android - fragment 中没有自定义 View 的自定义 XML 属性

Question

我正在尝试在现有 View 中添加自定义 XML 属性

将它们添加到自定义 View 不是什么大问题，但我不知道如何在“基本” View (例如 TextView、LinearLayout、ImageView ...)中访问这些属性

当涉及 Fragment 和/或 Library 项目时，这会更加困难

到目前为止，这是我的代码

海关属性定义和 XML(attrs.xml 和布局):

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="StarWars">
    <attr name="jedi" format="string" />
    <attr name="rank" format="string" />
</declare-styleable>

<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:sw="http://schemas.android.com/apk/res-auto"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

<TextView
    android:id="@+id/name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="28dp"
    android:gravity="center_horizontal"
    sw:jedi="Obiwan" />

<TextView
    android:id="@+id/rank"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="28dp"
    android:gravity="center_horizontal"
    sw:rank="Master" />

因为我在 Fragment 上膨胀了它(所以没有 onCreate with attrs arg!)，尝试获取 2 sw 自定义属性的唯一方法是:

1. 在onCreateView中为Fragment LayoutInflater设置自定义LayoutInflater.Factory

   @Override
   public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
     super.onCreateView(inflater, container, savedInstanceState);
   
     LayoutInflater layoutInflater = inflater.cloneInContext(inflater.getContext());
     layoutInflater.setFactory(new StarWarsLayoutFactory());
   
     View fragmentView = layoutInflater.inflate(R.layout.jedi, container, false);
     ((TextView) fragmentView.findViewById(android.R.id.jedi)).setText("Yep");
   
     return fragmentView;
   }
   

2. 尝试获取自定义 LayoutInflater.Factory 的自定义属性:

   public class StarWarsLayoutFactory implements Factory {
     @Override
     public View onCreateView(String name, Context context, AttributeSet attrs) {
                 *** What to do here ? ***
   
         return null;
     }
   }
   

有人遇到过这样的问题吗？

我在这里缺少什么？

提前致谢!

Answer 1

我终于做到了:)

您必须像我在 OP 中所做的那样创建一个新的 LayoutInflater.Factory 但由于工厂用于所有膨胀的布局 View ，并且您必须在您的 Factory 上返回 null .onCreateView(让 Android 处理通货膨胀)你必须在某处缓存你的自定义 XML 属性

这里是解决方案:

• 您的布局 XML View 必须具有 android:id

• 创建将保留您的自定义属性的类:

    public class AttributeParser {

    private AttributeParserFactory mFactory;
    private Map<Integer, HashMap<Integer, String>> mAttributeList;

    private class AttributeParserFactory implements LayoutInflater.Factory{
        @Override
        public View onCreateView(String name, Context context, AttributeSet attrs) {
            String id = attrs.getAttributeValue("http://schemas.android.com/apk/res/android", "id");

            if(id != null){
                // String with the reference character "@", so we strip it to keep only the reference
                id = id.replace("@", "");

                TypedArray libraryStyledAttributeList = context.obtainStyledAttributes(attrs, R.styleable.NewsHubLibrary);
                HashMap<Integer, String> libraryViewAttribute = new HashMap<Integer, String>();
                int i = 0;

                for(int attribute : R.styleable.NewsHubLibrary){
                    String attributeValue = libraryStyledAttributeList.getString(i);

                    if(attributeValue != null)
                        libraryViewAttribute.put(attribute, attributeValue);

                    i++;
                }

                if(!libraryViewAttribute.isEmpty())
                    mAttributeList.put(Integer.valueOf(id), libraryViewAttribute);

                libraryStyledAttributeList.recycle();
            }

            return null;
        }

    }

    public AttributeParser(){
        mAttributeList = new HashMap<Integer, HashMap<Integer, String>>();
        mFactory = new AttributeParserFactory();
    }

    public void clear() {
        mAttributeList.clear();
    }

    public LayoutInflater getLayoutInflater(LayoutInflater inflater) {
        clear();
        LayoutInflater layoutInflater = inflater.cloneInContext(inflater.getContext());
        layoutInflater.setFactory(mFactory);

        return layoutInflater;
    }

    public void setFactory(LayoutInflater inflater){
        inflater.cloneInContext(inflater.getContext()).setFactory(mFactory);
    }

    public void setViewAttribute(Activity activity) {
        for(Entry<Integer, HashMap<Integer, String>> attribute : mAttributeList.entrySet())
            if(activity.findViewById((Integer) attribute.getKey()) != null)
                activity.findViewById((Integer) attribute.getKey()).setTag(attribute.getValue());

    }

    public void setViewAttribute(View view) {
        for(Entry<Integer, HashMap<Integer, String>> attribute : mAttributeList.entrySet())
            if(view.findViewById((Integer) attribute.getKey()) != null)
                view.findViewById((Integer) attribute.getKey()).setTag(attribute.getValue());
    }

    public Map<Integer, HashMap<Integer, String>> getAttributeList() {
        return mAttributeList;
    }

    public void setAttributeList(Map<Integer, HashMap<Integer, String>> attributeList) {
        this.mAttributeList = attributeList;
    }
    }

• 当您使用 AttributeParser 时，您的自定义属性将存储在每个 View 标签中:

    LayoutInflater layoutInflater = mAttributeParser.getLayoutInflater(inflater);
    View view = layoutInflater.inflate(R.layout.jedi, null);
    mAttributeParser.setViewAttribute(view);