RecyclerView包含多种布局实现_recyclerview多种布局

内容：同一个RecyclerView包含多种布局。本例设置了三个不同的布局样式，都在同一个RecyclerView中展示出来。

尾末简要介绍了下GridLayoutManager的setSpanSizeLookup()方法

效果如下：

步骤：

1、定义三种不同布局，用于填充到RecyclerView中

2、加入RecyclerView控件，设置好adapter和数据

3、新建类继承RecyclerView.Adapter<RecyclerView.ViewHolder>，注意：<RecyclerView.ViewHolder>，此处不是具体的viewHoler

4、重写getItemViewType(int position)，这里设置好视图类型，后面会根据此处的返回类型去加载对应的布局

5、onCreateViewHolder(ViewGroup parent, int viewType)根据viewType填充不同布局

6、onBindViewHolder(RecyclerView.ViewHolder holder, final int position)根据holder类型设置数据填充

代码如下：

1、填充布局不贴出，就一个TextView宽高颜色不一样

2、加入RecyclerView控件，设置好adapter和数据

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

public class MainActivity extends AppCompatActivity{
 
	private String[] mStrings = {"1", "2", "3", "3", "2", "1", "1", "3", "2", "3", "1", "3"};
	private List<String> data = new ArrayList<>();
 
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
 
		data = Arrays.asList(mStrings);
		RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
		recyclerView.setLayoutManager(new LinearLayoutManager(this));
		recyclerView.setAdapter(new MyAdapter(this, data));
	}
}

3、4、5、6

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
 
	private Context mContext;
	private List<String> content;
 
	public MyAdapter(List<String> content, Context context) {
		this.content = content;
		mContext = context;
	}
 
	public MyAdapter(Context context, List<String> content) {
		mContext = context;
		this.content = content;
	}
 
	/**
	 *	根据position位置(或者自己需求)设置不同视图类型
	 */
	@Override
	public int getItemViewType(int position) {
		switch (content.get(position)) {
			case "1":
				return 1;
			case "2":
				return 2;
			default:
				return 3;
		}
	}
 
	/**
	 * @param parent
	 * @param viewType
	 * @return 根据viewType设置不同的布局  从而实现多布局
	 */
	@Override
	public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
		RecyclerView.ViewHolder viewHolder;
		View view;
 
		//根据不同的类型加载对应的布局
		switch (viewType) {
			case 1:
				view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_1, parent, false);
				viewHolder = new FirstHolder(view);
				return viewHolder;
			case 2:
				view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_2, parent,false);
				viewHolder = new SecondHolder(view);
				return viewHolder;
			case 3:
				view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_3, parent,false);
				viewHolder = new ThirdHolder(view);
				return viewHolder;
			default:
				return null;
		}
	}
 
	/**
	 * @param holder
	 * @param position 根据holder设置不同的数据
	 */
	@Override
	public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
		if (holder instanceof FirstHolder) {
			((FirstHolder) holder).mTextView.setText("FirstHolder");
			((FirstHolder) holder).mTextView.setOnClickListener(new View.OnClickListener() {
				@Override
				public void onClick(View v) {
					toast("FirstHolder pos:" + position);
				}
			});
		} else if (holder instanceof SecondHolder) {
			((SecondHolder) holder).mTextView.setText("SecondHolder");
			((SecondHolder) holder).mTextView.setOnClickListener(new View.OnClickListener() {
				@Override
				public void onClick(View v) {
					toast("SecondHolder pos:" + position);
				}
			});
		}else if (holder instanceof ThirdHolder) {
			((ThirdHolder) holder).mTextView.setText("ThirdHolder");
			((ThirdHolder) holder).mTextView.setOnClickListener(new View.OnClickListener() {
				@Override
				public void onClick(View v) {
					toast("ThirdHolder pos:" + position);
				}
			});
		}
 
	}
 
	@Override
	public int getItemCount() {
		return content.size();
	}
 
	private void toast(String string) {
		Toast.makeText(mContext, string, Toast.LENGTH_SHORT).show();
	}
 
	public static class FirstHolder extends RecyclerView.ViewHolder {
		public TextView mTextView;
 
		public FirstHolder(View itemView) {
			super(itemView);
			mTextView = itemView.findViewById(R.id.tv_1);
		}
	}
 
	public static class SecondHolder extends RecyclerView.ViewHolder{
		public TextView mTextView;
 
		public SecondHolder(View itemView) {
			super(itemView);
			mTextView = itemView.findViewById(R.id.tv_2);
		}
	}
 
	public static class ThirdHolder extends RecyclerView.ViewHolder{
		public TextView mTextView;
 
		public ThirdHolder(View itemView) {
			super(itemView);
			mTextView = itemView.findViewById(R.id.tv_3);
		}
	}
}

Kotlin代码如下：

class MainActivity : AppCompatActivity() {
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
 
        val data = listOf<String>("1", "2", "3", "3", "2", "1", "1", "3", "2", "3", "1", "3")
        recyclerView.layoutManager = LinearLayoutManager(this)
        recyclerView.adapter = MyAdapter(this, data)
    }
}

class MyAdapter(private val context: Context, private val data: List<String>): RecyclerView.Adapter<RecyclerView.ViewHolder>() {
 
    override fun getItemViewType(position: Int): Int {
        when (data[position]) {
            "1" -> return 1
            "2" -> return 2
            else -> return 3
        }
    }
 
    override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): RecyclerView.ViewHolder? {
        val viewHolder: RecyclerView.ViewHolder
        val view: View
 
        //根据不同的类型加载对应的布局
        when (viewType) {
            1 -> {
                view = LayoutInflater.from(parent?.getContext()).inflate(R.layout.item_1, parent, false)
                viewHolder = FirstHolder(view)
                return viewHolder
            }
            2 -> {
                view = LayoutInflater.from(parent?.getContext()).inflate(R.layout.item_2, parent, false)
                viewHolder = SecondHolder(view)
                return viewHolder
            }
            3 -> {
                view = LayoutInflater.from(parent?.getContext()).inflate(R.layout.item_3, parent, false)
                viewHolder = ThirdHolder(view)
                return viewHolder
            }
            else -> return null
        }
    }
 
 
    override fun getItemCount(): Int {
        return data.size
    }
 
    override fun onBindViewHolder(holder: RecyclerView.ViewHolder?, position: Int) {
        if (holder is FirstHolder) {
            holder.mTextView.text = "FirstHolder"
            holder.mTextView.setOnClickListener { toast("FirstHolder pos:$position") }
        } else if (holder is SecondHolder) {
            holder.mTextView.text = "SecondHolder"
            holder.mTextView.setOnClickListener { toast("SecondHolder pos:$position") }
        } else if (holder is ThirdHolder) {
            holder.mTextView.text = "ThirdHolder"
            holder.mTextView.setOnClickListener { toast("ThirdHolder pos:$position") }
        }
    }
 
    private fun toast(string: String) {
        Toast.makeText(context, string, Toast.LENGTH_SHORT).show()
    }
 
    class FirstHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var mTextView: TextView
 
        init {
            mTextView = itemView.findViewById(R.id.tv_1)
        }
    }
 
    class SecondHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var mTextView: TextView
 
        init {
            mTextView = itemView.findViewById(R.id.tv_2)
        }
    }
 
    class ThirdHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var mTextView: TextView
 
        init {
            mTextView = itemView.findViewById(R.id.tv_3)
        }
    }
}

另一种是可以快速修改GridLayoutManager 布局 图片展示个数，通过设置setSpanSizeLookup()

代码如下：

  RecyclerView recylerview = (RecyclerView) findViewById(R.id.recylerview);
        GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 2);
        gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
            @Override
            public int getSpanSize(int i) {
                if (i == 0 || i == 3 ){
                    return 2;
                }else {
                    return 1;
                }
            }
        });
        recylerview.setLayoutManager(gridLayoutManager);
        GridAdapter adapter = new GridAdapter();
        recylerview.setAdapter(adapter);

注意：getSpanSize return 的数量不能大于 你 new GridLayoutManager(this, 2);的数量

否则会报错

java.lang.IllegalArgumentException: Item at position 0 requires 3 spans but GridLayoutManager has only 2 spans.