Android 折叠头部监听，抽屉式动画

实现方法2：https://blog.csdn.net/meixi_android/article/details/84136375

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;}@Overrideprotected 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.ScrollListenerViewandroid:id="@+id/slv"android:layout_width="match_parent"android:layout_height="match_parent"android:scrollbars="none"><LinearLayoutandroid:orientation="vertical"android:layout_width="match_parent"android:layout_height="wrap_content">