TextView可见性更改通知 [英] TextView visibility change notification

问题描述

我需要检测何时使可见以及何时使其不可见.有什么办法可以在Android中做到这一点吗?当我的应用程序中的TextView更改可见性时，我必须进行一些处理.实际上，它的可见性正在许多地方更新，我希望避免在所有这些地方打来电话.

I need to detect when a TextView is made visible and when its made invisible. Is there any way to do this in Android? I've to make some processing when a TextView in my application changes visibility. Actually, it's visibility is being updated at a number of places and I'm looking to avoid calls at all of these places.

推荐答案

我不知道这是否可以回答您的问题，但是如果您想收听textview的可见性更改，建议您自定义TextView并实现自己的侦听器它.

I don't know if this will answer your question, but if you want to listen to textview visibility changes, I suggest customizing TextView and implement your own listener for it.

 public class TextViewExtension extends TextView {


     protected OnVisibilityChange mChangeListener = null;

     public interface OnVisibilityChange {
         void onChange(TextViewExtension mTextView, int mPrevVisibility, int mNewVisibility);
     }

     public TextViewExtension(Context context) {
         super(context);
         // TODO Auto-generated constructor stub
     }

     /* (non-Javadoc)
      * @see android.view.View#setVisibility(int)
      */
     @Override
     public void setVisibility(int visibility) {
         // TODO Auto-generated method stub
         super.setVisibility(visibility);
         if (mChangeListener != null) {
             mChangeListener.onChange(this, getVisibility(), visibility);
         }
     }

     public void setOnVisibilityChange(OnVisibilityChange mChangeListener) {
         this.mChangeListener = mChangeListener;
     }
 }

如果您好奇的话，这里有一些进一步实施的示例

希望它会有所帮助:)

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