原有思路:

• View.Post() 方式

  說明:將處理添加到主線程隊(duì)列中,等待處理,會(huì)有顯示慢的問題,由于View的復(fù)用,當(dāng)列表滑動(dòng)后,就不能正確返回相關(guān)值了.

• getViewTreeObserver().addOnGlobalLayoutListener()

  說明:添加全局View 變化監(jiān)聽,會(huì)被多次調(diào)用,并且在列表滑動(dòng)過程中,跟View.Post() 有相同的問題.

新思路

• onDraw()
• onLayout()
• onMeasure() 中進(jìn)行獲取對(duì)應(yīng)TextView 的getLineCount()

View 的繪制過程為 onMeasure()->onLayout()->onDraw()

所以將處理邏輯放置到 onMeasure()中.

說明:

• 封裝 容器 CommendContainerView,繼承 RelativeLayout
• 重寫 onMeasure()方法,當(dāng) super.onMeasure(widthMeasureSpec, heightMeasureSpec); 執(zhí)行完后, 容器已經(jīng)知道了所有子View 的相關(guān)尺寸, 這個(gè)時(shí)候 可以去進(jìn)行判斷了.并且不會(huì)有延時(shí)問題.
• 進(jìn)行邏輯判斷后,調(diào)用 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 對(duì)子View 再進(jìn)行一次測(cè)量.保證顯示邏輯.
• 針對(duì)于 用戶操作過的 View, 將狀態(tài)進(jìn)行緩存.

下面直接上代碼:

public class CommendContainerView extends RelativeLayout {

    private TextView mCommendTextView;
    private TextView mCommendFun;
    private CommendShowFunListener mListener;

    private boolean mFlag = true;
    private int mLinesLimit = 1;
    private Boolean mShowAll;
    private int mPos;

    public CommendContainerView(Context context) {
        this(context, null);
    }

    public CommendContainerView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CommendContainerView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initView(context, attrs, defStyleAttr);
    }

    //初始化布局~
    private void initView(Context context, AttributeSet attrs, int defStyleAttr) {
        inflate(context, R.layout.view_commend_container, this);
        mCommendTextView = findViewById(R.id.commend_ctv_commend);
        mCommendFun = findViewById(R.id.commend_tv_fun);
        mCommendFun.setOnClickListener(onClickListener);
    }

    public void setCommendInfo(CharSequence text, Boolean showAll, int pos) {
        mShowAll = showAll;
        mPos = pos;
        if (null != mShowAll) {
            mFlag = true;
            mCommendFun.setVisibility(VISIBLE);
            if (mShowAll) {
                mCommendFun.setText(R.string.desc_shrinkup);
                mCommendTextView.setMaxLines(Integer.MAX_VALUE);
            } else {
                mCommendFun.setText(R.string.desc_spread);
                mCommendTextView.setMaxLines(mLinesLimit);
            }
            mCommendTextView.setText(text);
        } else {
            mFlag = false;
            mCommendFun.setVisibility(GONE);
            mCommendTextView.setMaxLines(Integer.MAX_VALUE);
            mCommendTextView.setText(text);
        }
    }

    private OnClickListener onClickListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            mCommendFun.setVisibility(VISIBLE);
            mFlag = true;
            if (null == mShowAll || !mShowAll) {
                mCommendTextView.setMaxLines(Integer.MAX_VALUE);
                mCommendFun.setText(R.string.desc_shrinkup);
                mShowAll = true;
            } else {
                mCommendTextView.setMaxLines(mLinesLimit);
                mCommendFun.setText(R.string.desc_spread);
                mShowAll = false;
            }
            if (null != mListener) {
                mListener.onShowStatusChange(mPos, mShowAll);
            }
        }
    };

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (!mFlag) {
            mFlag = true;
            if (mCommendTextView.getLineCount() > mLinesLimit) {
                //超過行數(shù)~
                mCommendFun.setVisibility(VISIBLE);
                mCommendFun.setText(R.string.desc_spread);
                mCommendTextView.setMaxLines(mLinesLimit);
            } else {
                mCommendFun.setVisibility(GONE);
                mCommendTextView.setMaxLines(Integer.MAX_VALUE);
            }
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    public void setCommendShowFunListener(CommendShowFunListener listener) {
        this.mListener = listener;
    }

    public void setLinesLimit(int limit) {
        this.mLinesLimit = limit;
    }

    interface CommendShowFunListener {
        void onShowStatusChange(int pos, boolean showAll);
    }

}