为什么要造轮子
自己平常写代码一直用ButterKnife，功能太强大了有木有！但是最近有个需要在匿名内部类中去findView的时候却发现ButterKnife好像不支持在匿名内部类中进行find，（我也不确定支不支持，反正没找到相应的方法）编译后没有生成相应的ViewBinder类，应该是编译时故意忽略了匿名内部类吧。所以此时也很无奈啊。。。只能自己动手丰衣足食了。
内容为原创，希望能给需要的人帮助，不喜勿喷
一、思路
将需要查找的View包装成WrapView对象放到查找队列中，指定View的类型和id，在容器（activity，fragment等）初始化完View以后再调用ViewFinder的findFrom方法进行查找。
需要使用View时调用WrapView的get()方法将View取出。
使用起来确实稍微有点麻烦。。。不过作为强迫症患者，这样的代码↓↓↓能把我逼疯
public class MainActivity extends Activity{
private TextView nameTv;
private TextView ageTv;
private TextView sexTv;
private TextView nationTv;
private TextView addressTv;
private Button confirmBtn;
private Button cancelBtn;
private Button closeBtn;
private LinearLayout mainLayout;
private LinearLayout loadingLayout;
private LinearLayout errorLayout;
onCreate(){
supper.onCreate();
setConentView(R.layout.activity_main);
findViews();
initView();
}
public void findViews(){
nameTv = (TextView) findViewById(R.id.tv_name);
ageTv= (TextView) findViewById(R.id.tv_age);
sexTv= (TextView) findViewById(R.id.tv_sex);
nationTv = (TextView) findViewById(R.id.tv_nation);
addressTv= (TextView) findViewById(R.id.tv_address);
confirmBtn = (Button) findViewById(R.id.btn_confirm);
cancelBtn= (Button) findViewById(R.id.btn_cancel);
closeBtn = (Button) findViewById(R.id.btn_close);
mainLayout= (LinearLayout) findViewById(R.id.layout_main);
loadingLayout= (LinearLayout) findViewById(R.id.layout_loading);
errorLayout= (LinearLayout) findViewById(R.id.layout_error);
}
public void initView(){
nameTv.setText("张三");
ageTv.setText("26");
sexTv.setText("男");
...
}
...
}
经过改进后的代码是这样的
public class MainActivity extends Activity{
private ViewFinder finder = new ViewFinder();
private WrapView<TextView> nameTv= finder.apply(R.id.tv_name);
private WrapView<TextView> ageTv= finder.apply(R.id.tv_age);
private WrapView<TextView> sexTv= finder.apply(R.id.tv_sex);
private WrapView<TextView> nationTv= finder.apply(R.id.tv_nation);
private WrapView<TextView> addressTv= finder.apply(R.id.tv_address);
private WrapView<Button> confirmBtn= finder.apply(R.id.btn_confirm);
private WrapView<Button> cancelBtn= finder.apply(R.id.btn_cancel);
private WrapView<Button> closeBtn= finder.apply(R.id.btn_close);
private WrapView<LinearLayout > mainLayout= finder.apply(R.id.layout_main);
private WrapView<LinearLayout > loadingLayout= finder.apply(R.id.layout_loading);
private WrapView<LinearLayout > errorLayout= finder.apply(R.id.layout_error);
onCreate(){
supper.onCreate();
setConentView(R.layout.activity_main);
finder.findFrom(this);
initView();
}
public void initView(){
nameTv.get().setText("张三");
ageTv.get()..setText("26");
sexTv.get()..setText("男");
confirmBtn.get().setOnclickListener(this);
...
}
...
}
二、WrapView 和 ViewFinder的代码
WrapView
/**
* Wapper class to maintain View.
* Created by Leo on 2018/2/12.
*/
public class WrapView<T extends View> {
private T view;
@IdRes
private int id;
WrapView(@IdRes int id) {
this.id = id;
}
public T get() {
return view;
}
void setView(T view) {
this.view = view;
}
void find(View from) {
if (from == null) throw new NullPointerException("find view from a null object.");
view = (T) from.findViewById(id);
if (view == null) throw new ViewNotFoundException("View not found for id : " + id);
}
void find(Activity from) {
if (from == null) throw new NullPointerException("find view from a null object.");
view = (T) from.findViewById(id);
if (view == null) throw new ViewNotFoundException("View not found for id : " + id);
}
}
ViewFinder
/**
* Helper class to maintain finding tasks.
* Created by Leo on 2018/2/12.
*/
public class ViewFinder {
private HashMap<Integer, WrapView<?>> views = new HashMap<>();
public <T extends View> WrapView<T> apply(@IdRes int id){
WrapView<T> wrapper = (WrapView<T>) views.get(id);
if (wrapper == null){
wrapper = new WrapView<>(id);
views.put(id,wrapper);
}
return wrapper;
}
public void findFrom(View from) {
Collection<WrapView<?>> wrapViews = views.values();
for (WrapView<?> wrapView : wrapViews) {
wrapView.find(from);
}
}
public void findFrom(Activity from) {
Collection<WrapView<?>> wrapViews = views.values();
for (WrapView<?> wrapView : wrapViews) {
wrapView.find(from);
}
}
}