Android 仿京东淘宝 商品详情页 商品图片效果

最近重构商品，产品要求，按照淘宝京东来。。。。

成品如图这个效果



思路就是监听外边ScrollView的滑动监听，然后给上边图片设置margin，二话不说上代码

简单的界面布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<com.zhangd.zhangdtest.view.MyScrollView
android:id="@+id/scrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#fff">

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/im_top"
android:layout_width="match_parent"
android:layout_height="300dp"
android:scaleType="fitXY"
android:src="@drawable/image"/>
</RelativeLayout>

<TextView
android:layout_width="match_parent"
android:layout_height="40dp"
android:text="11111"
android:gravity="center"/>
<View style="@style/line"/>
<TextView
android:layout_width="match_parent"
android:layout_height="40dp"
android:text="11111"
android:gravity="center"/>
<View style="@style/line"/>
......

</LinearLayout>

</com.zhangd.zhangdtest.view.MyScrollView>

</LinearLayout>

因为Scrollview没有直接的监听滑动距离的方法，只能自己重写一个简单的MyScrollView，通过重写onScrollChanged方法来实时获取滑动的距离
MyScrollView.java

public class MyScrollView extends ScrollView {
private ScrollViewListener scrollViewListener = null;

public interface ScrollViewListener {
void onScrollChanged(int y);
}

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

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

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

public void setScrollViewListener(ScrollViewListener 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(y);
}
}
}

然后界面Activity里边，通过比较滑动的距离和图片的高，在滑动的距离比图片高度小的时候，设置图片的margin
public class ScrollViewActivity1 extends BaseActivity implements MyScrollView.ScrollViewListener {

private ImageView im_top;
private MyScrollView scrollView;
private int imageHeight;
@Override
public void setContentView() {
setContentView(R.layout.activity_scroll1);
}

@Override
protected void findViewById() {
im_top = (ImageView) findViewById(R.id.im_top);
scrollView = (MyScrollView) findViewById(R.id.scrollView);

im_top.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
imageHeight = im_top.getHeight();
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
im_top.getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
im_top.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
}
});

// 设置滑动监听
scrollView.setScrollViewListener(this);

}

@Override
protected void initView() {

}

/**
* 滑动回调
* @param y
*/
@Override
public void onScrollChanged(int y) {
if (y < imageHeight) {
setMargins(im_top, 0, y / 2, 0, -y / 2);
}
}

public static void setMargins (View v, int l, int t, int r, int b) {
if (v.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) v.getLayoutParams();
p.setMargins(l, t, r, b);
v.requestLayout();
}
}
}

OK鸟