Android的EDITTEXT：在活动的onCreate获取LineCount（） [英] Android Edittext: Get LineCount in an Activity's onCreate()

问题描述

我怎样才能做一个EDITTEXT的getLineCount（）在活动的onCreate（）方法，已经改变了EDITTEXT的文字，如下所示：

How can I do getLineCount() of an Edittext in the onCreate() method of an activity, having changed the Edittext's text, like the following:

    @override
    public void onCreate(Bundle savedInstanceState){
        myEditText.setText("EXAMPLE");
        myEditText.getLineCount();
    }

由于该视图尚未拟定尚未getLineCount（）始终返回0是有办法来解决这个问题呢？谢谢！

Because the view has not been drawn yet getLineCount() will always return 0. Is there a way to get around this problem? Thanks!

推荐答案

这绝对是一种痛苦。在我来说，我并不需要编辑，所以我用的TextView 但看到的EditText 派生自<$ C工作$ C>的TextView ，你应该能够使用同样的方法。我子类的TextView 和实施 onSizeChanged 来调用一个新的监听我称之为 OnSizeChangedListener 。在听众可以拨打 getLineCount（）与有效的结果。

This is definitely a pain. In my case I didn't need editing, so I worked with TextView but seeing as EditText derives from TextView you should be able to use the same approach. I subclassed TextView and implemented onSizeChanged to call a new listener which I called OnSizeChangedListener. In the listener you can call getLineCount() with valid results.

的的TextView ：

/** Size change listening TextView. */
public class SizeChangeNotifyingTextView extends TextView {
    /** Listener. */
    private OnSizeChangeListener m_listener;

    /**
     * Creates a new Layout-notifying TextView.
     * @param context   Context.
     * @param attrs     Attributes.
     */
    public SizeChangeNotifyingTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * Adds a size change listener.
     * @param listener  Listener.
     */
    public void setOnSizeChangedListener(OnSizeChangeListener listener) {
        m_listener = listener;
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        if (m_listener != null) {
            m_listener.onSizeChanged(w, h, oldw, oldh);
        }
    }
}

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