手机开发 2016-11-15
我们日常开发中BaseAdapter使用非常的多,大家有没有想过,再进一步封装,将平常使用的对象集合,利用泛型放入集合中,再也不用每次都重写那几个方法了,当然我也提供我的下载地址(https://github.com/androidsihai1/BaseAdapterDemo)
package com.example.administrator.mybaseadapter; import android.content.Context; import android.widget.TextView; public class MyAdapter extends BaseAdapter { public MyAdapter(Context context) { super(context); } @Override public int getItemViewType(int position) { return 0; } @Override public int getItemLayoutId(int getItemViewType) { return R.layout.item_layout; } @Override public void handleItem(int itemViewType, int position, Object item, ViewHolder holder, boolean isRecycle) { TextView leftTv = holder.get(R.id.left_tv, TextView.class); TextView righTv = holder.get(R.id.right_tv, TextView.class); Book book = (Book) item; leftTv.setText(book.id + ""); righTv.setText(book.name); } }
package com.example.administrator.mybaseadapter; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.ListView; import java.util.ArrayList; import java.util.List; public class MainActivity extends AppCompatActivity { List<Book> mList = new ArrayList<Book>(); ListView mLv ; BaseAdapter<Book> mAdapter; int k = 0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mLv = findView(R.id.lv); for(int i = 0 ; i < 50 ; i++) { Book book = new Book(); k++; book.id = k; book.name = "name " + k; mList.add(book); } mAdapter = new MyAdapter(this); mAdapter.setData(mList); mLv.setAdapter(mAdapter); mAdapter.notifyDataSetChanged(); } public <T extends View> T findView(int viewId) { return (T)findViewById(viewId); } }
package com.example.administrator.mybaseadapter; public class Book { public int id; public String name; }
package com.example.administrator.mybaseadapter; import android.content.Context; import android.util.SparseArray; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import java.util.ArrayList; import java.util.List; /** * Created by [email protected] on 2016/11/15. */ public abstract class BaseAdapter<T> extends android.widget.BaseAdapter { protected Context mContext; protected List<T> mData = new ArrayList<T>(); LayoutInflater mInflater; public BaseAdapter(Context context) { this.mContext = context; mInflater = LayoutInflater.from(context); } final public void setData(List<T> list) { this.mData = list; } final public List<T> getData() { return mData; } @Override final public int getCount() { return mData.size(); } @Override public T getItem(int i) { return mData.get(i); } @Override final public long getItemId(int i) { return i; } public abstract int getItemViewType(int position); public abstract int getItemLayoutId(int getItemViewType); public abstract void handleItem(int itemViewType , int position , T item , ViewHolder holder , boolean isRecycle); @Override public View getView(int position, View view, ViewGroup viewGroup) { int itemLayoutType = getItemViewType(position); ViewHolder viewHolder = null; boolean isRecycle =false; if(view == null) { view = mInflater.inflate(getItemLayoutId(itemLayoutType) , null); viewHolder = new ViewHolder(view); view.setTag(viewHolder); } else { viewHolder = (ViewHolder) view.getTag(); isRecycle = true; } handleItem(itemLayoutType , position ,mData.get(position) , viewHolder , isRecycle); return view; } public static class ViewHolder{ View mRootView; SparseArray<View> mViews = new SparseArray<View>(); public ViewHolder(View view) { this.mRootView = view; } public View getView() { return mRootView; } public <T extends View> T get(int viewId) { View childView = mViews.get(viewId); if(childView == null) { childView = mRootView.findViewById(viewId); mViews.put(viewId , childView); } return (T)childView; } public <T extends View> T get(int viewId , Class<T> viewClass) { View childView = mViews.get(viewId); if(childView == null) { childView = mRootView.findViewById(viewId); mViews.put(viewId , childView); } return (T) childView; } } }
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.administrator.mybaseadapter.MainActivity"> <ListView android:id="@+id/lv" android:layout_width="match_parent" android:layout_height="match_parent" /> </RelativeLayout>
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:text="TextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/left_tv" android:layout_weight="1" /> <TextView android:text="TextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/right_tv" android:layout_weight="1" /> </LinearLayout>