如果tag的名字不是TAG_1995(名字是个梗),就调用函数createViewFromTag()创建View,进去看看,
View createViewFromTag(View parent, String name, AttributeSet attrs) {
if (name.equals("view")) {
name = attrs.getAttributeValue(null, "class");
}
......
View view;
if (mFactory2 != null) view = mFactory2.onCreateView(parent, name, mContext, attrs);
else if (mFactory != null) view = mFactory.onCreateView(name, mContext, attrs);
else view = null;
if (view == null && mPrivateFactory != null) {
view = mPrivateFactory.onCreateView(parent, name, mContext, attrs);
}
if (view == null) {
if (-1 == name.indexOf('.')) {
view = onCreateView(parent, name, attrs);
} else {
view = createView(name, null, attrs);
}
}
if (DEBUG) System.out.println("Created view is: " + view);
return view;
......
}
首先尝试用3个Fractory创建View,如果成功就直接返回了。注意,我们可以利用这个机制,创建自己的Factory来控制View的创建过程。
如果没有Factory或创建失败,那么走默认逻辑。
先判断name中是否有'.'字符,如果没有,则认为使用android自己的View,此时会在name的前面加上包名"android.view.";如果有这个'.',则认为使用的自定义View,这时无需添加任何前缀,认为name已经包含全包名了。
最终,使用这个全包名的name来创建实例,
private static final HashMap<String, Constructor<? extends View>> sConstructorMap =
new HashMap<String, Constructor<? extends View>>();
protected View onCreateView(String name, AttributeSet attrs)
throws ClassNotFoundException {
return createView(name, "android.view.", attrs);
}
public final View createView(String name, String prefix, AttributeSet attrs)
throws ClassNotFoundException, InflateException {
Constructor<? extends View> constructor = sConstructorMap.get(name);
Class<? extends View> clazz = null;
......
if (constructor == null) {
// Class not found in the cache, see if it's real, and try to add it
clazz = mContext.getClassLoader().loadClass(
prefix != null ? (prefix + name) : name).asSubclass(View.class);
if (mFilter != null && clazz != null) {
boolean allowed = mFilter.onLoadClass(clazz);
if (!allowed) {
failNotAllowed(name, prefix, attrs);
}
}
constructor = clazz.getConstructor(mConstructorSignature);
sConstructorMap.put(name, constructor);
} else {
// If we have a filter, apply it to cached constructor
if (mFilter != null) {
// Have we seen this name before?
Boolean allowedState = mFilterMap.get(name);
if (allowedState == null) {
// New class -- remember whether it is allowed
clazz = mContext.getClassLoader().loadClass(
prefix != null ? (prefix + name) : name).asSubclass(View.class);
boolean allowed = clazz != null && mFilter.onLoadClass(clazz);
mFilterMap.put(name, allowed);
if (!allowed) {
failNotAllowed(name, prefix, attrs);
}
} else if (allowedState.equals(Boolean.FALSE)) {
failNotAllowed(name, prefix, attrs);
}
}
}
Object[] args = mConstructorArgs;
args[1] = attrs;
return constructor.newInstance(args);
......
}










