我有一个 RecyclerView
,每行都有一个图标。图标应该动态着色,所以我使用白色图标并在绑定(bind) View 时应用颜色过滤器。奇怪的是,我最终在结果 View 中发现了很多差异。
在这个例子中,我尝试将每三行设置为红色,其余行设置为绿色(注释 #18):
下面是适配器。如您所见,每次我重新绑定(bind) holder 时,我都会将更改后的图标应用于 ImageView
,大概没有为旧的回收图像留出空间。
public class TestAdapter extends RecyclerView.Adapter<TestAdapter.ViewHolder> {
private final Context context;
public TestAdapter(Context context) {
this.context = context;
}
@Override
public TestAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false);
return new ViewHolder(itemView);
}
@Override
public void onBindViewHolder(TestAdapter.ViewHolder holder, int position) {
holder.bindItem(position);
}
@Override
public int getItemCount() {
return 200;
}
public class ViewHolder extends RecyclerView.ViewHolder {
private final ImageView image;
private final TextView text;
public ViewHolder(View itemView) {
super(itemView);
image = (ImageView) itemView.findViewById(R.id.image);
text = (TextView) itemView.findViewById(R.id.text);
}
public void bindItem(int position) {
// pick color depending on the position
final int color = ContextCompat.getColor(context,
position%3 == 0 ? android.R.color.holo_red_light : android.R.color.holo_green_light
);
// set text content and color
text.setText("#" + position);
text.setTextColor(color);
// create icon from the resource and set filter
final Drawable icon = ResourcesCompat.getDrawable(context.getResources(), R.drawable.ic_brightness, null);
icon.setColorFilter(color, PorterDuff.Mode.MULTIPLY);
image.setImageDrawable(icon);
}
}
}
item_layout.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:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/image"
android:layout_width="18dp"
android:layout_height="wrap_content"
android:scaleType="fitStart"
android:adjustViewBounds="true" />
<TextView
android:id="@+id/text"
android:textSize="18sp"
android:textColor="@android:color/black"
android:layout_marginLeft="48dp"
android:layout_marginStart="48dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_vertical"
tools:text="text" />
</LinearLayout>
什么给了?
谢谢。
最佳答案
看了你的评论,不知道是否符合你的要求。但是,我能够通过在布局文件中使用 android:src
元素设置可绘制的“亮度”来复制预期的行为,然后将过滤器应用于 ImageView
(而不是图标):
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
public RecyclerViewAdapter() {
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.rv_row, viewGroup, false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, int i) {
viewHolder.bindItem(i);
}
@Override
public int getItemCount() {
return 200;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private final ImageView image;
private final TextView text;
public ViewHolder(View itemView) {
super(itemView);
image = (ImageView) itemView.findViewById(R.id.image);
text = (TextView) itemView.findViewById(R.id.text);
}
public void bindItem(int position) {
final int color = ContextCompat.getColor(itemView.getContext(),
position % 3 == 0 ? android.R.color.holo_red_light : android.R.color.holo_green_light
);
text.setText("#" + position);
text.setTextColor(color);
image.setColorFilter(color, PorterDuff.Mode.MULTIPLY);
}
}
}
编辑:
如果您动态设置图标,但将滤镜应用于 ImageView
,它也有效:
public static class ViewHolder extends RecyclerView.ViewHolder {
private final ImageView image;
private final TextView text;
public ViewHolder(View itemView) {
super(itemView);
image = (ImageView) itemView.findViewById(R.id.image);
text = (TextView) itemView.findViewById(R.id.text);
}
public void bindItem(int position) {
final int color = ContextCompat.getColor(itemView.getContext(),
position % 3 == 0 ? android.R.color.holo_red_light : android.R.color.holo_green_light
);
text.setText("#" + position);
text.setTextColor(color);
Drawable icon = getIcon();
image.setImageDrawable(icon);
image.setColorFilter(color, PorterDuff.Mode.MULTIPLY);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private Drawable getIcon() {
return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
? image.getContext().getResources().getDrawable(R.drawable.ic_brightness_1_white_24dp, null)
: image.getContext().getResources().getDrawable(R.drawable.ic_brightness_1_white_24dp);
}
}
关于android - RecyclerView 中不正确的图像回收,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34632812/