- Android里布局解析器的使用是采用工厂模式实现的,而 LayoutInflater.Factory2 正是那个工厂,我们所需做的就是继承并实现自定义的工厂实现特定功能,如下面的工厂类
- 我的工厂功能是:在create方法中通过判断组件类型是不是textview,并获取TextView的text属性的id值。
- 我的工厂用途是:配合多语言下发框架实现语言在线更新功能。
自定义工厂
public class CustomLanguageFactory implements LayoutInflater.Factory2 {
private static CustomLanguageFactory instance;
private static final String[] mPrefixes = {"android.widget.", "android.webkit.", "android.view."};
private static final String mSchemas = "http://schemas.android.com/apk/res/android";
private static final String mAttrText = "text";
private CustomLanguageFactory() {
}
public static CustomLanguageFactory getInstance() {
return instance != null ? instance : (instance = new CustomLanguageFactory());
}
public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
return createView(name, context, attrs);
}
public View onCreateView(String name, Context context, AttributeSet attrs) {
return createView(name, context, attrs);
}
private View createView(String name, Context context, AttributeSet attrs) {
View v = !name.contains(".") ? null : create(name, null, context, attrs);
if (v == null) {
for (String prefix : mPrefixes) {
v = create(name, prefix, context, attrs);
if (v != null) {
break;
}
}
}
return v;
}
private static View create(String name, String prefix, Context context, AttributeSet attrs) {
try {
View v = LayoutInflater.from(context).createView(name, prefix, attrs);
if (v instanceof TextView) {
String res = attrs.getAttributeValue(mSchemas, mAttrText);
res = res.replace("@", "");
if (res != null && res.length() > 0) {
int textId = Integer.parseInt(res);
((TextView) v).setText(context.getText(textId));
}
}
return v;
} catch (Throwable e) {
return null;
}
}
public static void attach(Activity a) {
attach(a.getLayoutInflater());
}
public static void attach(Dialog d) {
attach(d.getLayoutInflater());
}
public static void attach(LayoutInflater li) {
if (!(li.getFactory2() instanceof CustomLanguageFactory) && !(li.getFactory() instanceof CustomLanguageFactory)) {
li.setFactory2(getInstance());
}
}
}
使用工厂
- 通过实现BaseActivity,并让有需要的Activity继承
public class BaseActivity extends AppCompatActivity{
@Override
public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
View v = super.onCreateView(parent, name, context, attrs);
if (v == null) {
CustomLanguageFactory.getInstance().onCreateView(parent, name, context, attrs);
}
return v;
}
@Override
public View onCreateView(String name, Context context, AttributeSet attrs) {
View v = super.onCreateView(name, context, attrs);
if (v == null) {
CustomLanguageFactory.getInstance().onCreateView(name, context, attrs);
}
return v;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
getLayoutInflater().setFactory2(CustomLanguageFactory.getInstance());
super.onCreate(savedInstanceState);
}
}