00-Unit_Common综述-RecyclerView封装
程序员文章站
2022-04-24 16:51:46
自学安卓也有一年的时间了，与代码相伴的日子里，苦乐共存。能坚持到现在确实已见到了“往日所未曾见证的风采”。今2018年4月2日，决定用一个案例：Unit_Common，把安卓基础的知识进行串联，形成模块化的总结性测试案例，一方面是对自己的总结，在总结中温故知新。另一方面通过博客，和众多开发爱好者进行... ......
自学安卓也有一年的时间了，与代码相伴的日子里，苦乐共存。能坚持到现在确实已见到了“往日所未曾见证的风采”。今2018年4月24日，决定用一个案例：Unit_Common，把安卓基础的知识进行串联，形成模块化的总结性测试案例，一方面是对自己的总结，在总结中温故知新。另一方面通过博客，和众多开发爱好者进行知识分享，希望可以帮助到一些新入安卓的人。
本项目通过一个RecyclerView进行模块的划分，点击item进入相应模块。所以本篇先用RecyclerView将整个案例的框架搭建出来，这篇对新手可能比较难以理解，但并不影响学习后面的简单知识。
为了方便查看将每个模块的名称和图片展示在RecyclerView的item上：
1 package top.toly.www.unit_common.bean;
2
3 /**
4 * 作者：张风捷特烈
5 * 时间：2018/4/10:14:55
6 * 邮箱：1981462002@qq.com
7 * 说明：每个界面的bean对象 图片+名称
8 */
9 public class ItemBean {
10
11 private String name;
12 private int ResId;
13
14 public ItemBean(String name, int resId) {
15 this.name = name;
16 ResId = resId;
17 }
18
19 public String getName() {
20 return name;
21 }
22
23 public void setName(String name) {
24 this.name = name;
25 }
26
27 public int getResId() {
28 return ResId;
29 }
30
31 public void setResId(int resId) {
32 ResId = resId;
33 }
34 }
Activity_Home_RV 我们需要关注的是OnRvItemClick方法：通过位置打开模块。 setItemsData方法设置数据
1 注：笔者为避免寻找id的麻烦，使用了ButterKnife
2 依赖：implementation 'com.jakewharton:butterknife:7.0.1'
3 混淆：#butterknife
4 -keep class butterknife.** { *; }
5 -dontwarn butterknife.internal.**
6 -keep class **$$ViewBinder { *; }
7 -keepclasseswithmembernames class * {
8 @butterknife.* <fields>;
9 }
10 -keepclasseswithmembernames class * {
11 @butterknife.* <methods>;
12 }
1 package top.toly.www.unit_common.home;
2
3 import android.content.Intent;
4 import android.os.Bundle;
5 import android.support.v7.app.AppCompatActivity;
6 import android.support.v7.widget.RecyclerView;
7 import android.view.View;
8
9 import java.util.ArrayList;
10 import java.util.List;
11
12 import butterknife.Bind;
13 import butterknife.ButterKnife;
14 import top.toly.www.unit_common.R;
15 import top.toly.www.unit_common.activity.MainActivity;
16 import top.toly.www.unit_common.bean.ItemBean;
17 import utils.ev.recyclerview.MyRVAdapter;
18 import utils.ev.recyclerview.MyRVHolder;
19 import utils.ui.UIUtils;
20
21 public class Activity_Home_RV extends AppCompatActivity {
22
23 @Bind(R.id.recyclerview)
24 RecyclerView mRecyclerview;
25 private List<ItemBean> mItems;//itemBean的集合
26
27 @Override
28 protected void onCreate(Bundle savedInstanceState) {
29 super.onCreate(savedInstanceState);
30 setContentView(R.layout.activity_home_rv);
31 ButterKnife.bind(this);
32
33 setItemsData();//为item设置数据
34 initRV();//初始化RecyclerView
35
36 }
37
38 private void initRV() {
39 // 注：笔者已对RecyclerView进行封装，以下几行就搞定RecyclerView的简单使用，封装代码见下
40 UIUtils.setStyle4RV(mRecyclerview, 3, UIUtils.GRIDVIEW, this);//设置类型
41 MyRVAdapter<ItemBean> rvAdapter = new MyRVAdapter<ItemBean>(mItems, R.layout.rv_item_home) {
42 @Override
43 public void setDatas(MyRVHolder holder, ItemBean data, int position) {
44 holder.setText(R.id.tv_title, data.getName())
45 .setImageViewRes(R.id.iv_icon, data.getResId());
46 }
47 };
48
49 mRecyclerview.setAdapter(rvAdapter);
50 rvAdapter.setOnRvItemClickListener(new MyRVAdapter.OnRvItemClickListener() {
51 @Override
52 public void OnRvItemClick(View v, int pos) {
53 switch (pos) {
54 case 0:
55 startActivity(new Intent(Activity_Home_RV.this, MainActivity.class));
56 break;
57 }
58 }
59 });
60 }
61
62 /**
63 * 为item设置数据
64 *
65 * @return
66 */
67
68 public List<ItemBean> setItemsData() {
69 mItems = new ArrayList<>();
70 mItems.add(new ItemBean("test", R.drawable.ic_launcher_background));
71 mItems.add(new ItemBean("test1", R.drawable.ic_launcher_background));
72 return mItems;
73 }
74
75 }
布局：
activity_home_rv.xml：
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout 3 xmlns:android="http://schemas.android.com/apk/res/android" 4 xmlns:tools="http://schemas.android.com/tools" 5 android:layout_width="match_parent" 6 android:layout_height="match_parent"> 7 8 <android.support.v7.widget.RecyclerView 9 android:id="@+id/recyclerview" 10 android:layout_width="match_parent" 11 android:layout_height="wrap_content"/> 12 13 </RelativeLayout>
rv_item_home.xml:
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="wrap_content" 5 android:padding="5dp"> 6 7 <ImageView 8 android:id="@+id/iv_icon" 9 android:layout_width="50dp" 10 android:layout_height="50dp" 11 android:src="@drawable/ic_launcher_background" /> 12 13 <TextView 14 android:id="@+id/tv_title" 15 android:layout_width="match_parent" 16 android:layout_height="wrap_content" 17 android:layout_marginLeft="3dp" 18 android:layout_toRightOf="@+id/iv_icon" 19 android:layout_centerInParent="true" 20 android:text="Content" 21 android:textAllCaps="false" 22 android:textColor="#000000" /> 23 </RelativeLayout>
效果如下：随着mItems数量增加，RecyclerView也会增加
下面是笔者封装的代码：虽然比较多，但拷贝进去就能用。好了，综述就到这里。
对RecyclerView进行封装：两个类MyRVHolder和MyRVAdapter
1 package utils.ev.recyclerview;
2
3 import android.graphics.Bitmap;
4 import android.support.v7.widget.RecyclerView;
5 import android.util.SparseArray;
6 import android.view.View;
7 import android.widget.ImageView;
8 import android.widget.TextView;
9
10 import com.bumptech.glide.Glide;
11 import com.bumptech.glide.load.engine.DiskCacheStrategy;
12
13 import utils.ui.UIUtils;
14
15 /**
16 * 作者：张风捷特烈
17 * 时间：2018/4/10:14:22
18 * 邮箱：1981462002@qq.com
19 * 说明：View的持有人
20 */
21 public class MyRVHolder extends RecyclerView.ViewHolder {
22
23 //键值对中键是int类型使用SparseArray比map更好
24 private SparseArray<View> mViews;//持有的所有View集合
25 private View mItemView;//Item的
26
27 public MyRVHolder(View itemView) {
28
29 super(itemView);
30 mItemView = itemView;
31 mViews = new SparseArray<>();
32 }
33
34 /**
35 * 获取pos
36 *
37 * @return
38 */
39 public int getPos() {
40 return this.getLayoutPosition();
41 }
42
43 /**
44 * 通过viewId获取控件
45 *
46 * @param viewId
47 * @param <T>
48 * @return
49 */
50 public <T extends View> T getView(int viewId) {
51 View view = mViews.get(viewId);
52 if (view == null) {
53 view = mItemView.findViewById(viewId);
54 mViews.put(viewId, view);//以id为键，view为值
55 }
56 return (T) view;
57 }
58
59 public View getItemView() {
60 return mItemView;
61 }
62
63 /**
64 * 设置item背景颜色
65 */
66 public MyRVHolder setColor(int color) {
67 mItemView.setBackgroundColor(color);
68 return this;
69 }
70
71 /**
72 * 设置TextView文本方法
73 *
74 * @param viewId
75 * @param text
76 * @return
77 */
78 public MyRVHolder setText(int viewId, String text) {
79 TextView view = getView(viewId);
80 view.setText(text);
81 return this;
82 }
83
84 /**
85 * 通过资源id设置ImageView图片
86 * @param viewId
87 * @param resId
88 * @return
89 */
90 public MyRVHolder setImageViewRes(int viewId, int resId) {
91 ImageView view = getView(viewId);
92 view.setImageResource(resId);
93 return this;
94 }
95
96 /**
97 * 通过Bitmap设置ImageView图片
98 * @param viewId
99 * @param bitmap
100 * @return
101 */
102 public MyRVHolder setImageViewBitmap(int viewId, Bitmap bitmap) {
103 ImageView view = getView(viewId);
104 view.setImageBitmap(bitmap);
105 return this;
106 }
107
108 /**
109 * 通过url设置图片
110 * @param viewId
111 * @param url
112 * @return
113 */
114 public MyRVHolder setImageViewUrl(int viewId, String url) {
115 ImageView view = getView(viewId);
116 //此处使用Glide进行Url类型图片的加载,如果未添加Glide依赖会报错
117 //依赖： implementation 'com.github.bumptech.glide:glide:3.7.0'
118 Glide.with(UIUtils.getContext())
119 .load(url)
120 .skipMemoryCache(false)
121 .diskCacheStrategy(DiskCacheStrategy.SOURCE)
122 .into(view);
123
124 return this;
125 }
126
127 /////////////////////可继续拓展完善,添加更多方法//////////////////////
128 }
1 package utils.ev.recyclerview;
2
3 import android.support.v7.widget.RecyclerView;
4 import android.view.View;
5 import android.view.ViewGroup;
6
7 import java.util.List;
8
9 import utils.ui.UIUtils;
10
11 /**
12 * 作者：张风捷特烈
13 * 时间：2018/4/10:14:28
14 * 邮箱：1981462002@qq.com
15 * 说明：RecyclerView的Adapter封装类
16 */
17 public abstract class MyRVAdapter<T> extends RecyclerView.Adapter<MyRVHolder> {
18 protected List<T> mDatas;
19 protected int mItemId;
20 private View mItemView;
21
22 public MyRVAdapter(List<T> datas, int itemId) {
23 mDatas = datas;
24 mItemId = itemId;
25 }
26
27 @Override
28 public MyRVHolder onCreateViewHolder(ViewGroup parent, int viewType) {
29 mItemView = UIUtils.inflate(mItemId);
30 final MyRVHolder myRVHolder = new MyRVHolder(mItemView);
31 //点击事件方式
32 mItemView.setOnClickListener(new View.OnClickListener() {
33 @Override
34 public void onClick(View v) {//使用回调实现点击监听
35 if (mOnRvItemClickListener != null) {
36 mOnRvItemClickListener.OnRvItemClick(v, myRVHolder.getPos());
37
38 }
39 }
40 });
41
42 return myRVHolder;
43 }
44
45 @Override
46 public void onBindViewHolder(MyRVHolder holder, int position) {
47
48 setDatas(holder, mDatas.get(position), position);
49
50 }
51
52 @Override
53 public int getItemCount() {
54 return mDatas.size();
55 }
56
57 /**
58 * 抽象方法,通过holder可对各控件进行操作
59 *
60 * @param holder View的持有人
61 * @param data 数据
62 * @param position 点击位置
63 */
64 public abstract void setDatas(MyRVHolder holder, T data, int position);
65
66 ///////////////////////////////////////////////////////////
67
68 /**
69 * 添加item
70 *
71 * @param i
72 * @param aNew
73 */
74 public void addData(int i, T aNew) {
75 mDatas.add(i, aNew);
76 notifyItemInserted(i);//刷新数据
77 }
78
79 /**
80 * 删除item
81 *
82 * @param i
83 */
84 public void deleteData(int i) {
85 mDatas.remove(i);
86 notifyItemRemoved(i);//刷新数据
87 }
88
89 public View getItemView() {
90 return mItemView;
91 }
92
93 /////////////////为RecyclerView设置点击监听接口/////////////////////////
94 /**
95 * 为RecyclerView设置点击监听接口
96 */
97 public interface OnRvItemClickListener {
98 void OnRvItemClick(View v, int pos);//item被点击的时候回调方法
99 }
100
101 /**
102 * 声明监听器接口对象
103 */
104 private OnRvItemClickListener mOnRvItemClickListener;
105
106 /**
107 * 设置RecyclerView某个的监听方法
108 *
109 * @param onRvItemClickListener
110 */
111 public void setOnRvItemClickListener(OnRvItemClickListener onRvItemClickListener) {
112 mOnRvItemClickListener = onRvItemClickListener;
113 }
114 }
这样可以使用了，不过为了添加分割线，还有免去写一些初始化的设置方法，把其封装在我的UiUtils中，静态方法如下：
1 ////////////////////////设置RecyclerView/////////////////////////////////////////
2 public static final int GRIDVIEW = 0;
3 public static final int LISTVIEW = 1;
4 public static final int PULL = 2;
5
6 /**
7 *
8 * @param rv RecyclerView
9 * @param count count 数量 LISTVIEW可随意
10 * @param style 模式 GRIDVIEW LISTVIEW PULL
11 * @param ctx 上下文
12 */
13 public static GridLayoutManager setStyle4RV(RecyclerView rv, int count, int style,Context ctx) {
14 switch (style) {
15 case GRIDVIEW://GridView类型
16 rv.addItemDecoration(new MyDividerItemDecoration(ctx));//设置分割线
17 GridLayoutManager gridLayoutManager = new GridLayoutManager(getContext(), count, GridLayoutManager.VERTICAL, false);
18 rv.setLayoutManager(gridLayoutManager);
19 return gridLayoutManager;
20 case LISTVIEW://ListView类型
21 rv.addItemDecoration(new SampleDivider(ctx));
22 rv.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
23 return null;
24 case PULL://瀑布流类型
25 rv.addItemDecoration(new MyDividerItemDecoration(ctx));
26 rv.setLayoutManager(new StaggeredGridLayoutManager(count, StaggeredGridLayoutManager.VERTICAL));
27 return null;
28 }
29 return null;
30 }
MyDividerItemDecoration 分割线：
1 package utils.ev.recyclerview;
2
3 import android.content.Context;
4 import android.content.res.TypedArray;
5 import android.graphics.Canvas;
6 import android.graphics.Rect;
7 import android.graphics.drawable.Drawable;
8 import android.support.v7.widget.GridLayoutManager;
9 import android.support.v7.widget.OrientationHelper;
10 import android.support.v7.widget.RecyclerView;
11 import android.view.View;
12
13
14 public class MyDividerItemDecoration extends RecyclerView.ItemDecoration {
15
16 private static final int[] ATTRS = new int[]{
17 android.R.attr.listDivider
18 };
19
20 /**
21 * 用于绘制间隔样式
22 */
23 private Drawable mDivider;
24
25 public MyDividerItemDecoration(Context context) {
26 // 获取默认主题的属性
27 final TypedArray a = context.obtainStyledAttributes(ATTRS);
28 mDivider = a.getDrawable(0);
29 a.recycle();
30 }
31
32
33 @Override
34 public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
35 // 绘制间隔，每一个item，绘制右边和下方间隔样式
36 int childCount = parent.getChildCount();
37 int spanCount = ((GridLayoutManager)parent.getLayoutManager()).getSpanCount();
38 int orientation = ((GridLayoutManager)parent.getLayoutManager()).getOrientation();
39 boolean isDrawHorizontalDivider = true;
40 boolean isDrawVerticalDivider = true;
41 int extra = childCount % spanCount;
42 extra = extra == 0 ? spanCount : extra;
43 for(int i = 0; i < childCount; i++) {
44 isDrawVerticalDivider = true;
45 isDrawHorizontalDivider = true;
46 // 如果是竖直方向，最右边一列不绘制竖直方向的间隔
47 if(orientation == OrientationHelper.VERTICAL && (i + 1) % spanCount == 0) {
48 isDrawVerticalDivider = false;
49 }
50
51 // 如果是竖直方向，最后一行不绘制水平方向间隔
52 if(orientation == OrientationHelper.VERTICAL && i >= childCount - extra) {
53 isDrawHorizontalDivider = false;
54 }
55
56 // 如果是水平方向，最下面一行不绘制水平方向的间隔
57 if(orientation == OrientationHelper.HORIZONTAL && (i + 1) % spanCount == 0) {
58 isDrawHorizontalDivider = false;
59 }
60
61 // 如果是水平方向，最后一列不绘制竖直方向间隔
62 if(orientation == OrientationHelper.HORIZONTAL && i >= childCount - extra) {
63 isDrawVerticalDivider = false;
64 }
65
66 if(isDrawHorizontalDivider) {
67 drawHorizontalDivider(c, parent, i);
68 }
69
70 if(isDrawVerticalDivider) {
71 drawVerticalDivider(c, parent, i);
72 }
73 }
74 }
75
76 @Override
77 public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
78 int spanCount = ((GridLayoutManager) parent.getLayoutManager()).getSpanCount();
79 int orientation = ((GridLayoutManager)parent.getLayoutManager()).getOrientation();
80 int position = parent.getChildLayoutPosition(view);
81 if(orientation == OrientationHelper.VERTICAL && (position + 1) % spanCount == 0) {
82 outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
83 return;
84 }
85
86 if(orientation == OrientationHelper.HORIZONTAL && (position + 1) % spanCount == 0) {
87 outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
88 return;
89 }
90
91 outRect.set(0, 0, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight());
92 }
93
94 /**
95 * 绘制竖直间隔线
96 *
97 * @param canvas
98 * @param parent
99 * 父布局，RecyclerView
100 * @param position
101 * irem在父布局中所在的位置
102 */
103 private void drawVerticalDivider(Canvas canvas, RecyclerView parent, int position) {
104 final View child = parent.getChildAt(position);
105 final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
106 .getLayoutParams();
107 final int top = child.getTop() - params.topMargin;
108 final int bottom = child.getBottom() + params.bottomMargin + mDivider.getIntrinsicHeight();
109 final int left = child.getRight() + params.rightMargin;
110 final int right = left + mDivider.getIntrinsicWidth();
111 mDivider.setBounds(left, top, right, bottom);
112 mDivider.draw(canvas);
113 }
114
115 /**
116 * 绘制水平间隔线
117 *
118 * @param canvas
119 * @param parent
120 * 父布局，RecyclerView
121 * @param position
122 * item在父布局中所在的位置
123 */
124 private void drawHorizontalDivider(Canvas canvas, RecyclerView parent, int position) {
125 final View child = parent.getChildAt(position);
126 final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
127 .getLayoutParams();
128 final int top = child.getBottom() + params.bottomMargin;
129 final int bottom = top + mDivider.getIntrinsicHeight();
130 final int left = child.getLeft() - params.leftMargin;
131 final int right = child.getRight() + params.rightMargin + mDivider.getIntrinsicWidth();
132 mDivider.setBounds(left, top, right, bottom);
133 mDivider.draw(canvas);
134 }
135 }
上一篇： 小岛工作室推官方手机壳：粉丝力顶