我有三种不同的布局cardListLayout,titleLayout,cardMagazineLayout,将来可能会有更多,用作onCreateViewHolder方法的视图. 我想在onCreateViewHolder方法中切换视图,以便用户从AlertDialog列表中选择 这个在M
我想在onCreateViewHolder方法中切换视图,以便用户从AlertDialog列表中选择
这个在MainActivity中的onOptionsItemSelected其中有菜单项“更改布局”,以便当用户按下它时出现AlertDialog列表
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.change_layout) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle(getString(R.string.choose_layout));
String[] layouts = {"Title Layout", "Cards List", "Card Magazine Layout"};
builder.setItems(layouts, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int index) {
switch (index) {
case 0: // Title layout
Toast.makeText(MainActivity.this,
"Title layout", Toast.LENGTH_LONG).show();
break;
case 1: // Cards List
Toast.makeText(MainActivity.this,
"Card list", Toast.LENGTH_LONG).show();
break;
case 2: // Cards Magazine Layout
Toast.makeText(MainActivity.this,
"Card Magazine Layout", Toast.LENGTH_LONG).show();
}
}
});
这是我的自定义适配器类PostAdapter
public class PostAdapter extends RecyclerView.Adapter<PostAdapter.PostViewHolder> {
private Context context;
private List<Item> items;
public PostAdapter(Context context, List<Item> items) {
this.context = context;
this.items = items;
}
@NonNull
@Override
public PostAdapter.PostViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
// here's the three layouts that I can't switch between it
View cardsListLayout = inflater.inflate(R.layout.post_item_card_layout, parent, false);
View titleLayout = inflater.inflate(R.layout.post_item_grid_layout, parent, false);
View cardMagazineLayout = inflater.inflate(R.layout.card_magazine_layout,parent,false);
return new PostViewHolder(titleLayout);
}
@Override
public void onBindViewHolder(@NonNull PostViewHolder holder, int position) {
final Item item = items.get(position);
holder.postTitle.setText(item.getTitle());
final Document document = Jsoup.parse(item.getContent());
Elements elements = document.select("img");
Log.e("CODE", "Image: " + elements.get(0).attr("src"));
// Log.d("Text",document.text());
// holder.postDescription.setText(document.text());
Glide.with(context).load(elements.get(0).attr("src"))
.into(holder.postImage);
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context, DetailsActivity.class);
intent.putExtra("url", item.getUrl());
intent.putExtra("title", item.getTitle());
intent.putExtra("content", item.getContent());
int youtubeThumbnailImagesetVisibility = 0;
Element element = document.body();
String youtubeThumbnailImageSrc = "";
String youTubeLink = "";
for (Element e : element.getElementsByClass
("YOUTUBE-iframe-video")) {
youtubeThumbnailImageSrc = e.attr("data-thumbnail-src");
youTubeLink = e.attr("src");
Log.e("YouTube thumbnail", youtubeThumbnailImageSrc);
Log.e("Youtube link", youTubeLink);
}
if (youtubeThumbnailImageSrc.isEmpty()) {
youtubeThumbnailImagesetVisibility = 8;
intent.putExtra("youtubeThumbnailImagesetVisibility",
youtubeThumbnailImagesetVisibility);
} else {
intent.putExtra("youtubeThumbnailImageSrc", youtubeThumbnailImageSrc);
intent.putExtra("youTubeLink", youTubeLink);
}
// String imageSrc = elements.get(0).attr("src");
// intent.putExtra("blogImage",imageSrc);
context.startActivity(intent);
}
});
}
@Override
public int getItemCount() {
return items.size();
}
public class PostViewHolder extends RecyclerView.ViewHolder {
ImageView postImage;
TextView postTitle;
TextView postDescription;
public PostViewHolder(View itemView) {
super(itemView);
postImage = itemView.findViewById(R.id.postImage);
postTitle = itemView.findViewById(R.id.postTitle);
postDescription = itemView.findViewById(R.id.postDescription);
}
}
}
我为每一个创建了两个不同的布局管理器,有一个LinearLayoutManager和GridLayoutManager,目前我使用了GridLayout,所以我暂时评论了LinearLayoutManger,直到我知道如何在它们之间切换
// linearLayoutManager = new LinearLayoutManager(this);
gridLayoutManager = new GridLayoutManager(this, 2, RecyclerView.VERTICAL, false);
// recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setLayoutManager(gridLayoutManager);
我渴望的结果
无需为此使用多个Recyclerview您可以使用具有多个viewType的单个Recyclerview实现此目的
当您想要更改Recyclerview的布局时,只需更改Recyclerview的LayoutManager和viewType即可
示例代码
试试这种方式
首先为多个viewType创建三个布局
grid_layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="150dp"
android:layout_height="150dp"
app:cardElevation="10dp"
app:cardUseCompatPadding="true">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:layout_width="match_parent"
android:layout_height="150dp"
android:adjustViewBounds="true"
android:contentDescription="@string/app_name"
android:scaleType="centerCrop"
android:src="@drawable/dishu" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="#6a000000"
android:gravity="center"
android:padding="10dp"
android:text="dummy text"
android:textColor="@android:color/white" />
</RelativeLayout>
</android.support.v7.widget.CardView>
cardlist_layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 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"
app:cardElevation="10dp"
app:cardUseCompatPadding="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:orientation="vertical">
<ImageView
android:layout_width="match_parent"
android:layout_height="150dp"
android:adjustViewBounds="true"
android:contentDescription="@string/app_name"
android:scaleType="centerCrop"
android:src="@drawable/dishu" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart="5dp"
android:paddingEnd="10dp"
android:text="Dummy Title"
android:textColor="@android:color/black"
android:textStyle="bold" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart="5dp"
android:paddingEnd="10dp"
android:text="Dummy Tex" />
</LinearLayout>
</android.support.v7.widget.CardView>
title_layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 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"
app:cardElevation="10dp"
app:cardUseCompatPadding="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center">
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart="5dp"
android:paddingEnd="5dp"
android:text="dummy text"
android:textColor="@android:color/black"
android:textStyle="bold" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="start"
android:paddingStart="5dp"
android:paddingEnd="5dp"
android:text="I have three different layouts cardsListLayout , titleLayout , cardMagazineLayoutand there may be more in the future, which used as a views on onCreateViewHolder method." />
</LinearLayout>
<ImageView
android:layout_width="wrap_content"
android:layout_height="150dp"
android:adjustViewBounds="true"
android:contentDescription="@string/app_name"
android:scaleType="centerCrop"
android:src="@drawable/dishu" />
</LinearLayout>
</android.support.v7.widget.CardView>
DataAdapter
package neel.com.recyclerviewdemo;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class DataAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
public static final int ITEM_TYPE_GRID = 0;
public static final int ITEM_TYPE_CARD_LIST = 1;
public static final int ITEM_TYPE_TITLE_LIST = 2;
private Context mContext;
private int VIEW_TYPE = 0;
public DataAdapter(Context mContext) {
this.mContext = mContext;
}
public void setVIEW_TYPE(int viewType) {
VIEW_TYPE = viewType;
notifyDataSetChanged();
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = null;
// check here the viewType and return RecyclerView.ViewHolder based on view type
switch (VIEW_TYPE) {
case ITEM_TYPE_GRID:
// if VIEW_TYPE is Grid than return GridViewHolder
view = LayoutInflater.from(mContext).inflate(R.layout.grid_layout, parent, false);
return new GridViewHolder(view);
case ITEM_TYPE_CARD_LIST:
// if VIEW_TYPE is Card List than return CardListViewHolder
view = LayoutInflater.from(mContext).inflate(R.layout.cardlist_layout, parent, false);
return new CardListViewHolder(view);
case ITEM_TYPE_TITLE_LIST:
// if VIEW_TYPE is Title List than return TitleListViewHolder
view = LayoutInflater.from(mContext).inflate(R.layout.title_layout, parent, false);
return new TitleListViewHolder(view);
}
return new GridViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
final int itemType = getItemViewType(position);
// First check here the View Type
// than set data based on View Type to your recyclerview item
if (itemType == ITEM_TYPE_GRID) {
if (holder instanceof CardViewHolder) {
GridViewHolder viewHolder = (GridViewHolder) holder;
// write here code for your grid list
}
} else if (itemType == ITEM_TYPE_CARD_LIST) {
if (holder instanceof CardViewHolder) {
CardListViewHolder buttonViewHolder = (CardListViewHolder) holder;
// write here code for your grid list
}
} else if (itemType == ITEM_TYPE_TITLE_LIST) {
if (holder instanceof CardViewHolder) {
TitleListViewHolder buttonViewHolder = (TitleListViewHolder) holder;
// write here code for your TitleListViewHolder
}
}
}
@Override
public int getItemCount() {
return 40;
}
// RecyclerView.ViewHolder class for gridLayoutManager
public class GridViewHolder extends RecyclerView.ViewHolder {
public GridViewHolder(@NonNull View itemView) {
super(itemView);
}
}
// RecyclerView.ViewHolder class for Card list View
public class CardListViewHolder extends RecyclerView.ViewHolder {
public CardListViewHolder(@NonNull View itemView) {
super(itemView);
}
}
// RecyclerView.ViewHolder class for Title list View
public class TitleListViewHolder extends RecyclerView.ViewHolder {
public TitleListViewHolder(@NonNull View itemView) {
super(itemView);
}
}
}
MainActivity
package neel.com.recyclerviewdemo;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity {
DataAdapter dataAdapter;
private RecyclerView myRecyclerView;
private LinearLayoutManager linearLayoutManager;
private GridLayoutManager gridLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myRecyclerView = findViewById(R.id.myRecyclerView);
myRecyclerView.setHasFixedSize(true);
linearLayoutManager = new LinearLayoutManager(this);
gridLayoutManager = new GridLayoutManager(this, 3);
myRecyclerView.setLayoutManager(gridLayoutManager);
dataAdapter = new DataAdapter(this);
myRecyclerView.setAdapter(dataAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.home_menu, menu);
// return true so that the menu pop up is opened
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.action_dialog) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Please choose a layout");
String[] layouts = {"Title Layout", "Cards List", "Grid View"};
builder.setItems(layouts, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int index) {
switch (index) {
case 0: // Title layout
dataAdapter.setVIEW_TYPE(2);
myRecyclerView.setLayoutManager(linearLayoutManager);
myRecyclerView.setAdapter(dataAdapter);
break;
case 1: // Cards List
dataAdapter.setVIEW_TYPE(1);
myRecyclerView.setLayoutManager(linearLayoutManager);
myRecyclerView.setAdapter(dataAdapter);
break;
case 2: // Grid Layout
dataAdapter.setVIEW_TYPE(0);
myRecyclerView.setLayoutManager(gridLayoutManager);
myRecyclerView.setAdapter(dataAdapter);
}
}
});
builder.show();
}
return super.onOptionsItemSelected(item);
}
}
activity_main layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/myRecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
OUTPUT
https://youtu.be/L3slKTy2bzI