安卓高级3 RecyclerView 和cardView使用案例
cardView:
添加依赖:在Studio搜索cardview即可 在V7包中
或者直接在gradle中添加
compile 'com.android.support:cardview-v7:24.0.0'
cardView 完成一些绚丽特效使用:
属性:
app:cardElevation=”10dp”添加景深 (阴影效果让其更立体)
app:cardCornerRadius=”10dp”四边圆角值
app:cardBackgroundColor=”@android:color/holo_blue_ligh”背景色
android:foreground=”?android:attr/selectableItemBackground” 用户点击时会生成涟漪效果
<?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"
android:layout_margin="10dp"
android:foreground="?android:attr/selectableItemBackground"
android:orientation="vertical"
app:cardBackgroundColor="@android:color/holo_blue_light"
app:cardCornerRadius="10dp"
app:cardElevation="10dp">
<TextView
android:id="@+id/item_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="30dp"
android:layout_marginTop="30dp"
android:textColor="@android:color/white"
android:textSize="20sp" />
</android.support.v7.widget.CardView>
效果图:
RecyclerView :
同样需要添加依赖 和上诉一样.
compile ‘com.android.support:recyclerview-v7:24.0.0’
可以实现GridView ListView 和流布局并且可以指定方向,和数据颠倒等
使用方法和适配器介绍:
在布局文件写入RecyclerView
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout 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" tools:context="qianfeng.com.day38_recyclerview.MainActivity"> <android.support.v7.widget.RecyclerView android:id="@+id/recyclerView" android:layout_width="match_parent" android:layout_height="match_parent"></android.support.v7.widget.RecyclerView> </RelativeLayout>
写布局管理器(多种) 和适配器:
这里大家可以先不用管适配后面详解
package qianfeng.com.day38_recyclerview; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.widget.Toast; import java.util.ArrayList; import java.util.List; /**java * RecyclerView: * 升级版的ListView 融合了 ListView GridView 瀑布流 横纵向滑动 * RecyclerView 使用 LayoutManager 进行布局管理 * 1.LinearLayoutManager 线性布局管理器 -- > 横向或纵向的ListView展示效果 * 2.GridLayoutManager 网格布局管理器 ---> 横向或纵向的 GridView 展示效果 * 3.StraggXXXXXXXXXX 瀑布流 * * LayoutManager * 实例化的时候 参数 上下文对象,横竖展示标记, 反转 * * recyclerView 通过setLayoutManager() 方式 设置 布局管理器 * * RecyclerAdapter * 是抽象类 * 需要继承与 RecyclerView.Adapter<VH></> * * 传入的 ViewHodler 对象 必须继承与 RecyclerView.ViewHolder * 并重写 含有ItemView 的 构造方法 * * 继承 RecyclerView.Adapter<VH></>类之后 需要重写三个方法 * 1.getItemCount * 返回数据源的长度 * 2.onCreateViewHolder * 实例化 itmeView * 并创建ViewHolder 对象 将其返回 * 3.onBindViewHolder * 数据源 与ViewHolder 的持有View 进行绑定 * * 设置监听器 * RecyclerView 本身并不含有监听器 需要自己添加 * * 在适配器中定义接口及方法 * 给ItemView设置监听 并 对外暴露出接口 * 由RecyclerView 进行监听 点击事件 * * 获取ItemView 的position * RecyclerView .getChildAdapterPosition(ItemView) * * * RecyclerView 没有分割线属性 * 不推荐使用 * LinearLayoutmanager 纵向模式下 * 可以使用 DividerItemDecoration 进行 分割线修改 * * recyclerView.addItemDecoration(); 添加分割线属性 * * value -- style * 添加一个 android:listDivider 属性 * 值 添加 shape 或者 图片 作为分割线展示 * 如果只添加颜色 则 没有高度 无法展示 * * 推荐使用的:(不需要分割线) * * CardView * * */ public class MainActivity extends AppCompatActivity implements MyRecyclerAdapter.OnItemClickListener { private RecyclerView recyclerView; private List<String> list = new ArrayList<>(); private MyRecyclerAdapter myRecyclerAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 实例化RecyclerView 对象 recyclerView = (RecyclerView) findViewById(R.id.recyclerView); /** * 上下文对象 * 方向 * 是否反转 * 如果翻转 数据颠倒并且进入界面时跳到最后显示第一个item(相当于正向的第一个数据item) * 如果方向是横向LinearLayoutManager.HORIZONTAL 那么整个activity只显示一个item,向右滑动即可显示下一个item和Viewpager相识 */ LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false); // GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 4, LinearLayoutManager.HORIZONTAL, false); recyclerView.setLayoutManager(linearLayoutManager); // 添加自定义的 分割线 (不推荐) recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST)); initData(); // 设置适配器 myRecyclerAdapter = new MyRecyclerAdapter(list, this, recyclerView, this); recyclerView.setAdapter(myRecyclerAdapter); } private void initData() { for (int i = 0; i < 50; i++) { list.add("哈哈哈哈" + i); } } //以下监听为我们在适配器中添加的 @Override public void onItemClickListener(int position) { Toast.makeText(MainActivity.this, "点击————" + position, Toast.LENGTH_LONG).show(); } @Override public void onItemLongClickListener(int position) { Toast.makeText(MainActivity.this, "长按————" + position, Toast.LENGTH_LONG).show(); } }
效果图:
如果上诉案例写成竖直方向:
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
效果图
- 反向:大家可以自己试试:这里直接说结果,上诉竖直方向会直接滑到哈哈0 (此时哈哈0是在列表底部的注意)
上诉案例:用改用gridlayout
//没行4个 GridLayoutManager(this, 4, LinearLayoutManager.HORIZONTAL, false); recyclerView.setLayoutManager(gridLayoutManager);
效果图:
另一个方向参考上一个Linear案例适配器
package qianfeng.com.day38_recyclerview;
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 ${Mr.Zhao} on 2016/10/19.
*/
public class MyRecyclerAdapter extends RecyclerView.Adapter<MyRecyclerAdapter.MyViewHolder> {
List<String> list;
Context context;
LayoutInflater inflater;
RecyclerView recyclerView;
private OnItemClickListener listener;
public interface OnItemClickListener {
public void onItemClickListener(int position);
public void onItemLongClickListener(int position);
}
public MyRecyclerAdapter(List<String> list, Context context, RecyclerView recyclerView, OnItemClickListener listener) {
this.list = list;
this.context = context;
this.recyclerView = recyclerView;
inflater = LayoutInflater.from(context);
this.listener = listener;
}
// 该方法为 创建ViewHolder 使用
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// 实例化 itemView
View view = inflater.inflate(R.layout.item_layout, parent, false);
return new MyViewHolder(view);
}
// 该方法为 绑定数据使用
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.item_tv.setText(list.get(position));
}
// 返回数据长度
@Override
public int getItemCount() {
return list.size();
}
// 定义 ViewHolder
public class MyViewHolder extends RecyclerView.ViewHolder {
TextView item_tv;
// 必须实现的有参构造
public MyViewHolder(final View itemView) {
super(itemView);
// 实例化 textView
item_tv = ((TextView) itemView.findViewById(R.id.item_tv));
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 获取itemView 的 位置
int childPosition = recyclerView.getChildAdapterPosition(itemView);
// 监听方法
listener.onItemClickListener(childPosition);
}
});
itemView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
int childAdapterPosition = recyclerView.getChildAdapterPosition(itemView);
listener.onItemLongClickListener(childAdapterPosition);
return true;
}
});
}
}
}
- 一个分割线类
package qianfeng.com.day38_recyclerview;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
/**
* ListView 模式 下的 下划线
* Created by ${Mr.Zhao} on 2016/5/26.
*
* 可以自由更改分割线 android.R.attr.listDivider
* 去 values 的 styles 下 添加 android:listDivider 属性 在面的值 可以任意修改
* 图片或者颜色 或者 Drawable 资源
*/
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 void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
@Override
public void onDraw(Canvas c, RecyclerView parent) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else {
drawHorizontal(c, parent);
}
}
public 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);
}
}
public 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(Rect outRect, int itemPosition, RecyclerView parent) {
if (mOrientation == VERTICAL_LIST) {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
}
}
}
多布局
适配器中有多个viewhold然后根据 返回类型确定用哪个viewhold
package com.example.administrator.myapplication;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private GridLayoutManager linearLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.RecyclerView);
linearLayoutManager = new GridLayoutManager(this,3,GridLayoutManager.VERTICAL,false);
recyclerView.setLayoutManager(linearLayoutManager);
Myadapter myadapter = new Myadapter();
recyclerView.setAdapter(myadapter);
//找到第一个显示的位置
linearLayoutManager.findFirstVisibleItemPosition();
//找到最后一个显示的位置
linearLayoutManager.findLastVisibleItemPosition();
new Thread(){
@Override
public void run() {
while (true){
try {
sleep(300);
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.e("tag", linearLayoutManager.findFirstVisibleItemPosition()+"");
}
}
}.start();
}
class Myadapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
class MyViewHold extends RecyclerView.ViewHolder{
public MyViewHold(View itemView) {
super(itemView);
}
}
class MyViewHold2 extends RecyclerView.ViewHolder{
public MyViewHold2(View itemView) {
super(itemView);
}
}
//自定义一个返回类型实现多布局
@Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View inflate = getLayoutInflater().inflate(R.layout.item, parent, false);
MyViewHold2 myViewHold2= new MyViewHold2(inflate) ;
//这里可以自定义适配器viewhold实现多布局
/* switch (viewType){
default:
}*/
return myViewHold2;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof MyViewHold2){
}else if (holder instanceof MyViewHold){
}
}
@Override
public int getItemCount() {
return 500;
}
}
}