Adapter简化写法以及findViewById()方法的优化

首先写个ViewHolder:

public class ViewHolder {    private View mConvertView;    private Activity mActivity;    private SparseArray<View> mViewArray;   // 包含了View引用的SparseArray    public ViewHolder(View convertView) {        this.mConvertView = convertView;    }    public ViewHolder(Activity activity) {        this.mActivity = activity;    }    public <T extends View> T get(int viewId) {//通过ViewId得到View        if (mActivity == null) {// ListAdapter的ViewHolder            SparseArray<View> viewHolder = (SparseArray<View>) mConvertView.getTag();            if (viewHolder == null) {                viewHolder = new SparseArray<View>();                mConvertView.setTag(viewHolder);            }            View childView = viewHolder.get(viewId);            if (childView == null) {                childView = mConvertView.findViewById(viewId);                viewHolder.put(viewId, childView);            }            return (T) childView;        } else { // Activity的ViewHolder            if (mViewArray == null) {                mViewArray = new SparseArray<View>();            }            View childView = mViewArray.get(viewId);            if (childView == null) {                childView = mActivity.findViewById(viewId);                mViewArray.put(viewId, childView);            }            return (T) childView;        }    }    public void setText(int viewId, String text) {// 通过ViewId设置Text        ((TextView) get(viewId)).setText(text);    }    public void setText(int viewId, Spanned text) {// 通过ViewId设置Text        ((TextView) get(viewId)).setText(text);    }    public void setTextColor(int viewId, int color) {//通过ViewId设置TextColor        ((TextView) get(viewId)).setTextColor(color);    }    public void setImageResource(int viewId, int resId) {//通过ViewId设置图片        ((ImageView) get(viewId)).setImageResource(resId);    }    public void setImageBitmap(int viewId, Bitmap bm) {// 通过ViewId设置图片        ((ImageView) get(viewId)).setImageBitmap(bm);    }    public void setImageDrawable(int viewId, Drawable drawable) {//通过ViewId设置图片        ((ImageView) get(viewId)).setImageDrawable(drawable);    }    public void setImageUrl(int id, String url) {//通过ViewId设置网络图片//        Rosemary.loadImage(url, (ImageView) get(id));    }    public void setImageUrl(int id, String url, int resId) {// 通过ViewId设置网络图片//        Rosemary.loadImage(url, (ImageView) get(id), resId);    }    public void setVisibility(int viewId, int visibility) {//通过ViewId设置隐藏和显示        get(viewId).setVisibility(visibility);    }    public void setOnClickListener(int viewId, View.OnClickListener l) {//通过ViewId设置点击监听        get(viewId).setOnClickListener(l);    }}

然后写个BaseActivity:

public class BaseActivity extends ActionBarActivity {    protected ViewHolder mHolder;    public <T> T $(int viewID) {        return (T) mHolder.get(viewID);    }    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        BaseApplication.getInstance().addActivity(this);        mHolder = new ViewHolder(this);    }}

封装个简易Adapter:

public abstract class ListAdapter<T>  extends BaseAdapter {    protected Context mContext;    protected LayoutInflater mInflater;    protected List<T> mList;   // 数据集    protected int mLayoutID;    // 布局资源ID    protected ListAdapter() {    }    public ListAdapter(Context ctx, List<T> list, int layoutID) {        mContext = ctx;        mInflater = LayoutInflater.from(ctx);        mList = list;        mLayoutID = layoutID;    }    @Override    public int getCount() {        if (mList != null && mList.size() > 0) return mList.size();        return 0;    }    @Override    public T getItem(int position) {        if (mList != null && mList.size() > 0) return mList.get(position);        return null;    }    @Override    public long getItemId(int position) {        return position;    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        if (convertView == null) convertView = mInflater.inflate(mLayoutID, null);        ViewHolder holder = new ViewHolder(convertView);        onBind(position, getItem(position), holder);        return convertView;    }    /**     * 绑定数据     */    protected abstract void onBind(int position, T item, ViewHolder holder);}

使用效果:

public class BlacklistActivity extends VolleyActivity implements IInit, IResponseHandler {    private ListView mListView;    private BlacklistViewModel mViewModel = new BlacklistViewModel();    private ListAdapter<BlacklistViewModel> mAdapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_blacklist);        init();    }    @Override    public void init() {        ActionBarUtil.setup(this, "我的黑名单");        mListView = $(R.id.lv_blacklist);        fetchData(FIRST);    }    @Override    public void fetchData(int tag) {        toggleProgress(true);        if (tag == FIRST) {            // 请求黑名单列表            GetBlackBuyerListParam param = new GetBlackBuyerListParam(mViewModel.getPageIndex(), Data.PAGE_SIZE_LARGE, Data.getUserID());            UserApi.getBlackBuyerList(this, param, tag);        } else if (tag == SECOND) {            // 移出黑名单            RemoveBlackBuyerParam param = new RemoveBlackBuyerParam(Data.getUserID(), mViewModel.getList().get(mViewModel.getCurrentPosition()).getModel().getBuyerID());            UserApi.removeBlackBuyer(this, param, tag);        }    }    @Override    public void updateUI(Object response, int tag) {        if (response == null) return;        if (tag == FIRST) {            mViewModel.inflate(response);            // 黑名单列表            if (mAdapter == null) {                mAdapter = new ListAdapter<BlacklistViewModel>(this, mViewModel.getList(), R.layout.item_blacklist) {                    @Override                    protected void onBind(final int position, final BlacklistViewModel item, ViewHolder holder) {                        holder.setImageUrl(R.id.iv_avatar, item.getModel().getHeadImageUrl(), R.drawable.defaultportrait);                        holder.setOnClickListener(R.id.iv_avatar, new View.OnClickListener() {                            @Override                            public void onClick(View v) {                                IntentUtil.toPersonInfo(BlacklistActivity.this, item.getModel().getBuyerID());                            }                        });                        holder.setText(R.id.tv_name, item.getModel().getBuyerName());                        holder.setOnClickListener(R.id.btn_remove, new View.OnClickListener() {                            @Override                            public void onClick(View v) {                                mViewModel.setCurrentPosition(position);                                new AlertDialog.Builder(BlacklistActivity.this).setMessage(String.format("确定将“%s”从黑名单中移除吗？", item.getModel().getBuyerName())).setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {                                    @Override                                    public void onClick(DialogInterface dialog, int which) {                                        fetchData(SECOND);                                    }                                }).setNegativeButton(android.R.string.cancel, null).create().show();                            }                        });                    }                };                mListView.setAdapter(mAdapter);                mListView.setEmptyView(findViewById(R.id.iv_no_data));            } else {                mAdapter.notifyDataSetChanged();            }        } else if (tag == SECOND) {            if (((Boolean) response)) {                ToastUtil.show(this, "移除成功！");                mViewModel.getList().remove(mViewModel.getCurrentPosition());                mAdapter.notifyDataSetChanged();            }        }    }}

总结:

以前要写mListView = (ListView)findViewById(R.id.lv_blacklist);

现在只要写mListView = $(R.id.lv_blacklist);就可以

而且adapter简化成几行代码:

                mAdapter = new ListAdapter<BlacklistViewModel>(this, mViewModel.getList(), R.layout.item_blacklist) {                    @Override                    protected void onBind(final int position, final BlacklistViewModel item, ViewHolder holder) {                        holder.setImageUrl(R.id.iv_avatar, item.getModel().getHeadImageUrl(), R.drawable.defaultportrait);                        holder.setOnClickListener(R.id.iv_avatar, new View.OnClickListener() {                            @Override                            public void onClick(View v) {                                IntentUtil.toPersonInfo(BlacklistActivity.this, item.getModel().getBuyerID());                            }                        });                        holder.setText(R.id.tv_name, item.getModel().getBuyerName());                        holder.setOnClickListener(R.id.btn_remove, new View.OnClickListener() {                            @Override                            public void onClick(View v) {                                mViewModel.setCurrentPosition(position);                                new AlertDialog.Builder(BlacklistActivity.this).setMessage(String.format("确定将“%s”从黑名单中移除吗？", item.getModel().getBuyerName())).setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {                                    @Override                                    public void onClick(DialogInterface dialog, int which) {                                        fetchData(SECOND);                                    }                                }).setNegativeButton(android.R.string.cancel, null).create().show();                            }                        });                    }                };                mListView.setAdapter(mAdapter);