RecyclerView和SwipeRefreshLayout的使用

RecyclerView##

RecyclerView支持库包含在sdk目录下，具体在 sdk\extras\android\support\v7\recyclerview，在Android studio 中直接在 build 文件中添加如下语句即可使用

compile 'com.android.support:recyclerview-v7:23.+'

当然，直接在app目录下的libs中添加RecyclerView的JAR包，并 Add As Library 就可以使用了。

• 在 main_layout.xml文件中添加RecyclerView控件

• 在Activity中设置一些关键属性

recyclerView =(RecyclerView)findViewById(R.id.recycleview);

//如果可以确定每个Item的高度固定，选用这个属性可以提高性能
recyclerView.setHasFixedSize(true);

//使用默认的LayoutManager
recyclerView.setLayoutManager(new LinearLayoutManager(this));

//使用默认的动画效果
recyclerView.setItemAnimator(new DefaultItemAnimator());

//为RecycleView设置Adapter
recyclerView.setAdapter(adapter);

关于更多这些属性的介绍，可以参考

http://blog.iderzheng.com/first-date-with-recyclerview/

想要使用RecyclerView就必须要涉及到Adapter的创建，为了响应Item的点击事件，首先定义好两个接口，以响应点击事件和长点击事件。

public interface LongClick {
    public void onItemClick(View view,int position);
}

public interface ShortClick {
    public void onItemClick(View view,int position);
}

自定义ViewHolder供Adapter高效获取每个 Item视图，因为ViewHolder能够直接获取到Item，所以将点击事件写在这里

public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnLongClickListener {

    public TextView textView;
    private LongClick longClick;
    private ShortClick shortClick;

    public MyViewHolder(View itemView,LongClick longClick,ShortClick shortClick) {
        super(itemView);

        textView = (TextView) itemView.findViewById(R.id.cv_text);
        this.longClick = longClick;
        this.shortClick = shortClick;

        textView.setOnClickListener(this);
        textView.setOnLongClickListener(this);
    }

    @Override
    public void onClick(View view) {

        if (shortClick != null){

            shortClick.onItemClick(view,getPosition());
        }
    }

    @Override
    public boolean onLongClick(View view) {

        if (longClick != null){

            longClick.onItemClick(view,getPosition());
        }
        return true;
    }
}

自定义Adapter要继承RecyclerView.Adapter,并实现其下的三个Implements methods

 -  public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
 -  public void onBindViewHolder(MyViewHolder holder, int position)
 -  public int getItemCount()

由此，Adapter写法可以为

public class MyAdapter extends RecyclerView.Adapter{

    private List data;
    private ShortClick shortClick;
    private LongClick longClick;

    public MyAdapter(List data){
        this.data = data;
    }
    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview_layout,parent,false);
        MyViewHolder holder = new MyViewHolder(view,longClick,shortClick);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        holder.textView.setText(data.get(position));
    }

    @Override
    public int getItemCount() {
        return data.size();
    }

    public void setOnItemClickListener(ShortClick shortClick){
        this.shortClick = shortClick;
    }

    public void serOnItemLongClickListener(LongClick longClick){

        this.longClick = longClick;
    }
}

之后再Activity就可以定义Adapter，并实现点击事件和长点击事件的方法

adapter = new MyAdapter(data);
adapter.serOnItemLongClickListener(new LongClick() {
      @Override
      public void onItemLongClick(View view, int position) {
            data.remove(position);
            adapter.notifyItemRemoved(position);
         }
      });
adapter.setOnItemClickListener(new ShortClick() {
          @Override
          public void onItemClick(View view, int position) {
              Snackbar snackbar =Snackbar.make(recyclerView,data.get(position),Snackbar.LENGTH_LONG);
              snackbar.show();
            }
        });
recyclerView.setAdapter(adapter);

CardView的简单使用

在 build文件中添加

compile 'com.android.support:cardview-v7:23.+'

就可以使用CardView了

• contentPadding 属性可以设置内容与内边距
• cardCornerRadius 属性可以设置圆角的大小
• cardElevation 属性可以设置阴影的大小
• cardBackgroundColor 属性可以设置卡片的背景颜色

SwipeRefreshLayout的简单使用

SwipeRefreshLayout 有四个基本方法可供设置

1. setOnRefreshListener(OnRefreshListener listener) 设置下拉监听，当用户下拉的时候会去执行回调
2. setColorSchemeColors(int... colors) 设置 进度条的颜色变化，最多可以设置4种颜色
3. setProgressViewOffset(boolean scale, int start, int end) 调整进度条距离屏幕顶部的距离
4. setRefreshing(boolean refreshing) 设置SwipeRefreshLayout当前是否处于刷新状态，一般是在请求数据的时候设置为true，在数据被加载到View中后，设置为false。

下面就到Activity去获取并设置这些方法

swipeRefreshLayout = (SwipeRefreshLayout)findViewById(R.id.swipeRefresh);

        swipeRefreshLayout.setColorSchemeResources(R.color.colorPrimary,R.color.colorAccent,R.color.colorPrimaryDark);
        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                refreshContent();
            }
        });




private void refreshContent() {

        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {

                data.add("Hello");
                adapter.notifyItemInserted(data.size());
                swipeRefreshLayout.setRefreshing(false);//用于将刷新的旋转按钮隐藏，如果不调用该条语句，刷新旋转按钮会一直存在
            }
        },3000);
   }