[移动开发]Android BaseAdapter 简化版

在安卓应用开发时，适配器的使用非常频繁，而适配器的代码又有许多是重复的，因此对BaseAdapter进行一个封装，去除其中重复又繁琐的部分，其它的适配器也同样如此

BaseAdapter封装

package com.example.myapplication;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

import java.lang.reflect.InvocationTargetException;
import java.util.List;

public abstract class MyBaseAdapter <T, H> extends BaseAdapter {
    protected final List<T> dataList;

    public MyBaseAdapter(List<T> dataList) {
        this.dataList = dataList;
    }
    protected abstract Class<H> getHolderClass();
    protected abstract CallBack<T, H> getCallBack();
    protected abstract int getLayout();

    @Override
    public int getCount() {
        return dataList.size();
    }

    @Override
    public T getItem(int i) {
        return dataList.get(i);
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        Context context = viewGroup.getContext();
        H holder = null;
        if (view == null) {
            view = LayoutInflater.from(context).inflate(getLayout(), null, false);
            try {
                holder = getHolderClass().getDeclaredConstructor(View.class).newInstance(view);
            } catch (IllegalAccessException | InstantiationException | InvocationTargetException | NoSuchMethodException e) {
                e.printStackTrace();
            }
            view.setTag(holder);
        } else
            holder = (H) view.getTag();
        getCallBack().operate(getItem(i), i, holder, context);
        return view;
    }

    public void addData(List<T> list) {
        dataList.addAll(list);
    }
    public void addData(T t) {
        dataList.add(t);
    }

    public List<T> getDataList() {
        return dataList;
    }

    public T getData(int pos) {
        return dataList.get(pos);
    }
    public void clearData() {
        dataList.clear();
    }

    public interface CallBack <T, H> {
        void operate(T item, int pos, H holder, Context context);
    }
}

MyBaseAdapter的使用

package com.example.myapplication;

import android.content.Context;
import android.view.View;
import android.widget.TextView;

import java.util.List;

public class TestAdapter extends MyBaseAdapter<TestBean, TestAdapter.ViewHolder> {
    public TestAdapter(List<TestBean> dataList) {
        super(dataList);
    }

    @Override
    Class<ViewHolder> getHolderClass() {
        return ViewHolder.class;
    }

    @Override
    CallBack<TestBean, ViewHolder> getCallBack() {
        return new CallBack<TestBean, ViewHolder>() {
            @Override
            public void operate(TestBean item, int pos, ViewHolder holder, Context context) {
                holder.tvTest.setText(item.getId() + "");
            }
        };
    }

    @Override
    protected int getLayout() {
        return R.layout.adapter_test;
    }

    public static
    class ViewHolder {
        public View rootView;
        public TextView tvTest;

        public ViewHolder(View rootView) {
            this.rootView = rootView;
            this.tvTest = (TextView) rootView.findViewById(R.id.tvTest);
        }

    }
}

class TestBean {
    private int id;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }
}

不使用封装的BaseAdapter

package com.example.myapplication;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

public class T2Adapter extends BaseAdapter {
    public List<TestBean> dataList;

    public T2Adapter(List<TestBean> dataList) {
        this.dataList = dataList;
    }

    @Override
    public int getCount() {
        return dataList.size();
    }

    @Override
    public TestBean getItem(int i) {
        return dataList.get(i);
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        Context context = viewGroup.getContext();
        ViewHolder holder = null;
        if (view == null) {
            view = LayoutInflater.from(context).inflate(R.layout.adapter_test, null, false);
            holder = new ViewHolder(view);
            view.setTag(holder);
        } else
            holder = (ViewHolder) view.getTag();
        TestBean item = getItem(i);
        holder.tvTest.setText(item.getId() + "");
        return view;
    }

    public static
    class ViewHolder {
        public View rootView;
        public TextView tvTest;

        public ViewHolder(View rootView) {
            this.rootView = rootView;
            this.tvTest = (TextView) rootView.findViewById(R.id.tvTest);
        }

    }
}