android自定义View 可上拉关闭的锁屏页

最近看到小米的锁屏页，如下图：

这是小米锁屏页面。上滑可以进入主页面或者是进入解锁，左滑可以进入相机。

然后就想写一个大概的，于是就开始动手了。

滑动的话，主要是用Scroller这个类来实现。我写得比较简单，只写了一个上滑进入解锁。

上代码：

/**
 * 作者：dls on 2016/9/26 11:05
 * 邮箱：[email protected]
 * 版本：1.0.0
 * 上拉遮罩层View  应用场景  手机锁屏  上拉解除锁屏 
 */
public class PullDoorView extends RelativeLayout{

    private Context mContext;

    private Scroller mScroller;

    private int mScreenHeight = 0;

    private int mLastDownY = 0;

    private int mCurryY;

    private int mDelY;

    private boolean mCloseFlag = false;

    private TextView mTvHint;

    private TextView mTvTime;

    private TextView mTvTimeDetail;

    private Handler handler;

    public PullDoorView(Context context) {
        super(context);
        this.mContext = context;
        initView();
    }

    public PullDoorView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.mContext = context;
        initView();
    }

    public PullDoorView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        this.mContext = context;
        initView();
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public PullDoorView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        this.mContext = context;
        initView();
    }

    private void initView(){

        // Interpolator  设置插值器  可弹跳
        Interpolator polator = new BounceInterpolator();
        mScroller = new Scroller(mContext, polator);

        // 获取屏幕分辨率
        WindowManager wm = (WindowManager) (mContext
                .getSystemService(Context.WINDOW_SERVICE));
        DisplayMetrics dm = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(dm);
        mScreenHeight = dm.heightPixels;

        // 这里你一定要设置成透明背景,不然会影响你看到底层布局
        this.setBackgroundColor(Color.argb(0, 0, 0, 0));

        mTvHint = new TextView(mContext);
        LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        params.bottomMargin = (int) mContext.getResources().getDimension(R.dimen.y20);  //这里我用到了自定义的屏幕适配  可以改成其他长度类型的数值
        params.addRule(RelativeLayout.CENTER_HORIZONTAL,-1);//-1 表示相对于父控件的位置
        params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM,-1);
        mTvHint.setText("上滑解锁");
        mTvHint.setTextColor(Color.WHITE);
        mTvHint.setTextSize(16);
        mTvHint.setLayoutParams(params);
        Animation ani = new AlphaAnimation(0f, 1f);
        ani.setDuration(1500);
        ani.setRepeatMode(Animation.REVERSE);
        ani.setRepeatCount(Animation.INFINITE);
        mTvHint.startAnimation(ani);
        addView(mTvHint);

        mTvTime = new TextView(mContext);
        params = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        params.topMargin = (int) mContext.getResources().getDimension(R.dimen.y40);
        params.leftMargin = (int) mContext.getResources().getDimension(R.dimen.x40);
        mTvTime.setTextColor(Color.WHITE);
        mTvTime.setTextSize((int) mContext.getResources().getDimension(R.dimen.x24));
        mTvTime.setLayoutParams(params);
        addView(mTvTime);

        mTvTimeDetail = new TextView(mContext);
        params = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
        params.topMargin = (int) mContext.getResources().getDimension(R.dimen.y130);
        params.leftMargin = (int) mContext.getResources().getDimension(R.dimen.x40);
        mTvTimeDetail.setTextColor(Color.WHITE);
        mTvTimeDetail.setTextSize((int) mContext.getResources().getDimension(R.dimen.x14));
        mTvTimeDetail.setLayoutParams(params);
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy年MM月dd日");
        String str=sdf.format(new Date());
        mTvTimeDetail.setText(str);
        addView(mTvTimeDetail);

        handler = new Handler() {//用于刷新显示时间
            public void handleMessage(Message msg) {
                mTvTime.setText((String)msg.obj);
            }
        };

        startShowTime();
    }

    //设置提示文字
    public void setText(String text){
        mTvHint.setText(text+"");
    }

    // 表层动画
    public void startBounceAnim(int startY, int dy, int duration) {
        mScroller.startScroll(0, startY, 0, dy, duration);
        invalidate();//这里必须调用invalidate()才能保证computeScroll()会被调用，否则不一定会刷新界面，看不到滚动效果
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int action = event.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                mLastDownY = (int) event.getY();
                return true;
            case MotionEvent.ACTION_MOVE:
                mCurryY = (int) event.getY();
                mDelY = mCurryY - mLastDownY;
                if (mDelY < 0) {
                    scrollTo(0, -mDelY);
                }
                break;
            case MotionEvent.ACTION_UP:
                mCurryY = (int) event.getY();
                mDelY = mCurryY - mLastDownY;
                if (mDelY < 0) {
                    if (Math.abs(mDelY) > mScreenHeight / 2) {
                        // 向上滑动超过半个屏幕高的时候 开启向上消失动画
                        startBounceAnim(this.getScrollY(), mScreenHeight, 450);
                        mCloseFlag = true;
                    } else {
                        // 向上滑动未超过半个屏幕高的时候 开启向下弹动动画
                        startBounceAnim(this.getScrollY(), -this.getScrollY(), 1000);
                        mCloseFlag = false;
                    }
                }

                break;
        }
        return super.onTouchEvent(event);
    }

    @Override
    public void computeScroll() {
        super.computeScroll();
        if (mScroller.computeScrollOffset()) {//判断滚动是否完成  true 表示动画还未完成
            scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
            postInvalidate();
        } else {
            if (mCloseFlag) {
                this.setVisibility(View.GONE);
            }
        }
    }

    public void startShowTime(){
        new Thread(){
            @Override
            public void run() {
                super.run();
                try {
                    while(true){
                        SimpleDateFormat sdf=new SimpleDateFormat("HH:mm:ss");
                        String str=sdf.format(new Date());
                        handler.sendMessage(handler.obtainMessage(100,str));
                        Thread.sleep(1000);
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }
}

	再贴上布局文件

xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/bg2">

            android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#ddd">