Android Material Design 详解(使用support v7兼容5.0以下系统)

ybw8 9年前

Material Design是Google在2014年的I/O大会上推出的全新设计语言。Material Design是基于Android 5.0(API level 21)的,兼容5.0以下的设备时需要使用版本号v21.0.0以上的support v7包中的appcpmpat,不过遗憾的是support包只支持Material Design的部分特性。使用eclipse或Android Studio进行开发时,直接在Android SDK Manager中将Extras->Android Support Library升级至最新版即可。目前最新版本为:

    com.android.support:appcompat-v7:21.0.3  

本文中示例程序使用minSdkVersion=14,即属于使用support包实现Material Design风格。

使用Material Design的步骤:

一、使用Material主题

1.创建一个Android应用,应用主题Theme.AppCompat(或其子主题,如Theme.AppCompat.Light.DarkActionBar)

2.自定义程序所使用的主题的某些属性,示例:

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">                <!--ActionBar的颜色-->                <item name="colorPrimary">@color/primary</item>                <!-- 随主题而改变的颜色(如CheckBox的颜色)-->                <item name="colorAccent">@color/accent</item>                <!--状态栏的颜色 (使用support包时似乎无效。)-->                <item name="colorPrimaryDark">@color/primary_dark</item>                        <!--ActionBar的样式-->                <item name="actionBarStyle">@style/AppTheme.ActionBarStyle</item>            </style>                    <style name="AppTheme.ActionBarStyle" parent="Widget.AppCompat.ActionBar.Solid">                <item name="android:titleTextStyle">@style/AppTheme.ActionBar.TitleTextStyle</item>            </style>                    <style name="AppTheme.ActionBar.TitleTextStyle" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">                <!--ActionBar标题文字颜色-->                <item name="android:textColor">@android:color/white</item>            </style>  

3.所有需要使用ActionBar的Activity必须继承自ActionBarActivity,因为即使使用了类似Theme.AppCompat.Light.DarkActionBar这样的主题,系统也不会自动添加ActionBar.
效果图:生气

  

相对于普通的ActionBar的变化:

(1)右侧三个小点的样式变了。(这个无所谓。。。)

(2)点击右侧三个小点(更多)时,下拉菜单不是从ActionBar的下面开始展开,而是直接从ActionBar之上开始!也许的确有办法把它改成旧的样式,不过查阅官方文档之后发现,Google对此的解释是:菜单是一个临时展现给用户的组件,因此应该悬浮在上面。也就是说,新的设计规则推荐的就是这种默认的样式。

二、使用RecyclerView

RecyclerView是Google在support v7包中提供的一个全新的组件。该组件是一个增强版的ListView,新特性:

1.提高了性能;

2.adapter中自动进行item复用,也就是说,以前的这种繁琐的写法不需要了:

    if (convertView == null) {                    convertView = LayoutInflater.from(context).inflate(R.layout.friends_item, parent, false);                    holder = new ViewHolder();                            holder.nameTV = (TextView) convertView.findViewById(R.id.friends_item_name);                    holder.phoneTV = (TextView) convertView.findViewById(R.id.friends_item_phone);                    convertView.setTag(holder);                } else {                    holder = (ViewHolder) convertView.getTag();                }  

3.预置了item的添加,删除,移动,修改时的动画,当且改动画也可以自定义。

效果图:

    

示例代码:

(1)主页面,获取到RecyclerView,设置adapter即可。

    RecyclerView mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);         // use this setting to improve performance if you know that changes         // in content do not change the layout size of the RecyclerView          mRecyclerView.setHasFixedSize(true);                 // use a linear layout manager        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));        //data         List<CityInfoBean> myDataset = new ArrayList<CityInfoBean>();                for (int i = 0; i < 50; i++) {                    CityInfoBean city = new CityInfoBean();                    city.setCityName("Tianjin-" + i);                    city.setCityPhone("022-" + i);                    city.setLocation("Asia_" + i);                            myDataset.add(city);                }                        RecyclerViewAdapter mAdapter = new RecyclerViewAdapter(this, myDataset);                mRecyclerView.setAdapter(mAdapter);                //RecyclerView doesn't has a 'OnItemClickListener' or 'OnItemLongClickListener' like ListView,         // so you should add the callback in adapter   

(2)adapter,RecyclerViewAdapter.java:
    public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {            private Context context;            private List<CityInfoBean> mDataset;                    public RecyclerViewAdapter(Context context, List<CityInfoBean> myDataset) {                this.context = context;                mDataset = myDataset;            }                    // Create new views (invoked by the layout manager)            @Override            public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {                View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_list_item, parent, false);                // set the view's size, margins, paddings and layout parameters                        final ViewHolder vh = new ViewHolder(v);                v.setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View v) {                        int position = vh.getPosition();                        Toast.makeText(v.getContext(), "Item click. Position:" +                                position, Toast.LENGTH_SHORT).show();                    }                });                        v.setOnLongClickListener(new View.OnLongClickListener() {                    @Override                    public boolean onLongClick(View v) {                        int position = vh.getPosition();        //                Toast.makeText(v.getContext(), "Item long click. Position:" +        //                        position, Toast.LENGTH_SHORT).show();                                showDialog(position);                                return true;                    }                });                        return vh;            }                    // Replace the contents of a view (invoked by the layout manager)            @Override            public void onBindViewHolder(ViewHolder holder, int position) {                holder.cityNameTV.setText(mDataset.get(position).getCityName());                holder.phoneTV.setText(mDataset.get(position).getCityPhone());                holder.addrTV.setText(mDataset.get(position).getLocation());            }                    @Override            public int getItemCount() {                return mDataset.size();            }                    private void showDialog(final int position) {                AlertDialog.Builder builder = new AlertDialog.Builder(context);                builder.setTitle("Choose operation");                        String[] dialogItems = new String[]{                        context.getString(R.string.delete_one_item),                        context.getString(R.string.add_one_item),                        context.getString(R.string.move_one_item),                        context.getString(R.string.change_one_item),                        context.getString(R.string.add_many_items),                };                builder.setItems(dialogItems, new DialogInterface.OnClickListener() {                    @Override                    public void onClick(DialogInterface dialog, int which) {                        switch (which) {                            case 0:                                //delete this item                                mDataset.remove(position);                                notifyItemRemoved(position);                                break;                            case 1:                                //add one item                                mDataset.add(position, new CityInfoBean("New City", "010", "Asia"));                                notifyItemInserted(position);                                break;                            case 2:                                //TODO remember to change the data set...                                //move one item to another position                                notifyItemMoved(position, position + 2);                                //May cause IndexOutOfBoundsException. This is just a demo!                                break;                            case 3:                                //change one item                                mDataset.get(position).setCityName("City name changed");                                notifyItemChanged(position);                                break;                            case 4:                                //add many items                                List<CityInfoBean> insertList = new ArrayList<CityInfoBean>();                                insertList.add(new CityInfoBean("New City 01", "010", "Asia"));                                insertList.add(new CityInfoBean("New City 02", "020", "America"));                                        mDataset.addAll(position, insertList);                                notifyItemRangeInserted(position, insertList.size());                                break;                            default:                                break;                        }                    }                });                        builder.create().show();            }                    public static class ViewHolder extends RecyclerView.ViewHolder {                public TextView cityNameTV, phoneTV, addrTV;                        public ViewHolder(View v) {                    super(v);                            cityNameTV = (TextView) v.findViewById(R.id.city_name);                    phoneTV = (TextView) v.findViewById(R.id.city_phone);                    addrTV = (TextView) v.findViewById(R.id.city_addr);                }            }        }  

(3)主页面布局文件:

recycler_layout.xml:

    <?xml version="1.0" encoding="utf-8"?>        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"            android:orientation="vertical"            android:layout_width="match_parent"            android:layout_height="match_parent">                    <android.support.v7.widget.RecyclerView                android:id="@+id/my_recycler_view"                android:scrollbars="vertical"                android:layout_width="match_parent"                android:layout_height="match_parent" />                </LinearLayout>  

二、使用CardView

CardView是Google在support v7包中提供了另一个全新组件,可以很方便的实现“卡片式布局”(具有投影/圆角 的立体效果)。CardView继承自FrameLayout,因此如果内部需要互不重叠的放置多个组件时,可能需要再嵌套一个LinearLayout 或RelativeLayout等。

效果图:

布局文件:

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"            android:layout_width="match_parent"            android:layout_height="wrap_content"            xmlns:card_view="http://schemas.android.com/apk/res-auto">                    <android.support.v7.widget.CardView                android:id="@+id/card_view"                android:layout_gravity="center"                android:layout_width="match_parent"                android:layout_height="200dp"                android:layout_margin="6dp"                card_view:cardCornerRadius="4dp"                card_view:cardBackgroundColor="@color/card_bg"                card_view:cardElevation="4dp">                        <LinearLayout                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:layout_margin="6dp"                    android:orientation="vertical">                            <ImageView                        android:layout_width="wrap_content"                        android:layout_height="wrap_content"                        android:contentDescription="@null"                        android:src="@drawable/ic_launcher" />                            <TextView                        android:id="@+id/info_text"                        android:layout_width="match_parent"                        android:layout_height="match_parent"                        android:textSize="18sp"                        android:text="@string/example_text" />                        </LinearLayout>                    </android.support.v7.widget.CardView>                </LinearLayout>  

属性解释:

cardCornerRadius:圆角大小;

cardElevation:投影的深度;

cardBackgroundColor:卡片的背景色。