RecyclerView 的用法探秘 (基础篇)
ListView 一统天下的时代,是我目前用的最多一个控件;从事Android开发几年多来,很多时候都是围绕着这个东东码代码;现在,终于迎来了解放双手的时候。RecyclerView 的时代正式来临;
先简单的说一下我在使用这个控件的基本思路和步骤:
1. 首先构建数据模型:即model:——javeBean;
2. 新建布局文件:Item(每个列表项目中都有哪些控件),为适配器做准备;
3. 新建Activity布局,即包含RecyclerView 的布局;
4. 核心工作,适配器的编写;很多时候都是在编写适配器;
话不多说,直接上代码:数据模型的代码此处略过,从布局文件开始
item_envent.xml
<?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="44dp"
android:minHeight="44dp"
android:background="@drawable/bar_case_bg"
>
<ImageView
android:id="@+id/iv_not_onclick"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="18dp"
/>
<TextView
android:id="@+id/event_title_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@color/bg_black"
android:textSize="@dimen/content_fonts_size_16"
android:text="打开开关"
android:paddingLeft="13.0dip"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
</RelativeLayout>
Activity 布局中包含RecyelerView
activity_condition.xml
<?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"
android:background="@color/bg_content"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/device_condition_rcy"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/tips_tx"
style="@style/content_text"
android:layout_centerInParent="true"
android:visibility="gone"/>
</RelativeLayout>
下面就是通用适配器:一次编写,处处运行;这个通用适配器用泛型的方式进行具体业务数据的绑定;它继承了RecyclerView.Adapter;
package com.cloudring.smarthome.adapter;
import android.content.Context;
import android.support.annotation.Nullable;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.List;
/**
* Created by qingwufeiyang
* <p>
* Description:自定义通用的RecyclerView Adapter
*/
public abstract class CommonAdapter<T> extends RecyclerView.Adapter<CommonViewHolder> {
protected Context mContext;
protected List<T> mDatas = new ArrayList<>();
protected OnItemClickListener<T> mOnItemClickListener;
private int mItemViewID;
public CommonAdapter(Context context, List<T> datas, int itemView) {
this.mContext = context;
this.mDatas = datas;
this.mItemViewID = itemView;
}
public void setList(List<T> mDatas) {
this.mDatas = mDatas;
this.notifyDataSetChanged();
}
@Override
public CommonViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
CommonViewHolder holder = CommonViewHolder.createViewHolder(mContext, parent, mItemViewID);
setListener(parent, holder, viewType);
return holder;
}
public abstract void convert(CommonViewHolder holder, T t);
protected boolean isEnabled(int viewType) {
return true;
}
protected void setListener(final ViewGroup parent, final CommonViewHolder viewHolder, int viewType) {
if (!isEnabled(viewType)) return;
viewHolder.getConvertView().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mOnItemClickListener != null) {
int position = viewHolder.getLayoutPosition();
T t = null;
if (position >= 0 && position < mDatas.size()) {
t = mDatas.get(position);
}
mOnItemClickListener.onItemClick(v, viewHolder, t, position);
}
}
});
viewHolder.getConvertView().setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
if (mOnItemClickListener != null) {
int position = viewHolder.getLayoutPosition();
T t = null;
if (position >= 0 && position < mDatas.size()) {
t = mDatas.get(position);
}
return mOnItemClickListener.onItemLongClick(v, viewHolder, t, position);
}
return false;
}
});
}
@Override
public void onBindViewHolder(CommonViewHolder holder, int position) {
convert(holder, mDatas.get(position));
}
@Override
public int getItemCount() {
int itemCount = mDatas.size();
return itemCount;
}
public List<T> getDatas() {
return mDatas;
}
public interface OnItemClickListener<T> {
void onItemClick(View view, RecyclerView.ViewHolder holder, @Nullable T o, int position);
boolean onItemLongClick(View view, RecyclerView.ViewHolder holder, @Nullable T o, int position);
}
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.mOnItemClickListener = onItemClickListener;
}
}
接下来看看CommonViewHolder 的实现逻辑:
package com.cloudring.smarthome.adapter;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.v7.widget.RecyclerView;
import android.text.util.Linkify;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.widget.CheckBox;
import android.widget.Checkable;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TextView;
/**
* Created by qingwufeiyang on Mon
*
* 自定义通用的RecyclerView ViewHolder
*/
public class CommonViewHolder extends RecyclerView.ViewHolder {
private SparseArray<View> mViews;
private View mConvertView;
private Context mContext;
public CommonViewHolder(Context context, View itemView) {
super(itemView);
mContext = context;
mConvertView = itemView;
mViews = new SparseArray<View>();
}
public static CommonViewHolder createViewHolder(Context context, View itemView) {
CommonViewHolder holder = new CommonViewHolder(context, itemView);
return holder;
}
public static CommonViewHolder createViewHolder(Context context,
ViewGroup parent, int layoutId) {
View itemView = LayoutInflater.from(context).inflate(layoutId, parent,
false);
CommonViewHolder holder = new CommonViewHolder(context, itemView);
return holder;
}
/**
* 通过viewId获取控件
*
* @param viewId
* @return
*/
public <T extends View> T getView(int viewId) {
View view = mViews.get(viewId);
if (view == null) {
view = mConvertView.findViewById(viewId);
mViews.put(viewId, view);
}
return (T) view;
}
public View getConvertView() {
return mConvertView;
}
/****以下为辅助方法*****/
/**
* 设置TextView的值
*
* @param viewId
* @param text
* @return
*/
public CommonViewHolder setText(int viewId, String text) {
TextView tv = getView(viewId);
tv.setText(text);
return this;
}
public CommonViewHolder setImageResource(int viewId, int resId) {
ImageView view = getView(viewId);
view.setImageResource(resId);
return this;
}
public CommonViewHolder setImageBitmap(int viewId, Bitmap bitmap) {
ImageView view = getView(viewId);
view.setImageBitmap(bitmap);
return this;
}
public CommonViewHolder setImageDrawable(int viewId, Drawable drawable) {
ImageView view = getView(viewId);
view.setImageDrawable(drawable);
return this;
}
public CommonViewHolder setBackgroundColor(int viewId, int color) {
View view = getView(viewId);
view.setBackgroundColor(color);
return this;
}
public CommonViewHolder setBackgroundRes(int viewId, int backgroundRes) {
View view = getView(viewId);
view.setBackgroundResource(backgroundRes);
return this;
}
public CommonViewHolder setTextColor(int viewId, int textColor) {
TextView view = getView(viewId);
view.setTextColor(textColor);
return this;
}
public CommonViewHolder setTextColorRes(int viewId, int textColorRes) {
TextView view = getView(viewId);
view.setTextColor(mContext.getResources().getColor(textColorRes));
return this;
}
@SuppressLint("NewApi")
public CommonViewHolder setAlpha(int viewId, float value) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getView(viewId).setAlpha(value);
} else {
// Pre-honeycomb hack to set Alpha value
AlphaAnimation alpha = new AlphaAnimation(value, value);
alpha.setDuration(0);
alpha.setFillAfter(true);
getView(viewId).startAnimation(alpha);
}
return this;
}
public CommonViewHolder setVisible(int viewId, boolean visible) {
View view = getView(viewId);
view.setVisibility(visible ? View.VISIBLE : View.GONE);
return this;
}
public CommonViewHolder linkify(int viewId) {
TextView view = getView(viewId);
Linkify.addLinks(view, Linkify.ALL);
return this;
}
public CommonViewHolder setTypeface(Typeface typeface, int... viewIds) {
for (int viewId : viewIds) {
TextView view = getView(viewId);
view.setTypeface(typeface);
view.setPaintFlags(view.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
}
return this;
}
public CommonViewHolder setProgress(int viewId, int progress) {
ProgressBar view = getView(viewId);
view.setProgress(progress);
return this;
}
public CommonViewHolder setProgress(int viewId, int progress, int max) {
ProgressBar view = getView(viewId);
view.setMax(max);
view.setProgress(progress);
return this;
}
public CommonViewHolder setMax(int viewId, int max) {
ProgressBar view = getView(viewId);
view.setMax(max);
return this;
}
public CommonViewHolder setRating(int viewId, float rating) {
RatingBar view = getView(viewId);
view.setRating(rating);
return this;
}
public CommonViewHolder setRating(int viewId, float rating, int max) {
RatingBar view = getView(viewId);
view.setMax(max);
view.setRating(rating);
return this;
}
public CommonViewHolder setTag(int viewId, Object tag) {
View view = getView(viewId);
view.setTag(tag);
return this;
}
public CommonViewHolder setTag(int viewId, int key, Object tag) {
View view = getView(viewId);
view.setTag(key, tag);
return this;
}
public CommonViewHolder setChecked(int viewId, boolean checked) {
Checkable view = (Checkable) getView(viewId);
view.setChecked(checked);
return this;
}
/**
* 关于事件的
*/
public CommonViewHolder setOnClickListener(int viewId,
View.OnClickListener listener) {
View view = getView(viewId);
view.setOnClickListener(listener);
return this;
}
public CommonViewHolder setOnTouchListener(int viewId,
View.OnTouchListener listener) {
View view = getView(viewId);
view.setOnTouchListener(listener);
return this;
}
public CommonViewHolder setOnLongClickListener(int viewId,
View.OnLongClickListener listener) {
View view = getView(viewId);
view.setOnLongClickListener(listener);
return this;
}
public CommonViewHolder setOnCheckedChangeListener(int viewId,
CompoundButton.OnCheckedChangeListener listener){
CheckBox view = getView(viewId);
view.setOnCheckedChangeListener(listener);
return this;
}
}
好了,我们的准备工作做完了,那么接下来就要看看如何在自己的Activity 中使用
详细的代码就不重复了。只写一下大概的实现;
for example:
//先实例化一个CommonAdapter<T Class>--注意此处
private CommonAdapter<DeviceEventInfo.EventList> commonAdapter;
private void initView(){
// 初始化常用组件
//实例化适配器,这块需要说明一下,原莱的listView BaseAdapter 是通过构造
//函数的方式传值的;而现在的CommonAdapter是通过泛型<>进行传数据封装和适配的;
//R.layout.item_envent:item 的布局;
//eventList: 数据集合 传入;
commonAdapter = new CommonAdapter<DeviceEventInfo.EventList>(context, eventList, R.layout.item_envent) {
@Override
public void convert(CommonViewHolder holder, DeviceEventInfo.EventList eventList) {
holder.setText(R.id.event_title_tv, eventList.event_name);
}
};
// 事件回掉监听;
commonAdapter.setOnItemClickListener(new CommonAdapter.OnItemClickListener<DeviceEventInfo.EventList>() {
@Override
public void onItemClick(View view, RecyclerView.ViewHolder holder, DeviceEventInfo.EventList eventBean, int position) {
if (eventBean.trigger_parameter != null && eventBean.trigger_parameter.size() > 0) {
triggerParameterList = eventBean.trigger_parameter;
Intent intent = new Intent(context, TriggerParameterActivity.class);
intent.putExtra("triggerParameterList", (Serializable) eventBean);
if (deviceBean != null) intent.putExtra("deviceBean", (Serializable) deviceBean);
DeviceConditionActivity.this.startActivity(intent);
finish();
} else {
Map<String, String> data = new HashMap<>();
data.put("event_id", eventBean.event_id);
data.put("eventName", eventBean.event_name);
data.put("step", "1");
data.put("eventType", "event");
data.put("trigger_type", eventBean.trigger_type);
data.put("device_type_id",deviceTypeId);
data.put("device_id",deviceBean.getDeviceId());
//选择了一个事件
SharedUtils.putInt("superApp", DeviceConditionActivity.this, "isSeletedEvent", 1);
EventBus.getDefault().post(new BaseEventMessage<Map<String, String>>("get_event_name", data));
finish();
}
}
@Override
public boolean onItemLongClick(View view, RecyclerView.ViewHolder holder, DeviceEventInfo.EventList eventBean, int position) {
return false;
}
});
rcyTrigger.setAdapter(commonAdapter);
}
最后一点就是:根据具体的业务规则,让itme显示不同的数据或者图片字段,或者是字体颜色因不同的业务规则;这就需要对具体的ViewHolder 进行判断;