Android中通过Tag为View保存数据绑定数据

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项目中有时候需要为View绑定数据，比如每一个云标签都对应服务器一个标签id，View中setTag可以方便的为控件绑定数据。

为控件绑定数据：

selectCategory.setTag(R.id.tag_id, id);selectCategory.setTag(R.id.tag_type, type);

读取控件绑定的数据：

Object object=selectCategory.getTag(R.id.tag_id);if(object!=null&& object instanceof Integer){    ...

setTag的源码：

/** * Sets a tag associated with this view and a key. A tag can be used * to mark a view in its hierarchy and does not have to be unique within * the hierarchy. Tags can also be used to store data within a view * without resorting to another data structure. * * The specified key should be an id declared in the resources of the * application to ensure it is unique (see the <a * href={@docRoot}guide/topics/resources/more-resources.html#Id">ID resource type</a>). * Keys identified as belonging to * the Android framework or not associated with any package will cause * an {@link IllegalArgumentException} to be thrown. * * @param key The key identifying the tag * @param tag An Object to tag the view with * * @throws IllegalArgumentException If they specified key is not valid * * @see #setTag(Object) * @see #getTag(int) */public void setTag(int key, final Object tag) {    // If the package id is 0x00 or 0x01, it's either an undefined package    // or a framework id    if ((key >>> 24) < 2) {        throw new IllegalArgumentException("The key must be an application-specific "                + "resource id.");    }    setKeyedTag(key, tag);}

可以为View绑定key-value数据，但是key不能随便取值，必须取资源文件中资源id，保证id的唯一

如可在string.xml中设置两个常量

<item name="tag_id" type="id"></item><item name="tag_type" type="id"></item>

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