使用RecyclerView创建动态列表:
当我们创建一个RecyclerView时。适配器我们必须指定ViewHolder，它将绑定到适配器。
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private String[] mDataset;
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public ViewHolder(TextView v) {
super(v);
mTextView = v;
}
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.some_layout, parent, false);
//findViewById...
ViewHolder vh = new ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.mTextView.setText(mDataset[position]);
}
@Override
public int getItemCount() {
return mDataset.length;
}
}
有可能创建多个视图类型的RecyclerView吗?
下面的代码不是伪代码。我已经测试过了，它对我很有效。
我想在我的recyclerview中创建一个headerview，然后在用户可以点击的标题下面显示一个图片列表。
我在我的代码中使用了一些开关，不知道这是否是最有效的方法，所以请随意给出您的评论:
public class ViewHolder extends RecyclerView.ViewHolder{
//These are the general elements in the RecyclerView
public TextView place;
public ImageView pics;
//This is the Header on the Recycler (viewType = 0)
public TextView name, description;
//This constructor would switch what to findViewBy according to the type of viewType
public ViewHolder(View v, int viewType) {
super(v);
if (viewType == 0) {
name = (TextView) v.findViewById(R.id.name);
decsription = (TextView) v.findViewById(R.id.description);
} else if (viewType == 1) {
place = (TextView) v.findViewById(R.id.place);
pics = (ImageView) v.findViewById(R.id.pics);
}
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType)
{
View v;
ViewHolder vh;
// create a new view
switch (viewType) {
case 0: //This would be the header view in my Recycler
v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.recyclerview_welcome, parent, false);
vh = new ViewHolder(v,viewType);
return vh;
default: //This would be the normal list with the pictures of the places in the world
v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.recyclerview_picture, parent, false);
vh = new ViewHolder(v, viewType);
v.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, nextActivity.class);
intent.putExtra("ListNo",mRecyclerView.getChildPosition(v));
mContext.startActivity(intent);
}
});
return vh;
}
}
//Overridden so that I can display custom rows in the recyclerview
@Override
public int getItemViewType(int position) {
int viewType = 1; //Default is 1
if (position == 0) viewType = 0; //If zero, it will be a header view
return viewType;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
//position == 0 means it's the info header view on the Recycler
if (position == 0) {
holder.name.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext,"name clicked", Toast.LENGTH_SHORT).show();
}
});
holder.description.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext,"description clicked", Toast.LENGTH_SHORT).show();
}
});
//This means it is beyond the headerview now as it is no longer 0. For testing purposes, I'm alternating between two pics for now
} else if (position > 0) {
holder.place.setText(mDataset[position]);
if (position % 2 == 0) {
holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic1));
}
if (position % 2 == 1) {
holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic2));
}
}
}
这是非常简单直接的。
只需在适配器中重写getItemViewType()方法。根据数据返回不同的itemViewType值。例如，考虑一个Person类型的对象，其成员为male，如果isMale为真，则返回1,isMale为假，则在getItemViewType()方法中返回2。
现在来到createViewHolder (ViewGroup parent, int viewType)，在不同的viewType的基础上，你可以膨胀不同的布局文件。像下面这样:
if (viewType == 1){
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.male, parent, false);
return new AdapterMaleViewHolder(view);
}
else{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.female, parent, false);
return new AdapterFemaleViewHolder(view);
}
在onBindViewHolder (VH holder,int position)检查holder是AdapterFemaleViewHolder或AdapterMaleViewHolder的实例，并相应地分配值。
ViewHolder可能是这样的
class AdapterMaleViewHolder extends RecyclerView.ViewHolder {
...
public AdapterMaleViewHolder(View itemView){
...
}
}
class AdapterFemaleViewHolder extends RecyclerView.ViewHolder {
...
public AdapterFemaleViewHolder(View itemView){
...
}
}
下面的代码不是伪代码。我已经测试过了，它对我很有效。
我想在我的recyclerview中创建一个headerview，然后在用户可以点击的标题下面显示一个图片列表。
我在我的代码中使用了一些开关，不知道这是否是最有效的方法，所以请随意给出您的评论:
public class ViewHolder extends RecyclerView.ViewHolder{
//These are the general elements in the RecyclerView
public TextView place;
public ImageView pics;
//This is the Header on the Recycler (viewType = 0)
public TextView name, description;
//This constructor would switch what to findViewBy according to the type of viewType
public ViewHolder(View v, int viewType) {
super(v);
if (viewType == 0) {
name = (TextView) v.findViewById(R.id.name);
decsription = (TextView) v.findViewById(R.id.description);
} else if (viewType == 1) {
place = (TextView) v.findViewById(R.id.place);
pics = (ImageView) v.findViewById(R.id.pics);
}
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType)
{
View v;
ViewHolder vh;
// create a new view
switch (viewType) {
case 0: //This would be the header view in my Recycler
v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.recyclerview_welcome, parent, false);
vh = new ViewHolder(v,viewType);
return vh;
default: //This would be the normal list with the pictures of the places in the world
v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.recyclerview_picture, parent, false);
vh = new ViewHolder(v, viewType);
v.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, nextActivity.class);
intent.putExtra("ListNo",mRecyclerView.getChildPosition(v));
mContext.startActivity(intent);
}
});
return vh;
}
}
//Overridden so that I can display custom rows in the recyclerview
@Override
public int getItemViewType(int position) {
int viewType = 1; //Default is 1
if (position == 0) viewType = 0; //If zero, it will be a header view
return viewType;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
//position == 0 means it's the info header view on the Recycler
if (position == 0) {
holder.name.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext,"name clicked", Toast.LENGTH_SHORT).show();
}
});
holder.description.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext,"description clicked", Toast.LENGTH_SHORT).show();
}
});
//This means it is beyond the headerview now as it is no longer 0. For testing purposes, I'm alternating between two pics for now
} else if (position > 0) {
holder.place.setText(mDataset[position]);
if (position % 2 == 0) {
holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic1));
}
if (position % 2 == 1) {
holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic2));
}
}
}
你可以使用这个图书馆:https://github.com/vivchar/RendererRecyclerViewAdapter
mRecyclerViewAdapter = new RendererRecyclerViewAdapter(); /* Included from library */
mRecyclerViewAdapter.registerRenderer(new SomeViewRenderer(SomeModel.TYPE, this));
mRecyclerViewAdapter.registerRenderer(...); /* You can use several types of cells */
对于每一个项目，你应该实现一个ViewRenderer, ViewHolder, SomeModel:
ViewHolder -它是回收器视图的一个简单视图持有者。
SomeModel -它是你的模型与ItemModel接口
public class SomeViewRenderer extends ViewRenderer<SomeModel, SomeViewHolder> {
public SomeViewRenderer(final int type, final Context context) {
super(type, context);
}
@Override
public void bindView(@NonNull final SomeModel model, @NonNull final SomeViewHolder holder) {
holder.mTitle.setText(model.getTitle());
}
@NonNull
@Override
public SomeViewHolder createViewHolder(@Nullable final ViewGroup parent) {
return new SomeViewHolder(LayoutInflater.from(getContext()).inflate(R.layout.some_item, parent, false));
}
}
有关更多详细信息，您可以查看文档。
