private void startMarquee() {
        // Do not ellipsize EditText
        if (getKeyListener() != null) return;

        if (compressText(getWidth() - getCompoundPaddingLeft() - getCompoundPaddingRight())) {
            return;
        }
		
		// 1、跑馬燈控制類(lèi)沒(méi)有創(chuàng)建或者跑馬燈效果已經(jīng)停止
        if ((mMarquee == null || mMarquee.isStopped()) && 
        // 2、當(dāng)前Textview是獲取到焦點(diǎn)或者被選中狀態(tài)
        (isFocused() || isSelected())
        // 3、文本的行數(shù)只有一行
         && getLineCount() == 1
         // 4、文本長(zhǎng)度大于Textview的寬度 
         && canMarquee()) {

            if (mMarqueeFadeMode == MARQUEE_FADE_SWITCH_SHOW_ELLIPSIS) {
                mMarqueeFadeMode = MARQUEE_FADE_SWITCH_SHOW_FADE;
                final Layout tmp = mLayout;
                mLayout = mSavedMarqueeModeLayout;
                mSavedMarqueeModeLayout = tmp;
                setHorizontalFadingEdgeEnabled(true);
                requestLayout();
                invalidate();
            }

            if (mMarquee == null) mMarquee = new Marquee(this);
            mMarquee.start(mMarqueeRepeatLimit);
        }
    }
    
     private boolean canMarquee() {
        int width = mRight - mLeft - getCompoundPaddingLeft() - getCompoundPaddingRight();
        return width > 0 && (mLayout.getLineWidth(0) > width
                || (mMarqueeFadeMode != MARQUEE_FADE_NORMAL && mSavedMarqueeModeLayout != null
                        && mSavedMarqueeModeLayout.getLineWidth(0) > width));
    }

public class MarqueeTextView extends TextView {

    public MarqueeTextView(Context context) {
        super(context);
        initView(context);
    }

    public MarqueeTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initView(context);
    }

    public MarqueeTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initView(context);
    }

    private void initView(Context context) {
        this.setEllipsize(TextUtils.TruncateAt.MARQUEE);
        this.setSingleLine(true);
        this.setMarqueeRepeatLimit(-1);
    }

    //最關(guān)鍵的部分
    public boolean isFocused() {
        return true;
    }
}

 <com.example.MarqueeTextView
        android:id="@+id/tv"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/show_float"
        android:layout_marginTop="20dp"
        android:padding="10dp"
        android:text="歡迎來(lái)到跑馬燈高端玩家局，這是高端玩法示例~"
        android:textColor="@color/white"
        android:background="@drawable/com_live_rounded_rectangle"/>

       void start(int repeatLimit) {
       //重復(fù)次數(shù)設(shè)置0，那就直接停止跑馬燈
            if (repeatLimit == 0) {
                stop();
                return;
            }
           //...省略掉大部分不相關(guān)的代碼
                mChoreographer.postFrameCallback(mStartCallback);
            }
        }
       
      private Choreographer.FrameCallback mStartCallback = new Choreographer.FrameCallback() {
            @Override
            public void doFrame(long frameTimeNanos) {
                mStatus = MARQUEE_RUNNING;
                mLastAnimationMs = mChoreographer.getFrameTime();
                tick();
            }
        };
 
       void tick() {
            if (mStatus != MARQUEE_RUNNING) {
                return;
            }

            if (textView != null && (textView.isFocused() || textView.isSelected())) {
                long currentMs = mChoreographer.getFrameTime();
                long deltaMs = currentMs - mLastAnimationMs;
                mLastAnimationMs = currentMs;
                float deltaPx = deltaMs * mPixelsPerMs;
                mScroll += deltaPx;
                //要是跑馬燈滾動(dòng)的距離大于最大距離，那么回到給mRestartCallback
                if (mScroll > mMaxScroll) {
                    mScroll = mMaxScroll;
                    mChoreographer.postFrameCallbackDelayed(mRestartCallback, MARQUEE_DELAY);
                } else {
                    mChoreographer.postFrameCallback(mTickCallback);
                }
                textView.invalidate();
            }
        }
        
         private Choreographer.FrameCallback mRestartCallback = new Choreographer.FrameCallback() {
            @Override
            public void doFrame(long frameTimeNanos) {
                if (mStatus == MARQUEE_RUNNING) {
                    if (mRepeatLimit >= 0) {
                        mRepeatLimit--;
                    }
                    start(mRepeatLimit);
                }
            }
        }

public class MarqueeTextView extends androidx.appcompat.widget.AppCompatTextView {
    private Choreographer.FrameCallback mRealRestartCallbackObj;
    private Choreographer.FrameCallback mFakeRestartCallback;
    private OnShowTextListener mOnShowTextListener;

    public MarqueeTextView(Context context, OnShowTextListener onShowTextListener) {
        super(context);
        initView(context);
        this.mOnShowTextListener = onShowTextListener;

    }

    public MarqueeTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initView(context);
    }

    public MarqueeTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initView(context);
    }


    private void initView(Context context) {
        //繞過(guò)隱藏api的限制
        Reflection.unseal(context.getApplicationContext());

        //設(shè)置跑馬燈生效條件
        this.setEllipsize(TextUtils.TruncateAt.MARQUEE);
        this.setSingleLine(true);
        this.setFocusable(true);

        //反射設(shè)置跑馬燈監(jiān)聽(tīng)
        try {
            //從TextView類(lèi)中找到定義的字段mMarquee
            Field marqueeField = ReflectUtil.getDeclaredField(TextView.class, "mMarquee");
            //獲取Marquee類(lèi)的構(gòu)造方法Marquee(TextView v)
            Constructor declaredConstructor = ReflectUtil.getDeclaredConstructor(Class.forName("android.widget.TextView$Marquee"), TextView.class);
            //實(shí)例化一個(gè)Marquee對(duì)象，傳入?yún)?shù)是Textview對(duì)象
            Object marqueeObj = declaredConstructor.newInstance(this);
            //從Marquee類(lèi)中找到定義的字段mRestartCallback，重新開(kāi)始一輪跑馬燈時(shí)候會(huì)回調(diào)到這個(gè)對(duì)象doFrame（）方法
            Field restartCallbackField = ReflectUtil.getDeclaredField(Class.forName("android.widget.TextView$Marquee"), "mRestartCallback");
            //從Marquee實(shí)例對(duì)象中獲取到真實(shí)的mRestartCallback對(duì)象
            mRealRestartCallbackObj = (Choreographer.FrameCallback) restartCallbackField.get(marqueeObj);
            //構(gòu)造一個(gè)假的mRestartCallback對(duì)象，用來(lái)監(jiān)聽(tīng)什么時(shí)候跑完一輪跑馬燈效果
            mFakeRestartCallback = new Choreographer.FrameCallback() {
                @Override
                public void doFrame(long frameTimeNanos) {
                    //這里還是執(zhí)行真實(shí)的mRestartCallback對(duì)象的代碼邏輯
                    mRealRestartCallbackObj.doFrame(frameTimeNanos);
                    Log.i("min77","跑馬燈文本顯示完畢");
                    //回調(diào)通知跑完一輪
                    if(MarqueeTextView.this.mOnShowTextListener != null){
                        MarqueeTextView.this.mOnShowTextListener.onComplete(0);
                    }

                }
            };
            //把假的mRestartCallback對(duì)象設(shè)置給Marquee對(duì)象，其實(shí)就是代理模式
            restartCallbackField.set(marqueeObj, mFakeRestartCallback);
            //把自己實(shí)例化的Marquee對(duì)象設(shè)置給Textview
            marqueeField.set(this, marqueeObj);


        } catch (Exception e) {
            e.printStackTrace();
            Log.e("min77",e.getMessage());
        }
    }



    //最關(guān)鍵的部分
    public boolean isFocused() {
        return true;
    }

    /**
     * 是否顯示完整文本
     */
    public interface OnShowTextListener{
        void onComplete(int delayMillisecond);

    }

}