RecycleView新增頭部和底部
阿新 • • 發佈：2019-02-03
實現思路
- 在Adapter中定義不同的佈局和item狀態
- 判斷item的狀態，載入對應的佈局檔案
例項程式碼
在gradle中新增下面的依賴
compile 'com.android.support:recyclerview-v7:23.1.0'
compile 'com.android.support:cardview-v7:23.1.0'佈局檔案
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" rv_header.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width rv_footer.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/cv_footer"
android:foreground="?android:attr/selectableItemBackground"
app:cardCornerRadius="6dp"
app:cardElevation="4dp"
app:cardBackgroundColor="#E91E63"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="100dp"
android:gravity="center">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="footer"
android:id="@+id/tv_footer"
android:textSize="30sp"
android:textColor="#ffffff"
android:padding="4dp"
android:layout_margin="8dp"/>
</LinearLayout>
</android.support.v7.widget.CardView>rv_item.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/cv_item"
android:foreground="?android:attr/selectableItemBackground"
app:cardCornerRadius="6dp"
app:cardElevation="4dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="item"
android:id="@+id/tv_content"
android:textSize="22sp"
android:padding="4dp"
android:layout_margin="8dp"/>
</LinearLayout>
</android.support.v7.widget.CardView>java實現
MainActivity.java
package com.gjg.learn.recycleview_head_foot;
import android.os.Bundle;
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.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private HeaderBottomAdapter adapter;
private LinearLayoutManager layoutManager;
StaggeredGridLayoutManager staggeredGridLayoutManager;
//模擬資料
public String [] texts={"java","python","C++","Php",".NET",
"js","Ruby","Swift","OC","C","html","css",
"C#","嵌入式"
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.rv_list);
adapter=new HeaderBottomAdapter(this,texts);
//線性佈局
layoutManager=new LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setAdapter(adapter);
initEvent();
}
private void initEvent() {
adapter.setOnItemClickListener(new HeaderBottomAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
Toast.makeText(MainActivity.this, "你點選了"+((position==0)?"header":((position==texts.length+1)?"footer":texts[position-1])),
Toast.LENGTH_SHORT).show();
}
@Override
public void onItemLongClick(View view, int position) {
Toast.makeText(MainActivity.this, "你長按了"+((position==0)?"header":((position==texts.length+1)?"footer":texts[position-1])),
Toast.LENGTH_SHORT).show();
}
});
}
}
HeaderBottomAdapter.java
package com.gjg.learn.recycleview_head_foot;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
/**
* Created by Junguang_Gao on 2016/11/24.
*/
public class HeaderBottomAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
//item型別
public static final int ITEM_TYPE_HEADER = 0;
public static final int ITEM_TYPE_CONTENT = 1;
public static final int ITEM_TYPE_BOTTOM = 2;
//item的高度
private List<Integer> mHeights;
private LayoutInflater mLayoutInflater;
private Context mContext;
private String[] datas;
private int mHeaderCount=1;//頭部View個數
private int mBottomCount=1;//底部View個數
public HeaderBottomAdapter(Context context,String[] datas) {
mContext = context;
this.datas=datas;
mLayoutInflater = LayoutInflater.from(context);
}
//判斷當前item是否是HeadView
public boolean isHeaderView(int position) {
return mHeaderCount != 0 && position < mHeaderCount;
}
//內容長度
public int getContentItemCount(){
return datas.length;
}
//判斷當前item是否是FooterView
public boolean isBottomView(int position) {
return mBottomCount != 0 && position >= (mHeaderCount + getContentItemCount());
}
//判斷當前item型別
@Override
public int getItemViewType(int position) {
int dataItemCount = getContentItemCount();
if (mHeaderCount != 0 && position < mHeaderCount) {
//頭部View
return ITEM_TYPE_HEADER;
} else if (mBottomCount != 0 && position >= (mHeaderCount + dataItemCount)) {
//底部View
return ITEM_TYPE_BOTTOM;
} else {
//內容View
return ITEM_TYPE_CONTENT;
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType ==ITEM_TYPE_HEADER) {
return new HeaderViewHolder(mLayoutInflater.inflate(R.layout.rv_header, parent, false));
} else if (viewType == ITEM_TYPE_CONTENT) {
return new ContentViewHolder(mLayoutInflater.inflate(R.layout.rv_item, parent, false));
} else if (viewType == ITEM_TYPE_BOTTOM) {
return new BottomViewHolder(mLayoutInflater.inflate(R.layout.rv_footer, parent, false));
}
return null;
}
@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
if (holder instanceof HeaderViewHolder) {
} else if (holder instanceof ContentViewHolder) {
((ContentViewHolder) holder).textView.setText(datas[position - mHeaderCount]);
} else if (holder instanceof BottomViewHolder) {
}
// 如果設定了回撥，則設定點選事件
if (mOnItemClickListener != null)
{
//itemView:ViewHolder的一個item
holder.itemView.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
int pos = holder.getLayoutPosition();
mOnItemClickListener.onItemClick(holder.itemView, pos);
}
});
holder.itemView.setOnLongClickListener(new View.OnLongClickListener()
{
@Override
public boolean onLongClick(View v)
{
int pos = holder.getLayoutPosition();
mOnItemClickListener.onItemLongClick(holder.itemView, pos);
return false;
}
});
}
}
@Override
public int getItemCount() {
return mHeaderCount + getContentItemCount() + mBottomCount;
}
//內容 ViewHolder
public static class ContentViewHolder extends RecyclerView.ViewHolder {
private TextView textView;
public ContentViewHolder(View itemView) {
super(itemView);
textView=(TextView)itemView.findViewById(R.id.tv_content);
}
}
//頭部 ViewHolder
public static class HeaderViewHolder extends RecyclerView.ViewHolder {
public HeaderViewHolder(View itemView) {
super(itemView);
}
}
//底部 ViewHolder
public static class BottomViewHolder extends RecyclerView.ViewHolder {
public BottomViewHolder(View itemView) {
super(itemView);
}
}
public interface OnItemClickListener{
void onItemClick(View view, int position);
void onItemLongClick(View view, int position);
}
private OnItemClickListener mOnItemClickListener;
public void setOnItemClickListener(OnItemClickListener mOnItemClickListener) {
this.mOnItemClickListener = mOnItemClickListener;
}
}
實現效果（LinearLayout）
表格佈局的實現
將上面的線性佈局的程式碼改成下面的程式碼
gridLayoutManager = new GridLayoutManager(MainActivity.this, 2);
mRecyclerView.setLayoutManager(gridLayoutManager);//這裡用線性宮格顯示 類似於grid view
mRecyclerView.setAdapter(adapter );
//設定頭部和底部的item單獨佔據一行
gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return (adapter.isHeaderView(position) || adapter.isBottomView(position)) ? gridLayoutManager.getSpanCount() : 1;
}
});實現效果
瀑布流的實現
將程式碼改為下面的程式碼
staggeredGridLayoutManager=new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
mRecyclerView.setLayoutManager(staggeredGridLayoutManager);
mRecyclerView.setAdapter(adapter);並在構造方法中儲存item的高度
mHeights = new ArrayList<Integer>();
for (int i = 0; i < datas.length; i++)
{
mHeights.add( (int) (100 + Math.random() * 300));
}將onBindViewHolder改為下面：
if (holder instanceof HeaderViewHolder) {
// 獲取cardview的佈局屬性，記住這裡要是佈局的最外層的控制元件的佈局屬性，如果是裡層的會報cast錯誤
StaggeredGridLayoutManager.LayoutParams slp = (StaggeredGridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
// 最最關鍵一步，設定當前view佔滿列數，這樣就可以佔據兩列實現頭部了
slp.setFullSpan(true);
} else if (holder instanceof ContentViewHolder) {
ViewGroup.LayoutParams lp = ((ContentViewHolder) holder).textView.getLayoutParams();
lp.height = mHeights.get(position-1);
((ContentViewHolder) holder).textView.setLayoutParams(lp);
((ContentViewHolder) holder).textView.setText(datas[position - mHeaderCount]);
} else if (holder instanceof BottomViewHolder) {
StaggeredGridLayoutManager.LayoutParams slp = (StaggeredGridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
slp.setFullSpan(true);
}實現效果
