Android 折叠头部监听

1、自定义scrollview,监听上下滑动距离：

public class ScrollListenerView extends ScrollView {
    private ScrollListener scrollViewListener = null;

    public ScrollListenerView(Context context) {
        super(context);
    }

    public ScrollListenerView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

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

    public void setScrollListener(ScrollListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }

    @Override
    protected void onScrollChanged(int x, int y, int oldX, int oldY) {
        super.onScrollChanged(x, y, oldX, oldY);
        if (scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, x, y, oldX, oldY);
        }
    }
}

接口

public interface ScrollListener {
    void onScrollChanged(ScrollListenerView scrollView, int x, int y, int oldX, int oldY);
}

2、activity实现接口

public class FriendDetailFragment extends SubBasicFragment implements ScrollListener {

private ScrollListenerView slv;

private int dp2_5;
private int dp37_5;
private int dp54;

slv.setScrollListener(this);

private void initMeasure() {
    nSdvWidth = UiUtils.dpToPx(77.5f, mContext.getResources());
    nSdvSmallWidth = UiUtils.dpToPx(40f, mContext.getResources());
    dp2_5 = UiUtils.dpToPx(2.5f, mContext.getResources());
    dp37_5 = UiUtils.dpToPx(37.5f, mContext.getResources());
    dp54 = UiUtils.dpToPx(54f, mContext.getResources());
}

@Override
public void onScrollChanged(ScrollListenerView scrollView, int x, int y, int oldX, int oldY) {
    animationViews(y);
}

//------------------------- 动画 start ------------------------

private void animationViews(int y) {
    int nStart = dp2_5;
    int nScaledY = nSdvWidth - y;

    if (y > nStart && y < dp37_5) {
        vMiddle.setVisibility(View.INVISIBLE);
        vRight.setVisibility(View.VISIBLE);
        UiUtils.setViewLayoutParams(sdvSurface, nScaledY, nScaledY);
    }
    if (y <= nStart) {
        vMiddle.setVisibility(View.VISIBLE);
        vRight.setVisibility(View.GONE);
        UiUtils.setViewLayoutParams(sdvSurface, nSdvWidth, nSdvWidth);
        setSideViewAlpha(1f);
    }
    if (y > dp2_5 && y < dp37_5) {
        float percent = ((float) (y - dp2_5)) / ((float) (dp37_5 - dp2_5));
        tvRightUserName.setTextSize(14f + 3.5f * percent);
        setSideViewAlpha(1 - percent - 0.3f);
    }
    if (y > dp54) {
        ivQrCode.setVisibility(View.GONE);
        ivUserInfo.setVisibility(View.GONE);
        vTop.setVisibility(View.VISIBLE);
        vTopBackground.setVisibility(View.VISIBLE);
        setViewBackground(R.drawable.selector_bt_back);
    } else {
        vTop.setVisibility(View.GONE);
        vTopBackground.setVisibility(View.GONE);
        setViewBackground(0);
    }
}

2.2工具方法：

public static int dpToPx(float dp, Resources resources) {
    float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.getDisplayMetrics());
    return (int) px;
}

/**
 * 重设 view 的宽高
 */
public static void setViewLayoutParams(View view, int nWidth, int nHeight) {
    ViewGroup.LayoutParams lp = view.getLayoutParams();
    if (lp.height != nHeight || lp.width != nWidth) {
        lp.width = nWidth;
        lp.height = nHeight;
        view.setLayoutParams(lp);
    }
}

private void setSideViewAlpha(float alpha) {
    ivQrCode.setAlpha(alpha);
    ivUserInfo.setAlpha(alpha);
    Log.i("lgq","ttt----"+alpha+"......."+ivQrCode.getVisibility());
    if (ivQrCode.getVisibility() != View.VISIBLE)
        ivQrCode.setVisibility(View.VISIBLE);
    if (ivUserInfo.getVisibility() != View.VISIBLE)
        ivUserInfo.setVisibility(View.VISIBLE);
}

xml文件

<com.zhenhua.online.view.scrollbylistener.ScrollListenerView
        android:id="@+id/slv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="none">

    <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

开始滑动