在inflate时取到组件和获取属性的方法

• 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);
    }
}