我有一个带有四个网格元素（2 * 2）的recyclerview，就像菜单一样。但是，当我点击它们时，没有显示涟漪效果。它只是带我到下一个活动，没有任何视觉确认按下视图。有人可以帮忙吗？
MainActivity
public class MainActivity extends AppCompatActivity implements MainMenuAdapter.OnItemClickListener {
Toolbar toolbar;
private static List<ViewModel> tileItems = new ArrayList<>();
static {
tileItems.add(new ViewModel("Activity", "#3F51B5", R.drawable.activity));
tileItems.add(new ViewModel("Profile", "#E91E63", R.drawable.profile));
tileItems.add(new ViewModel("Training", "#FF5722", R.drawable.training));
tileItems.add(new ViewModel("Diet", "#4CAF50", R.drawable.diet));
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
MainAdapter adapter = new MainAdapter(tileItems, MainActivity.this);
recyclerView.setAdapter(adapter);
adapter.setOnItemClickListener(this);
// Toolbar
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}
@Override
public void onBackPressed() {
this.moveTaskToBack(true);
// this.finishAffinity();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override public void onItemClick(View view, ViewModel viewModel) {
}
}
MainAdapter
public class MainAdapter extends RecyclerView.Adapter<MainMenuAdapter.ViewHolder> implements View.OnClickListener {
private List<ViewModel> items;
private OnItemClickListener onItemClickListener;
private Context context;
// Adapter constructor
public MainAdapter(List<ViewModel> items, Context context) {
this.items = items;
this.context = context;
}
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.main_item, parent, false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
final ViewModel dataItem = items.get(position);
viewHolder.colorBlock.setBackgroundColor(dataItem.getColor());
viewHolder.menuName.setText(dataItem.getName());
viewHolder.menuIcon.setImageResource(dataItem.getImage());
viewHolder.itemView.setTag(dataItem);
if (dataItem.getActivity() != null) {
viewHolder.colorBlock.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent i = new Intent(context, dataItem.getActivity());
context.startActivity(i);
}
});
}
}
@Override
public int getItemCount() {
return items.size();
}
@Override public void onClick(final View v) {
// Give some time to the ripple to finish the effect
if (onItemClickListener != null) {
new Handler().postDelayed(new Runnable() {
@Override public void run() {
onItemClickListener.onItemClick(v, (ViewModel) v.getTag());
}
}, 200);
}
}
/** This is our ViewHolder class */
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView menuName;
public View colorBlock;
public ImageView menuIcon;
public ViewHolder(View convertView) {
super(convertView); // Must call super() first
menuName = (TextView) convertView.findViewById(R.id.menuName);
colorBlock = (View) convertView.findViewById(R.id.colorBlock);
menuIcon = (ImageView) convertView.findViewById(R.id.menuItem);
}
}
public interface OnItemClickListener {
void onItemClick(View view, ViewModel viewModel);
}
}
activity_main.xml中
<RelativeLayout
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=".MainActivity">
<include
android:id="@+id/toolbar"
layout="@layout/toolbar"
android:layout_height="wrap_content"
android:layout_width="match_parent"/>
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_below="@id/toolbar"
android:layout_width= "match_parent"
android:layout_height = "match_parent" />
</RelativeLayout>
main_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
android:focusable="true"
android:foreground="?android:attr/selectableItemBackground">
<View
android:id="@+id/colorBlock"
android:layout_width="match_parent"
android:layout_height="170dp" />
<ImageView
android:id="@+id/menuItem"
android:layout_width="120dp"
android:layout_height="120dp"
android:layout_centerHorizontal="true"
android:padding="16dp"
/>
<TextView
android:id="@+id/menuName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="16dp"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
android:textColor="@android:color/white"
android:textSize="16sp"/>
</RelativeLayout>
答案 0 :(得分：14)
如果将main_item.xml的背景设置为?android:selectableItemBackground或?selectableItemBackground，则会发生Ripple效果（@Budius在评论中出错）。我找到了对第二个的引用。但是，AndroidStudio警告它在com.android.support:design中是私有的。尝试使用该私有版本时，我的应用程序崩溃了。我猜到第一个用＆＃34; android：＆＃34;前缀，瞧，它有效。
也许您意外地设置了android:foreground？我试过了，但看到我的RecyclerView项目没有发生任何事情。
您更新的RelativeLayout将是：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
android:focusable="true"
android:foreground="?android:attr/selectableItemBackground"
android:background="?android:selectableItemBackground">
我也看到android:background="?android:attr/selectableItemBackground"努力发起涟漪。我还要提到selectableItemBackground不需要位于main_item.xml的根元素上。我在根项目中使用背景颜色，然后在嵌套的ViewGroup上设置selectableItemBackground。
我的答案来自参考框架，不使用材料设计appcompat。我怀疑如果您使用材料设计appcompat支持库会有所不同。