Java 使用RecyclerView添加到GridLayout中的动态按钮相互叠加
我想向网格布局添加动态按钮,如下所示每个按钮一次添加一个,布局必须自我更新才能使按钮成行我的问题是,当添加一个新按钮时,它会显示在最后添加的按钮的顶部,并且不会以行格式放置。在下面的图像中,我显示了我想要的内容和当前正在发生的事情,其中标有数字的方块是我的按钮。在我所拥有的图像中,我在布局中添加了6个按钮,但它们都位于彼此的顶部 我环顾了一下如何做到这一点,有人建议我使用Java 使用RecyclerView添加到GridLayout中的动态按钮相互叠加,java,android,dynamic,android-recyclerview,grid-layout,Java,Android,Dynamic,Android Recyclerview,Grid Layout,我想向网格布局添加动态按钮,如下所示每个按钮一次添加一个,布局必须自我更新才能使按钮成行我的问题是,当添加一个新按钮时,它会显示在最后添加的按钮的顶部,并且不会以行格式放置。在下面的图像中,我显示了我想要的内容和当前正在发生的事情,其中标有数字的方块是我的按钮。在我所拥有的图像中,我在布局中添加了6个按钮,但它们都位于彼此的顶部 我环顾了一下如何做到这一点,有人建议我使用RecyclerView和GridLayoutManager。我已经将此添加到代码中,但正如我所说的问题是,当我添加一个按钮
RecyclerView
和GridLayoutManager
。我已经将此添加到代码中,但正如我所说的问题是,当我添加一个按钮时,如果我添加另一个按钮,则第二个按钮将添加到第一个按钮的顶部。如果我的按钮是预设的,则我的功能有效,但不适用于动态按钮
这是我的密码:
主片段启动RecyclerView
。我还有另一个活动,它启动createButton()
方法并传递一个可绘制的and字符串。根据用户的操作,这些可绘图项和字符串一次一个地传递给此方法,并一次一个地创建图像按钮
public class MyFragment extends Fragment {
private GridLayoutManager lLayout;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
// onCreateView
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.my_fragment, container, false);
// Get screen size to have different layouts for phone and tablet
int screenSize = getResources().getConfiguration().screenLayout &
Configuration.SCREENLAYOUT_SIZE_MASK;
String toastMsg;
switch (screenSize) {
case Configuration.SCREENLAYOUT_SIZE_LARGE:
toastMsg = "Large screen";
Log.d("tag_name", "Large screen");
break;
case Configuration.SCREENLAYOUT_SIZE_NORMAL:
toastMsg = "Normal screen";
Log.d("tag_name", "Normal screen");
break;
case Configuration.SCREENLAYOUT_SIZE_SMALL:
toastMsg = "Small screen";
Log.d("tag_name", "Small screen");
break;
default:
toastMsg = "Screen size is neither large, normal or small";
Log.d("tag_name", "Screen size is not large, normal, or small");
}
Toast.makeText(getActivity(), toastMsg, Toast.LENGTH_LONG).show();
// Create an empty list to initialize the adapter (or else get nullPointerException error)
List<ItemObject> myList = new ArrayList<ItemObject>();
// 3 rows for tablet
// 2 rows for phone
if (screenSize == Configuration.SCREENLAYOUT_SIZE_LARGE
|| screenSize == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
lLayout = new GridLayoutManager(getActivity(), 3, GridLayoutManager.HORIZONTAL, false);
} else
lLayout = new GridLayoutManager(getActivity(), 2, GridLayoutManager.HORIZONTAL, false);
RecyclerView rView = (RecyclerView) view.findViewById(R.id.recycler_view);
rView.setHasFixedSize(true);
rView.setLayoutManager(lLayout);
RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(getActivity(), myList);
rView.setAdapter(rcAdapter);
return view;
}
private List<ItemObject> getAllItemList(String applicationName, Drawable app_drawable) {
List<ItemObject> allItems = new ArrayList<ItemObject>();
allItems.add(new ItemObject(applicationName, app_drawable));
return allItems;
}
public void createButton(Drawable d, String appName) {
List<ItemObject> rowListItem = getAllItemList(appName, d);
lLayout = new GridLayoutManager(getActivity(), 2, GridLayoutManager.HORIZONTAL, false);
RecyclerView rView = (RecyclerView) getView().findViewById(R.id.recycler_view);
rView.setHasFixedSize(true);
rView.setLayoutManager(lLayout);
RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(getActivity(), rowListItem);
rView.setAdapter(rcAdapter);
}
}
我的应用程序在创建第二个按钮时崩溃时出错:
05-11 17:05:25.275 14257-14257/it.anddev.bradipao.janus E/RecyclerView: No adapter attached; skipping layout
05-11 17:05:25.275 14257-14257/it.anddev.bradipao.janus D/AndroidRuntime: Shutting down VM
05-11 17:05:25.275 14257-14257/it.anddev.bradipao.janus W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x437c0160)
05-11 17:05:25.305 14257-14257/it.anddev.bradipao.janus E/AndroidRuntime: FATAL EXCEPTION: main
Process: it.anddev.bradipao.janus, PID: 14257
java.lang.NullPointerException
at android.support.v7.widget.RecyclerView.computeHorizontalScrollRange(RecyclerView.java:1518)
at android.view.View.onDrawScrollBars(View.java:12248)
at android.view.View.draw(View.java:14794)
at android.support.v7.widget.RecyclerView.draw(RecyclerView.java:3171)
at android.view.View.getDisplayList(View.java:13655)
at android.view.View.getDisplayList(View.java:13697)
at android.view.View.draw(View.java:14505)
at android.view.ViewGroup.drawChild(ViewGroup.java:3134)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2971)
at android.view.View.getDisplayList(View.java:13650)
at android.view.View.getDisplayList(View.java:13697)
at android.view.View.draw(View.java:14505)
at android.view.ViewGroup.drawChild(ViewGroup.java:3134)
at android.support.v7.widget.RecyclerView.drawChild(RecyclerView.java:3693)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2971)
at android.view.View.draw(View.java:14791)
at android.support.v7.widget.RecyclerView.draw(RecyclerView.java:3171)
at android.view.View.getDisplayList(View.java:13655)
at android.view.View.getDisplayList(View.java:13697)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3108)
at android.view.View.getDisplayList(View.java:13593)
at android.view.View.getDisplayList(View.java:13697)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3108)
at android.view.View.getDisplayList(View.java:13593)
at android.view.View.getDisplayList(View.java:13697)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3108)
at android.view.View.getDisplayList(View.java:13593)
at android.view.View.getDisplayList(View.java:13697)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3108)
at android.view.View.getDisplayList(View.java:13593)
at android.view.View.getDisplayList(View.java:13697)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3108)
at android.view.View.getDisplayList(View.java:13593)
at android.view.View.getDisplayList(View.java:13697)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3108)
at android.view.View.getDisplayList(View.java:13593)
at android.view.View.getDisplayList(View.java:13697)
at android.view.HardwareRenderer$GlRenderer.buildDisplayList(HardwareRenderer.java:1570)
at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:1449)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:2476)
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2300)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1929)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1043)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:771)
at android.view.Choreographer.doCallbacks(Choreographer.java:574)
at android.view.Choreographer.doFrame(Choreographer.java:544)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:757)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:149)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604)
at dalvik.system.NativeStart.main(Native Method)
做这样的事
public class MyFragment extends Fragment {
private GridLayoutManager lLayout;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
// onCreateView
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.my_fragment, container, false);
// Get screen size to have different layouts for phone and tablet
int screenSize = getResources().getConfiguration().screenLayout &
Configuration.SCREENLAYOUT_SIZE_MASK;
String toastMsg;
switch (screenSize) {
case Configuration.SCREENLAYOUT_SIZE_LARGE:
toastMsg = "Large screen";
Log.d("tag_name", "Large screen");
break;
case Configuration.SCREENLAYOUT_SIZE_NORMAL:
toastMsg = "Normal screen";
Log.d("tag_name", "Normal screen");
break;
case Configuration.SCREENLAYOUT_SIZE_SMALL:
toastMsg = "Small screen";
Log.d("tag_name", "Small screen");
break;
default:
toastMsg = "Screen size is neither large, normal or small";
Log.d("tag_name", "Screen size is not large, normal, or small");
}
Toast.makeText(getActivity(), toastMsg, Toast.LENGTH_LONG).show();
// Create an empty list to initialize the adapter (or else get nullPointerException error)
// 3 rows for tablet
// 2 rows for phone
if (screenSize == Configuration.SCREENLAYOUT_SIZE_LARGE
|| screenSize == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
lLayout = new GridLayoutManager(getActivity(), 3, GridLayoutManager.HORIZONTAL, false);
} else
lLayout = new GridLayoutManager(getActivity(), 2, GridLayoutManager.HORIZONTAL, false);
RecyclerView rView = (RecyclerView) view.findViewById(R.id.recycler_view);
rView.setHasFixedSize(true);
rView.setLayoutManager(lLayout);
rView.setAdapter(rcAdapter);
return view;
}
RecyclerViewAdapter rcAdapter;
private List<ItemObject> getAllItemList(String applicationName, Drawable app_drawable) {
List<ItemObject> allItems = new ArrayList<ItemObject>();
allItems.add(new ItemObject(applicationName, app_drawable));
return allItems;
}
public void createButton(Drawable d, String appName) {
rcAdapter.addItem(new ItemObject(appName , d))
}
}
编辑
要防止出现警告,请尝试将适配器初始化移动到onCreate
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
List<ItemObject> myList = new ArrayList<ItemObject>();
rcAdapter = new RecyclerViewAdapter(getActivity(), myList);
}
@覆盖
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
List myList=new ArrayList();
rcAdapter=新的RecycleServiceAdapter(getActivity(),myList);
}
创建按钮时,您只需做两件事:
Notify…()
方法之一通知适配器数据已更改(有,使用最适用的方法)public void addItem(ItemObject item) {
mList.add(item);
notifyItemInserted(mList.size() - 1);
}
无关:在Android上,您可以使用资源解析系统来确定要显示的列数 生成
src/main/res/values/integers.xml
并添加:
<resources>
<integer name="grid_column_count">2</integer>
</resources>
<resources>
<integer name="grid_column_count">3</integer>
</resources>
请注意-large
,它将通知系统此大小及以上的屏幕应使用此备用资源值。现在,您可以在片段中简单地编写:
int columnCount = getResources().getInteger(R.integer.grid_column_count);
GridLayoutManager layout = new GridLayoutManager(getActivity(), columnCount,
GridLayoutManager.HORIZONTAL, false);
我之所以提到这一点,是因为屏幕大小桶(大的)可能不是确定列数的最佳方法。您可能更适合使用屏幕宽度限定符(例如
-w600dp
),该限定符将在设备旋转时更新(而在该场景中,大小桶不会改变)。您可以阅读有关资源限定符的更多信息。我发现,每次您不需要创建按钮时,您都在重新初始化recyclerView,结果是使用该按钮创建了一个新的recyclerView。@varunkr我明白了!所以我想我每次都是在MyFragment的createButton方法中初始化recyclerView,对吗?所以,你知道我如何将代码更改为更新,而不是每次都创建一个新的recyclerView吗?看看我的答案谢谢!对于我的addItem,我必须使用以下代码:“public void addItem(ItemObject项){mList.add(item);notifyItemInserted(mList.size()-1);}”,这样我就不会出错,并且可以构建我的gradle。当我为我的图像按钮获取第一个图像时,我会收到警告“未连接适配器:跳过布局”,但我的图像按钮创建得很好。但是当我尝试在布局中添加第二个图像按钮时,我得到了相同的警告,并且我的应用程序崩溃,出现了nullPointerException。你能看到什么明显的原因吗?@Natalie你能引用一个确切的空指针异常吗?如果我将适配器初始化添加到onCreate,那么u getIt无法消除错误,但我确实更新了我的问题以显示错误。我必须试着找出抛出“null”的原因,因为我的stackTrace现在没有告诉我太多。@Natalie你是如何从活动中调用这个createButton方法的?您之前所做的与您现在所做的不同之处在于,现在您的“创建”按钮不会像之前那样初始化recyclerView和适配器。由于此原因,您可能会遇到异常,因为您的适配器etc第二次可能仍处于未初始化状态。这取决于您如何启动片段以及如何从活动中调用此createButton。你能发布活动代码吗。这可能会解决问题!!我更新了问题的“编辑”部分,以显示我是如何开始我的片段的。我在这里称它的方式与我在发布的另一个问题中的方式不同,因为在创建第一个图像按钮时,这导致了NullPointerException,而现在它发生在第二个图像按钮上,但可能这一切都源于我错误初始化片段的相同问题?谢谢!关于更新我的适配器:当我为我的图像按钮获取第一个图像时,我会收到警告“未连接适配器:跳过布局”,但我的图像按钮创建得很好。但是当我尝试在布局中添加第二个图像按钮时,我得到了相同的警告,并且我的应用程序崩溃,出现了nullPointerException。你能看到什么明显的原因吗?@Natalie如果你不能解决这个问题,最好发布一个单独的问题,包括Logcat的整个堆栈跟踪
public void addItem(ItemObject item) {
mList.add(item);
notifyItemInserted(mList.size() - 1);
}
<resources>
<integer name="grid_column_count">2</integer>
</resources>
<resources>
<integer name="grid_column_count">3</integer>
</resources>
int columnCount = getResources().getInteger(R.integer.grid_column_count);
GridLayoutManager layout = new GridLayoutManager(getActivity(), columnCount,
GridLayoutManager.HORIZONTAL, false);