当前位置：首页 > news >正文

View-＞LinearLayout中动态添加多行多列的ItemView(来源RecyclerView中的ViewHodler)

news 来源：原创 2024/9/20 9:44:11

`XML`文件

ItemView布局R.layout.layout_item_view

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="wrap_content"android:layout_height="wrap_content"><FrameLayoutandroid:id="@+id/fl"android:layout_width="46dp"android:layout_height="46dp"android:background="@drawable/shape_dmt_bg"android:layout_margin="3dp"><ImageViewandroid:id="@+id/iv"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center"/></FrameLayout>
</FrameLayout>

Activity布局R.layout.activity_main

<?xml version="1.0" encoding="utf-8"?>
<FrameLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:background="@android:color/holo_red_light"><LinearLayoutandroid:id="@+id/list"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="20dp"android:paddingLeft="22dp"android:paddingRight="22dp"android:background="@color/black"android:orientation="vertical"></LinearLayout>
</FrameLayout>

`RecyclerView`的相关类

ViewHolder代码

class MyViewHolder(itemView: View, private val mListener: OnItemSelectListener?) : RecyclerView.ViewHolder(itemView) , MyListViewHelper.ISelectable {private var mIv: ImageView? = nullprivate var mFl: FrameLayout? = nullfun bind(index: Int, type: MyType) {mIv = itemView.findViewById(R.id.iv)mFl = itemView.findViewById(R.id.fl)mIv?.setImageResource(type.icon)itemView.setOnClickListener {mListener?.onItemSelect(index, type)}}override fun select() {mFl?.setBackgroundResource(R.drawable.shape_dmt_bg_on)mIv?.setColorFilter(Color.parseColor("#FFFFD800"))}override fun unselect() {mFl?.setBackgroundResource(R.drawable.shape_dmt_bg)mIv?.colorFilter = null}interface OnItemSelectListener {fun onItemSelect(index: Int, type: MyType)}
}data class MyType (val icon: Int, val type: TYPE) {enum class TYPE {A, B, C,}
}

Adapter代码

class MyAdapter : RecyclerView.Adapter<MyViewHolder>() {private val mData = ArrayList<MyType>().apply {add(MyType(R.drawable.ic_rect, MyType.TYPE.A))add(MyType(R.drawable.ic_crop_free, MyType.TYPE.B))add(MyType(R.drawable.ic_icon_crop_rotate, MyType.TYPE.C))add(MyType(R.drawable.ic_rect, MyType.TYPE.A))add(MyType(R.drawable.ic_crop_free, MyType.TYPE.B))add(MyType(R.drawable.ic_icon_crop_rotate, MyType.TYPE.C))add(MyType(R.drawable.ic_rect, MyType.TYPE.A))add(MyType(R.drawable.ic_crop_free, MyType.TYPE.B))add(MyType(R.drawable.ic_icon_crop_rotate, MyType.TYPE.C))add(MyType(R.drawable.ic_crop_free, MyType.TYPE.B))add(MyType(R.drawable.ic_icon_crop_rotate, MyType.TYPE.C))}private var mSelectedListener: MyViewHolder.OnItemSelectListener? = nullfun setOnItemSelectListener(listener: MyViewHolder.OnItemSelectListener) {mSelectedListener = listener}override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {val itemView = LayoutInflater.from(parent.context).inflate(R.layout.layout_item_view, parent, false)return MyViewHolder(itemView, mSelectedListener)}override fun onBindViewHolder(holder: MyViewHolder, position: Int) {holder.bind(position, mData[position])}override fun getItemCount(): Int {return mData.size}
}

动态添加`ItemView`的工具类

传入RecyclerView的Adapter，在父View中动态添加RecyclerView的每个ItemView(依次调用Adapter的onCreateViewHolder方法和onBindViewHolder方法)

class MyListViewHelper(private val mContext : Context, private val mColumns : Int = 5, private val mMarginBottom : Float = 20f) {private val mViews = HashMap<Int, RecyclerView.ViewHolder>()private var mSelectedIndex = -1fun <T : RecyclerView.ViewHolder> setAdapter(parentView: ViewGroup, adapter: RecyclerView.Adapter<T>){// 确定要添加的行数val rows = Math.ceil(((adapter.itemCount / (mColumns * 1f)).toDouble())).toInt() // 向上取整，确定最大行数Log.d("yang", "adapter.itemCount = ${adapter.itemCount}, rows = $rows")for (row in 0 until rows) {val childLinearLayout = LinearLayout(parentView.context).apply {orientation = LinearLayout.HORIZONTAL}val params = ViewGroup.MarginLayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT).apply {bottomMargin = dpToPx(mContext, mMarginBottom).toInt()}// 每一行的Linearlayout开始添加ItemViewfor (column in 0 until mColumns) {val index = row * mColumns + columnval viewHolder: RecyclerView.ViewHolderif (index < adapter.itemCount) {viewHolder = adapter.createViewHolder(childLinearLayout, adapter.getItemViewType(index))adapter.bindViewHolder(viewHolder, index)mViews[index] = viewHolder} else {// 如果不足一行，补充空白的占位ItemViewviewHolder = adapter.createViewHolder(childLinearLayout, 0)viewHolder.itemView.visibility = View.INVISIBLE}val itemViewParams = LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT).apply {leftMargin = 50rightMargin = 50}childLinearLayout.addView(viewHolder.itemView, itemViewParams)}// 添加到父布局的LinearLayout中childLinearLayout.gravity = Gravity.CENTER_HORIZONTALparentView.addView(childLinearLayout, params)}}fun performSelect(index: Int) {if (index == mSelectedIndex) {return}val vh = mViews[index] ?: returnvh.itemView.performClick()}fun select(index: Int) {if (index == mSelectedIndex) {return}val vh = mViews[index] ?: returnval oldVH = mViews[mSelectedIndex](oldVH as ISelectable?)?.unselect()(vh as ISelectable).select()mSelectedIndex = index}interface ISelectable {fun select()fun unselect()}
}

`Activity`代码

class MainActivity : AppCompatActivity() {private lateinit var mList: ViewGroupprivate lateinit var mListHelper: MyListViewHelperprivate lateinit var mAdapter : MyAdapteroverride fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)mList = findViewById(R.id.list)mAdapter = MyAdapter()mAdapter.setOnItemSelectListener(object : MyViewHolder.OnItemSelectListener {override fun onItemSelect(index: Int, type: MyType) {mListHelper.select(index)}})mListHelper = MyListViewHelper(this, 3)mListHelper.setAdapter(mList, mAdapter)mListHelper.performSelect(0)}
}