GridLayoutManager(this, 3) // 2 columns
        rvLanguage.adapter = courseAdapter
    }
}

step2:

package com.example.flushfragmentdemo


import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView

class CourseAdapter(
    private val courseList: List<Course>,
    private val clickListener: (Course, Int) -> Unit // Add this parameter
) : RecyclerView.Adapter<CourseAdapter.CourseViewHolder>() {

    // ViewHolder class that binds the views
    class CourseViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val courseImage: ImageView = itemView.findViewById(R.id.courseImage)
        val courseText: TextView = itemView.findViewById(R.id.courseText)
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CourseViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_course, parent, false)
        return CourseViewHolder(view)
    }

    override fun onBindViewHolder(holder: CourseViewHolder, position: Int) {
        val course = courseList[position]
        holder.courseImage.setImageResource(course.imageResId)
        holder.courseText.text = course.name

        // Set a click listener on the itemView (the entire item)
        holder.itemView.setOnClickListener {
            clickListener(course, position) // Call the passed in listener
        }
    }

    override fun getItemCount(): Int {
        return courseList.size
    }
}

step3:

package com.example.flushfragmentdemo


data class Course(val imageResId: Int, val name: String)

step4:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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="match_parent"
    android:layout_margin="8dp">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rvLanguage"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

step5:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:layout_margin="4dp"
    android:background="@android:color/holo_red_dark"
    android:padding="8dp">

    <!-- Course Image -->
    <ImageView
        android:id="@+id/courseImage"
        android:layout_width="100dp"
        android:layout_height="100dp"


        android:scaleType="center"
        android:src="@mipmap/ic_launcher" />

    <!-- Course Text -->
    <TextView

        android:id="@+id/courseText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="8dp"
        android:paddingBottom="4dp"
        android:gravity="left"
        android:text="Course Name"
        android:textSize="12sp"
        android:textColor="@color/black" />

    <!-- Grey Divider -->
    <View
        android:layout_width="match_parent"
        android:layout_height="6dp"
        android:background="@android:color/holo_green_dark"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp" />

</LinearLayout>

end