Table of contents
Second, the implementation of Grid
1. Define the split distance in item_recycler as 2dp
2. Modify the adapter HomeAdapter code:
1. The use of RecyclerView
The effect is as follows:
1. Configure build.gradle
As a result of the update of the dependent library, AndroidX completely replaces the support library, not only providing the same functionality, but also providing a new library. That is to say, the support-v7 library has been replaced. The specific configuration code is as follows:
implementation 'androidx.appcompat:appcompat:1.0.0'
implementation 'androidx.recyclerview:recyclerview:1.0.0'2. Use RecyclerView
The code is explained in the comments (if you don’t understand, you can send a private message), directly upload the code:
RecycleTestActivity：
public class RecycleTestActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private HomeAdapter myHomeAdapter;
private List<String> mList = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recycler_test);
InitView();
useRecycleView();//使用RecyclerView
setListener();//设置监听事件
}
//初始化控件
private void InitView() {
recyclerView = (RecyclerView) this.findViewById(R.id.id_recyclerview);
for (int i = 0; i < 20; i++) {
mList.add(i + "");
}
}
//使用RecyclerView布局管理
public void useRecycleView(){
//设置布局管理器
/**
* new LinearLayoutManager(this)指的是默认布局是水平布局
* 如果要用垂直布局的话：
* LinearLayoutManager layoutManager = new LinearLayoutManager(this);
* layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
* recyclerView.setLayoutManager(layoutManager);
*/
recyclerView.setLayoutManager(new LinearLayoutManager(this));
//设置item的添加和删除的动画
recyclerView.setItemAnimator(new DefaultItemAnimator());
myHomeAdapter = new HomeAdapter(mList, this);
//设置显示分割线
recyclerView.addItemDecoration(new DividerItemDecoration(RecycleTestActivity.this,DividerItemDecoration.VERTICAL_LIST));
recyclerView.setAdapter(myHomeAdapter);
}
public void setListener(){
myHomeAdapter.setOnItemClickListener(new HomeAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
Toast.makeText(RecycleTestActivity.this,
"点击第" + (position + 1) + "条",Toast.LENGTH_SHORT).show();
}
@Override
public void onItemLongClick(View view, final int position) {
new AlertDialog.Builder(RecycleTestActivity.this)
.setTitle("确定删除吗？")
.setNegativeButton("取消",null)
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
myHomeAdapter.removeData(position);
}
})
.show();
}
});
}
}
DividerItemDecoration (divider line):
/**
* 显示分割线
*/
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
private Drawable mDivider;
private int mOrientation;
public DividerItemDecoration(Context context,int orientation){
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
setOrientation(orientation);
}
public DividerItemDecoration(Context context){
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
}
private void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST){
try {
throw new IllegalAccessException("invalid orientation");
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
mOrientation = orientation;
}
@Override
public void onDraw(@NonNull @NotNull Canvas c, @NonNull @NotNull RecyclerView parent, @NonNull @NotNull RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST){
drawVertical(c,parent);
}else {
drawHorizontal(c,parent);
}
}
private void drawVertical(Canvas c, RecyclerView parent) {
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
RecyclerView v = new RecyclerView(parent.getContext());
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left,top,right,bottom);
mDivider.draw(c);
}
}
private void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicHeight();
mDivider.setBounds(left,top,right,bottom);
mDivider.draw(c);
}
}
@Override
public void getItemOffsets(@NonNull @NotNull Rect outRect, @NonNull @NotNull View view, @NonNull @NotNull RecyclerView parent, @NonNull @NotNull RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST){
outRect.set(0,0,0,mDivider.getIntrinsicHeight());
}else {
outRect.set(0,0,mDivider.getIntrinsicWidth(),0);
}
}
}HomeAdapter (adapter):
/**
* 适配器
*/
public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {
private List<String> mList;
private Context mContext;
private OnItemClickListener mOnItemClickListener;
List<Integer> mHeight;
public HomeAdapter(List<String> mList, Context mContext) {
this.mList = mList;
this.mContext = mContext;
mHeight = new ArrayList<Integer>();
for (int i = 0; i < mList.size(); i++) {
mHeight.add((int)(100 + Math.random() * 300));
}
}
public void removeData(int position){
mList.remove(position);
notifyItemRemoved(position);
}
@NonNull
@NotNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull @NotNull ViewGroup parent, int viewType) {
MyViewHolder holder =
new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.item_recycler,parent,false));
return holder;
}
@Override
public void onBindViewHolder(@NonNull @NotNull HomeAdapter.MyViewHolder holder, int position) {
holder.tv.setText(mList.get(position));
if (mOnItemClickListener != null){
holder.tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int pos = holder.getLayoutPosition();
mOnItemClickListener.onItemClick(holder.tv,pos);
}
});
holder.tv.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
int pos = holder.getLayoutPosition();
mOnItemClickListener.onItemLongClick(holder.tv,pos);
return false;
}
});
}
ViewGroup.LayoutParams lp = holder.tv.getLayoutParams();
lp.height = mHeight.get(position);
holder.tv.setLayoutParams(lp);
}
@Override
public int getItemCount() {
return mList.size();
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView tv;
public MyViewHolder(@NonNull @org.jetbrains.annotations.NotNull View itemView) {
super(itemView);
tv = (TextView)itemView.findViewById(R.id.tv_item);
}
}
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongClick(View view,int position);
}
public void setOnItemClickListener(OnItemClickListener myOnItemClickListener){
this.mOnItemClickListener = myOnItemClickListener;
}
}
activity_recycler_test.xml file:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/id_recyclerview"
android:divider="#ffb900"
android:dividerHeight="1sp"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>item_recycler.xml file:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white">
<TextView
android:id="@+id/tv_item"
android:layout_width="match_parent"
android:layout_height="50dp"
android:gravity="center"
android:text="moon"
android:background="#A3A3A3"/>
</FrameLayout>Second, the implementation of Grid
The effect is as follows:
Add the following code to the useRecyclerView method of the RecyclerViewTest code:
/*
实现GridView功能
*/
recyclerView.setLayoutManager(new StaggeredGridLayoutManager(4,
StaggeredGridLayoutManager.VERTICAL));
recyclerView.addItemDecoration(new DividerItemDecoration(this));3. Realization of Waterfall
The effect is as follows:
1. Define the split distance in item_recycler as 2dp
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="2dp"
android:background="@color/white">
<TextView
android:id="@+id/tv_item"
android:layout_width="match_parent"
android:layout_height="50dp"
android:gravity="center"
android:text="moon"
android:background="#A3A3A3"/>
</FrameLayout>2. Modify the adapter HomeAdapter code:
public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {
private List<String> mList;
private Context mContext;
private OnItemClickListener mOnItemClickListener;
List<Integer> mHeight; //设置随机高度
public HomeAdapter(List<String> mList, Context mContext) {
this.mList = mList;
this.mContext = mContext;
mHeight = new ArrayList<Integer>();
for (int i = 0; i < mList.size(); i++) {
mHeight.add((int)(100 + Math.random() * 300));
}
}
public void removeData(int position){
mList.remove(position);
notifyItemRemoved(position);
}
@NonNull
@NotNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull @NotNull ViewGroup parent, int viewType) {
MyViewHolder holder =
new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.item_recycler,parent,false));
return holder;
}
@Override
public void onBindViewHolder(@NonNull @NotNull HomeAdapter.MyViewHolder holder, int position) {
holder.tv.setText(mList.get(position));
if (mOnItemClickListener != null){
holder.tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int pos = holder.getLayoutPosition();
mOnItemClickListener.onItemClick(holder.tv,pos);
}
});
holder.tv.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
int pos = holder.getLayoutPosition();
mOnItemClickListener.onItemLongClick(holder.tv,pos);
return false;
}
});
}
//瀑布流实现
ViewGroup.LayoutParams lp = holder.tv.getLayoutParams();
lp.height = mHeight.get(position);
holder.tv.setLayoutParams(lp);
}
@Override
public int getItemCount() {
return mList.size();
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView tv;
public MyViewHolder(@NonNull @org.jetbrains.annotations.NotNull View itemView) {
super(itemView);
tv = (TextView)itemView.findViewById(R.id.tv_item);
}
}
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongClick(View view,int position);
}
public void setOnItemClickListener(OnItemClickListener myOnItemClickListener){
this.mOnItemClickListener = myOnItemClickListener;
}
}