Android的Adapter

<span style="font-family:Microsoft YaHei;font-size:12px;">在實際開發的時候,Adapter用的比較多,通常複雜點的項目都會用到BaseAdapter,當然有很多大牛都寫了通用的Adapter.</span>

在GitHub上有BaseAdapter的實現:

https://github.com/JoanZapata/base-adapter-helper ;

這是CSDN博客上的實現:

http://blog.csdn.net/lmj623565791/article/details/38902805;

http://blog.csdn.net/bboyfeiyu/article/details/38947721;

以及http://stormzhang.github.io/androidtips/2014/08/31/android-common-simplebaseadapter/;

最後一個是最簡單的,而且我覺得是最好的,因爲需求總是不斷變化的,我們需要改的地方還有很多,所以不需要面

面俱到用的時候在修改即可.

貼出最後一個實現的代碼:

<span style="font-family:Microsoft YaHei;font-size:12px;">import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.util.SparseArray;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
public abstract class SimpleBaseAdapter<T> extends BaseAdapter {
	protected Context context;
	protected List<T> data;
	public SimpleBaseAdapter(Context context, List<T> data) {
		this.context = context;
		this.data = (data == null ? new ArrayList<T>(0)
				: new ArrayList<T>(data));
	}
	@Override
	public int getCount() {
		return data.size();
	}
	@Override
	public Object getItem(int position) {
		if (position > data.size()) {
			return null;
		}
		return data.get(position);
	}
	@Override
	public long getItemId(int position) {
		return position;
	}
	/**
	 * 該方法需要子類實現,需要返回item佈局的resource id
	 * 
	 * @return 佈局的resource id
	 */
	public abstract int getItemResource();
	/**
	 * 使用該getItemView方法替換原來的getView方法，需要子類實現 
	 * 查找控件用viewHolder的getView傳入id
	 * 
	 * @param position
	 * @param convertView
	 * @param parent
	 * @param holder
	 * @return
	 */
	public abstract View getItemView(int position, View convertView,
			ViewHolder holder);
	@SuppressWarnings("unchecked")
	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		ViewHolder holder;
		if (null == convertView) {
			convertView = View.inflate(context, getItemResource(), null);
			holder = new ViewHolder(convertView);
			convertView.setTag(holder);
		} else {
			holder = (ViewHolder) convertView.getTag();
		}
		return getItemView(position, convertView, holder);
	}
	/**
	 * ViewHolder可以獲取控件
	 * @author ...
	 *
	 */
	public class ViewHolder {
		private SparseArray<View> views = new SparseArray<View>(0);
		private View convertView;
		public ViewHolder(View convertView) {
			this.convertView = convertView;
		}
		@SuppressWarnings({ "unchecked", "hiding" })
		public <T extends View> T getView(int resId) {
			View v = views.get(resId);
			if (null == v) {
				v = convertView.findViewById(resId);
				views.put(resId, v);
			}
			return (T) v;
		}
	}
	/**
	 * 添加在頭部
	 * 
	 * @param elem
	 */
	public void addFirst(List<T> elem) {
		data.addAll(0, elem);
		notifyDataSetChanged();
	}
	/**
	 * 添加在尾部
	 * 
	 * @param elem
	 */
	public void addLast(List<T> elem) {
		data.addAll(elem);
		notifyDataSetChanged();
	}
	/**
	 * 按位置添加
	 * 
	 * @param position
	 * @param elem
	 */
	public void addByPosition(int position, List<T> elem) {
		data.addAll(position, elem);
		notifyDataSetChanged();
	}
	/**
	 * 根據元素移除數據
	 * 
	 * @param elem
	 */
	public void remove(T elem) {
		data.remove(elem);
		notifyDataSetChanged();
	}
	/**
	 * 根據位置移除數據
	 * 
	 * @param index
	 */
	public void remove(int index) {
		data.remove(index);
		notifyDataSetChanged();
	}
	/**
	 * 替換所有數據
	 * 
	 * @param elem
	 */
	public void replaceAll(List<T> elem) {
		data.clear();
		data.addAll(elem);
		notifyDataSetChanged();
	}
}</span>

使用也很簡單:

<span style="font-family:Microsoft YaHei;font-size:12px;">import java.util.List;
import android.content.Context;
import android.view.View;
import android.widget.TextView;
public class MyAdapter extends SimpleBaseAdapter<String> {
	public MyAdapter(Context context, List<String> data) {
		super(context, data);
	}
	@Override
	public int getItemResource() {
		return android.R.layout.simple_list_item_1;
		// return R.layout.list_cell_item;
	}
	@Override
	public View getItemView(int position, View convertView,
			SimpleBaseAdapter<String>.ViewHolder holder) {
		// TextView t = holder.getView(R.id.tv);
		TextView t = holder.getView(android.R.id.text1);
		t.setText(getItem(position).toString());
		return convertView;
	}
}</span>

這段代碼應該很好懂的.