TextView判断是否在省略状态（在列表情况下）

来源：互联网发布：注射水银知乎编辑：程序博客网时间：2024/06/11 03:12

试了下网上常见的做法，并不能满足需求，主要一点是，TextView需要在绘制完成后才能获取到一些相关参数，后面发现了一篇博客：
http://blog.csdn.net/gentlemanyc/article/details/49967719

根据博客的教程，能实现了绘制完成后自动返回状态判断，但是还是不能满足需求，发现其中导致的原因是列表的holder机制引起的，上面博客的判断是在绘制完成后返回判断，列表的holder机制导致可能公用同一个TextView导致状态混乱，解决方法就是对每个列表加个字段保存对应的判断状态。如果没有检测过就进行检测：

 holder.contentText.setCheckText(bean.Content + "",bean);    holder.contentText.setOnOverLineChangedListener(new CheckOverSizeTextView.OnOverSizeChangedListener() {                @Override                public void onChanged(boolean isOverSize,Object tag) {                    if(tag!=null){                        NoticeBean bean = (NoticeBean) tag;                        if(bean.IsCheck){                            if (bean.isOverSize) {                                holder.expand.setVisibility(View.VISIBLE);                            } else {                                holder.expand.setVisibility(View.GONE);                            }                        }else {                            if (isOverSize) {                                bean.isOverSize = true;                                holder.expand.setVisibility(View.VISIBLE);                            } else {                                bean.isOverSize = false;                                holder.expand.setVisibility(View.GONE);                            }                            bean.IsCheck = true;                        }                    }                }            });

手受伤了，手痛，写的有点乱，贴一下修改了的那个类的代码：

import java.lang.reflect.Field;import android.content.Context;import android.graphics.Canvas;import android.text.Layout;import android.text.TextUtils.TruncateAt;import android.util.AttributeSet;import android.view.ViewTreeObserver.OnGlobalLayoutListener;import android.widget.TextView;public class CheckOverSizeTextView extends TextView {    protected boolean isOverSize;    protected Object Tag = null;    private OnOverSizeChangedListener changedListener;    public CheckOverSizeTextView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init();    }    public CheckOverSizeTextView(Context context, AttributeSet attrs) {        super(context, attrs);        init();    }    public CheckOverSizeTextView(Context context) {        super(context);        init();    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (changedListener != null) {            changedListener.onChanged(checkOverLine(),Tag);        }    }    public void setCheckText(CharSequence text, Object tag) {        this.Tag = tag;        super.setText(text);    }    private void init() {        // invalidate when layout end        getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {            @Override            public void onGlobalLayout() {                if (changedListener != null) {                    changedListener.onChanged(checkOverLine(),Tag);                }            }        });    }    /**     * <p>     * <span style="color: purple;">     * <em>check if the text content has ellipsis </em></span>     * </p>     *     * @return if the text content over maxlines     */    public boolean checkOverLine() {        int maxLine = 3;        try {            Field field = getClass().getSuperclass().getDeclaredField("mLayout");            field.setAccessible(true);            Layout mLayout = (Layout) field.get(this);            if (mLayout == null)                return false;            isOverSize = mLayout.getEllipsisCount(maxLine - 1) > 0 ? true : false;        } catch (NoSuchFieldException e) {            e.printStackTrace();        } catch (IllegalAccessException e) {            e.printStackTrace();        } catch (IllegalArgumentException e) {            e.printStackTrace();        }        return isOverSize;    }    public boolean isOverSize() {        return isOverSize;    }    public void displayAll() {        setMaxLines(Integer.MAX_VALUE);        setEllipsize(null);    }    public void hide(int maxlines) {        setEllipsize(TruncateAt.END);        setMaxLines(maxlines);    }    // set a listener for callback    public OnOverSizeChangedListener getChangedListener() {        return changedListener;    }    public void setOnOverLineChangedListener(OnOverSizeChangedListener changedListener) {        this.changedListener = changedListener;    }    public interface OnOverSizeChangedListener {        /**         * <span style="color:purple">when invalide,the method will be called         * and tell you whether the content text is over size         *         * @param isOverSize         *            whether content text is over size         */         void onChanged(boolean isOverSize,Object Tag);    };}

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