Summary of some key points about layout compatibility of Material Design for Android applications

<!-- extend one of the  themes -->
<style name="" parent="">
  <!-- customize the color palette -->
  <item name="colorPrimary">@color/material_blue_500</item>
  <item name="colorPrimaryDark">@color/material_blue_700</item>
  <item name="colorAccent">@color/material_green_A200</item>
</style>

dependencies {
  compile ':appcompat-v7:21.0.+'
  compile ':cardview-v7:21.0.+'
  compile ':recyclerview-v7:21.0.+'
}

// Check if we're running on Android 5.0 or higher
if (.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
  // Call some material design APIs here
} else {
  // Implement this feature without material design
}

import ; 
import ; 
import .; 
import .; 
import .; 
import ; 
import ; 
import ; 
 
public class RecyclerViewActivity extends Activity { 
  /*
    * Recyclerview provides these built-in layout managers:
    * linearlayoutmanager Displays vertical scrolling list or horizontal items. 
    * gridlayoutmanager is displayed in a grid item. 
    * staggeredgridlayoutmanager displays in the interleaved grid item. 
    * Custom layout manager, need to inherit classes. 
    *
    * Animation when add/remove items is enabled by default. 
    * Customizing these animations requires inheritance and implementing ()
    */ 
   private RecyclerView mRecyclerView; 
   private  mAdapter; 
   private  mLayoutManager; 
   private String[] myDataset; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    (savedInstanceState); 
     
    setContentView(.recycler_view); 
    mRecyclerView = (RecyclerView) findViewById(.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 
    (true); 
 
    // use a linear layout manager 
//    mLayoutManager = new LinearLayoutManager(this); 
     
//    mLayoutManager = new GridLayoutManager(this, 3, , true); 
    //true means that the layout content is reversed    mLayoutManager = new GridLayoutManager(this, 3, , false); 
    //HORIZONTAL Scroll horizontally display content VERTICAL Portrait//    mLayoutManager = new GridLayoutManager(this, 3, , false); 
     
    //The direction also indicates the scrolling direction. In the example, the data at the beginning of the horizontal direction is interleaved a little, and the vertical direction is not interleaved.//    mLayoutManager = new StaggeredGridLayoutManager(3, ); 
//    mLayoutManager = new StaggeredGridLayoutManager(4, ); 
     
    (mLayoutManager); 
// (new MyLayoutMnager()); // The data is not displayed, and something may need to be rewrited.  . 
    // specify an adapter (see also next example) 
    
    setDatas(); 
    mAdapter = new MyAdapter(myDataset); 
    (mAdapter); 
  } 
   
  private void setDatas() { 
    int len = 200; 
    myDataset = new String[len]; 
    for (int i = 0; i < len; i++) { 
      switch (i%3) { 
      case 0: 
        myDataset[i] = "China" + i; 
        break; 
      case 1: 
        myDataset[i] = "USA" + i; 
        break; 
      case 2: 
        myDataset[i] = "Australia" + i; 
        break; 
      } 
    } 
  } 
   
  class MyLayoutMnager extends  { 
 
    @Override 
    public LayoutParams generateDefaultLayoutParams() { 
      LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 
       = 5; 
      return params; 
    } 
  } 
   
  class MyAdapter extends <ViewHolder> { 
    private String[] mDataset; 
 
    // Provide a reference to the views for each data item 
    // Complex data items may need more than one view per item, and 
    // you provide access to all the views for a data item in a view holder 
 
    // Provide a suitable constructor (depends on the kind of dataset) 
    public MyAdapter(String[] myDataset) { 
      mDataset = myDataset; 
    } 
 
    // Create new views (invoked by the layout manager) 
    @Override 
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
      // create a new view 
      TextView tv = (TextView) (()) 
          .inflate(.my_text_view, parent, false); 
      // set the view's size, margins, paddings and layout parameters 
      //... 
      ViewHolder vh = new ViewHolder(tv); //Build a ViewHolder      return vh; 
    } 
 
    // Replace the contents of a view (invoked by the layout manager) 
    @Override 
    public void onBindViewHolder(ViewHolder holder, int position) { 
      // - get element from your dataset at this position 
      // - replace the contents of the view with that element 
      (mDataset[position]); 
 
    } 
 
    // Return the size of your dataset (invoked by the layout manager) 
    @Override 
    public int getItemCount() { 
      return ; 
    } 
  } 
   
  static class ViewHolder extends  { 
    // each data item is just a string in this case 
    public TextView mTextView; 
    public ViewHolder(TextView v) { 
      super(v); 
      mTextView = v; 
    } 
  } 
}