Android RecyclerView優雅實現複雜列表佈局(一)
阿新 • • 發佈:2019-02-16
前言
在多彩佈局不斷呈現的今天,多佈局混合排布成為一個時尚,今天就結合Holder實現RecyclerView複雜列表佈局。
效果圖如下(三種佈局):
1.首先在我們主佈局中加入我們的RecyclerView控制元件。
2.在MainActivity中初始化我們的控制元件
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview);
3.然後對RecyclerView設定佈局資訊和介面卡
mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)); mAdapter = new DemoAdapter(this); mRecyclerView.setAdapter(mAdapter);
4.建立RecyclerView使用的介面卡,完整的Adapter程式碼如下:
/** * @author :huangxianfeng on 2017/3/14. * RecyclerView的介面卡 */ public class DemoAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> { private LayoutInflater mLayoutInflater; /** * 把addList()獲得的資料新增過來 */ private ArrayList<DataModel> mList = new ArrayList<>(); public DemoAdapter(Context context) { mLayoutInflater = LayoutInflater.from(context); } /** * 建立一個方法供外面操作此資料 * @param list */ public void addList(ArrayList<DataModel> list){ mList.addAll(list); } @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { switch (viewType){ case DataModel.TYPE_ONE: return new TypeOneViewHolder(mLayoutInflater.inflate(R.layout.item_type_one,parent,false)); case DataModel.TYPE_TWO: return new TypeTwoViewHolder(mLayoutInflater.inflate(R.layout.item_type_two,parent,false)); case DataModel.TYPE_THREE: return new TypeThreeViewHolder(mLayoutInflater.inflate(R.layout.item_type_three,parent,false)); } return null; } @Override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { ((TypeAbstractViewHolder)holder).bindHolder(mList.get(position)); } /** * 多種佈局時候至關重要的方法 * @param position * @return */ @Override public int getItemViewType(int position) { //得到不同的佈局型別 return mList.get(position).type; } @Override public int getItemCount() { return mList.size(); } }
其中有一個方法不能不提,起到了多佈局實現的關鍵方法,getItemViewType()獲取不同的型別,在我們快取中;
建立一個數據繫結實體,供在傳遞資料:
/** * @author :huangxianfeng on 2017/3/14. * 資料封裝類 */ public class DataModel { public static final int TYPE_ONE = 1; public static final int TYPE_TWO = 2; public static final int TYPE_THREE = 3; public int type; public int avatarColor; public String name; public String content; public int contentColor; }
5.如第4中,有這樣幾行程式碼:
switch (viewType){
case DataModel.TYPE_ONE:
return new TypeOneViewHolder(mLayoutInflater.inflate(R.layout.item_type_one,parent,false));
case DataModel.TYPE_TWO:
return new TypeTwoViewHolder(mLayoutInflater.inflate(R.layout.item_type_two,parent,false));
case DataModel.TYPE_THREE:
return new TypeThreeViewHolder(mLayoutInflater.inflate(R.layout.item_type_three,parent,false));
}
這是通過三個不同的ViewHolder實現不同的三個佈局。其實此處是抽象出一個抽象的TypeAbstractViewHolder,而TypeOneViewHolder,TypeTwoViewHolder,TypeThreeViewHolder分別繼承於TypeAbstractViewHolder,並實現bindHolder()方法
/**
* @author :huangxianfeng on 2017/3/14.
* ViewHolder基類
* 每一種佈局都封裝成一個ViewHolder,繼承此類實現BindHolder方法
*/
public abstract class TypeAbstractViewHolder extends RecyclerView.ViewHolder{
public TypeAbstractViewHolder(View itemView) {
super(itemView);
}
public abstract void bindHolder(DataModel model);
}
此處以TypeOneViewHolder為例:
/**
* @author :huangxianfeng on 2017/3/14.
*/
public class TypeOneViewHolder extends TypeAbstractViewHolder {
public ImageView avatar;
public TextView name;
public TypeOneViewHolder(View itemView) {
super(itemView);
avatar = (ImageView)itemView.findViewById(R.id.avatar);
name = (TextView)itemView.findViewById(R.id.name);
}
@Override
public void bindHolder(DataModel model){
avatar.setBackgroundResource(model.avatarColor);
name.setText(model.name);
}
}
6.MainActivity方法中,其實就是初始化各種資料:
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private DemoAdapter mAdapter;
/**
* 隨機一下顏色
*/
int colors[] ={android.R.color.holo_red_dark,
android.R.color.holo_blue_dark,
android.R.color.holo_orange_dark};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initUI();
}
private void initUI() {
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
mAdapter = new DemoAdapter(this);
mRecyclerView.setAdapter(mAdapter);
initData();
}
private void initData() {
ArrayList<DataModel> mArrayList = new ArrayList<>();
for (int i = 0; i < 20; i++) {
int type = (int) ((Math.random() * 3)+1);
DataModel data = new DataModel();
data.avatarColor = colors[type-1];
data.type = type;
data.name = "name : "+ i;
data.content = "content : "+ i;
data.contentColor = colors[(type+1)%3];
mArrayList.add(data);
}
/**
* 把資料新增到Adapter中去
*/
mAdapter.addList(mArrayList);
mAdapter.notifyDataSetChanged();
}
}