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：
image.png
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));
}
}
步骤3、4、5、6如下：
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()
image.png
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
否则会报以下错
java.lang.IllegalArgumentException: Item at position 0 requires 3 spans but GridLayoutManager has only 2 spans.
