HorizontalListView 缩放内容(项目布局)
HorizontalListView scaling content (items layouts)
我正在尝试创建一个 HorizontalListView(by DevSmart)
,其中第一项(列)的宽度为 Ndp
,所有下一项的宽度为 N/2dp
。在我的示例中 N = 300
。所以我完美地完成了标准 Android ListView 并且效果很好。但是遵循与 HorizontalListView 完全相同的逻辑,我面临着误解。
All items have same width and height as HorizontalListView. It
doesen't matter what width/height i specify in photo.xml
.
And as a result i get items wide and tall for whole screen (because my com.example.yura.listviewscale.HorizontalListView
has match_parent
for width and height)
有人可以帮我吗?
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.yura.listviewscale.MainActivity" >
<com.example.yura.listviewscale.HorizontalListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/myHzListView" />
</LinearLayout>
photo.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parnet"
android:layout_height="match_parent"
android:id="@+id/photoView" />
</RelativeLayout>
适配器存根 class:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.photo, parent, false);
viewHolder = new ViewHolder();
viewHolder.photoImageView = (ImageView) convertView.findViewById(R.id.photoView);
mInitialWidth = convertView.getLayoutParams().height;
convertView.setTag(viewHolder);
} else
viewHolder = (ViewHolder)convertView.getTag();
Photo photo = mPhotoList.get(position);
if (position != 0) {
RelativeLayout.LayoutParams params = convertView.getLayoutParams();
params.width = (int) (mInitialWidth * 0.5f);
}
viewHolder.photoImageView.setBackgroundDrawable(photo.getDrawable());
return convertView;
}
static final class ViewHolder {
ImageView photoImageView;
}
使用带有自定义 LayoutManager 的 RecyclerView 解决了这个问题。在 onLayoutChildren 方法中执行所有魔术。尤其是测量所有视图和布局。
我正在尝试创建一个 HorizontalListView(by DevSmart)
,其中第一项(列)的宽度为 Ndp
,所有下一项的宽度为 N/2dp
。在我的示例中 N = 300
。所以我完美地完成了标准 Android ListView 并且效果很好。但是遵循与 HorizontalListView 完全相同的逻辑,我面临着误解。
All items have same width and height as HorizontalListView. It doesen't matter what width/height i specify in
photo.xml
. And as a result i get items wide and tall for whole screen (because mycom.example.yura.listviewscale.HorizontalListView
hasmatch_parent
for width and height)
有人可以帮我吗?
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.yura.listviewscale.MainActivity" >
<com.example.yura.listviewscale.HorizontalListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/myHzListView" />
</LinearLayout>
photo.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parnet"
android:layout_height="match_parent"
android:id="@+id/photoView" />
</RelativeLayout>
适配器存根 class:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.photo, parent, false);
viewHolder = new ViewHolder();
viewHolder.photoImageView = (ImageView) convertView.findViewById(R.id.photoView);
mInitialWidth = convertView.getLayoutParams().height;
convertView.setTag(viewHolder);
} else
viewHolder = (ViewHolder)convertView.getTag();
Photo photo = mPhotoList.get(position);
if (position != 0) {
RelativeLayout.LayoutParams params = convertView.getLayoutParams();
params.width = (int) (mInitialWidth * 0.5f);
}
viewHolder.photoImageView.setBackgroundDrawable(photo.getDrawable());
return convertView;
}
static final class ViewHolder {
ImageView photoImageView;
}
使用带有自定义 LayoutManager 的 RecyclerView 解决了这个问题。在 onLayoutChildren 方法中执行所有魔术。尤其是测量所有视图和布局。