java.lang.ClassCastException：无法使用 ArrayAdapter 将 android.widget.LinearLayout 转换为 android.widget.TextView
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时间：2020-08-13 00:52:50 来源:igfitidea点击:
java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.TextView using ArrayAdapter
提问by Pandarian Ld
I'm working on my term project which developed on Android device. The problem is I try to add an object into my ArrayAdapter. But it gets an errors.
我正在从事我在 Android 设备上开发的学期项目。问题是我尝试将一个对象添加到我的 ArrayAdapter 中。但它得到一个错误。
11-29 11:58:07.136: D/dalvikvm(1262): GC_FOR_ALLOC freed 136K, 8% free 2677K/2880K, paused 30ms, total 32ms
11-29 11:58:07.415: E/ArrayAdapter(1262): You must supply a resource ID for a TextView
11-29 11:58:07.415: D/AndroidRuntime(1262): Shutting down VM
11-29 11:58:07.415: W/dalvikvm(1262): threadid=1: thread exiting with uncaught exception (group=0x41465700)
11-29 11:58:07.465: E/AndroidRuntime(1262): FATAL EXCEPTION: main
11-29 11:58:07.465: E/AndroidRuntime(1262): java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:386)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.AbsListView.obtainView(AbsListView.java:2177)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ListView.makeAndAddView(ListView.java:1840)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ListView.fillDown(ListView.java:675)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ListView.fillFromTop(ListView.java:736)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ListView.layoutChildren(ListView.java:1655)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.AbsListView.onLayout(AbsListView.java:2012)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.View.layout(View.java:14289)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewGroup.layout(ViewGroup.java:4562)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.View.layout(View.java:14289)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewGroup.layout(ViewGroup.java:4562)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.View.layout(View.java:14289)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewGroup.layout(ViewGroup.java:4562)
11-29 11:58:07.465: E/AndroidRuntime(1262): at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:349)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.View.layout(View.java:14289)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewGroup.layout(ViewGroup.java:4562)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.View.layout(View.java:14289)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewGroup.layout(ViewGroup.java:4562)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1976)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1730)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.Choreographer.doFrame(Choreographer.java:532)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.os.Handler.handleCallback(Handler.java:730)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.os.Handler.dispatchMessage(Handler.java:92)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.os.Looper.loop(Looper.java:137)
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.app.ActivityThread.main(ActivityThread.java:5103)
11-29 11:58:07.465: E/AndroidRuntime(1262): at java.lang.reflect.Method.invokeNative(Native Method)
11-29 11:58:07.465: E/AndroidRuntime(1262): at java.lang.reflect.Method.invoke(Method.java:525)
11-29 11:58:07.465: E/AndroidRuntime(1262): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
11-29 11:58:07.465: E/AndroidRuntime(1262): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-29 11:58:07.465: E/AndroidRuntime(1262): at dalvik.system.NativeStart.main(Native Method)
11-29 11:58:07.465: E/AndroidRuntime(1262): Caused by: java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.TextView
11-29 11:58:07.465: E/AndroidRuntime(1262): at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:379)
11-29 11:58:07.465: E/AndroidRuntime(1262): ... 40 more
This is my MainActivity - onCreate method.
这是我的 MainActivity - onCreate 方法。
private EditText createTaskText;
ArrayAdapter<Task> listAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); // To change body of overridden
// methods use File | Settings |
// File Templates.
setContentView(R.layout.main);
// !!! Add quick create task !!!
createTaskText = (EditText) findViewById(R.id.quickTopic);
TextView.OnEditorActionListener exListener = new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int actionId,
KeyEvent event) {
if (actionId == EditorInfo.IME_NULL
&& event.getAction() == KeyEvent.ACTION_DOWN
&& !createTaskText.getText().toString().equals("")) {
// setContentView(R.layout.edit_task_page);
Intent goTaskEdit = new Intent(ExpandAnimationDemo.this,
TaskEdit.class);
goTaskEdit.putExtra("Topic", createTaskText.getText()
.toString());
startActivity(goTaskEdit);
createTaskText.setText("");
}
return false;
}
};
createTaskText.setOnEditorActionListener(exListener);
// Creating list, initially = 0 list
ListView list = (ListView) findViewById(R.id.udiniList);
Task[] items = {
new Task("Task 1"),
new Task("Task 2"),
new Task("Task 3"),
new Task("Task 4"),
new Task("Task 5"),
};
// Creating the list adapter and populating the list
listAdapter = new ArrayAdapter<Task>(this,
R.layout.list_item, items);
list.setAdapter(listAdapter);
// Creating an item click listener, to open/close our toolbar for each
// item
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, final View view,
int position, long id) {
View toolbar = view.findViewById(R.id.toolbar);
// Creating the expand animation for the item
ExpandAnimation expandAni = new ExpandAnimation(toolbar, 500);
// Start the animation on the toolbar
toolbar.startAnimation(expandAni);
}
});
// !!! Set Swipe to Dismiss !!!
// Create a ListView-specific touch listener. ListViews are given special treatment because
// by default they handle touches for their list items... i.e. they're in charge of drawing
// the pressed state (the list selector), handling list item clicks, etc.
SwipeDismissListViewTouchListener touchListener =
new SwipeDismissListViewTouchListener(
list,
new SwipeDismissListViewTouchListener.DismissCallbacks() {
@Override
public boolean canDismiss(int position) {
return true;
}
@Override
public void onDismiss(ListView listView, int[] reverseSortedPositions) {
for (int position : reverseSortedPositions) {
listAdapter.remove(listAdapter.getItem(position));
}
listAdapter.notifyDataSetChanged();
}
});
list.setOnTouchListener(touchListener);
// Setting this scroll listener is required to ensure that during ListView scrolling,
// we don't look for swipes.
list.setOnScrollListener(touchListener.makeScrollListener());
}
My Task class
我的任务课
public class Task extends HistoryTask {
int priority;
Calendar duedate;
//------------------------------
// constructors
public Task() {
duedate = Calendar.getInstance();
}
public Task( String t ) {
super( t );
duedate = Calendar.getInstance();
}
public Task( String t, String d ) {
super( t, d );
duedate = Calendar.getInstance();
}
public Task( String t, String d, int tg ) {
super( t, d, tg );
duedate = Calendar.getInstance();
}
public Task( String t, String d, int tg, int p ) {
super( t, d, tg );
priority = p;
duedate = Calendar.getInstance();
}
public Task( String t, String d, int tg, int p, Calendar dd ) {
super( t, d, tg );
priority = p;
duedate = dd;
}
@Override
public String toString() {
return super.toString();
}
}
main.xml
主文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<EditText
android:id="@+id/quickTopic"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginRight="30dp"
android:layout_marginTop="10dp"
android:hint="@string/quickTaskTopic"
android:inputType="text" />
<ListView
android:id="@+id/udiniList"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="@android:color/transparent"
android:dividerHeight="10.0sp" />
</LinearLayout>
list_item.xml
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:focusable="false"
android:focusableInTouchMode="false"
android:padding="20dip" />
<ImageView
android:id="@+id/editPic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:layout_marginTop="20dp"
android:layout_toLeftOf="@+id/deletePic"
android:contentDescription="@string/EditDesc"
android:src="@drawable/pencil" />
<ImageView
android:id="@+id/deletePic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_marginRight="20dp"
android:layout_marginTop="20dp"
android:contentDescription="@string/DeleteDesc"
android:src="@drawable/delete" />
</RelativeLayout>
<!-- *********************** -->
<!-- *** TOOLBAR LAYOUT **** -->
<!-- *********************** -->
<LinearLayout
android:id="@+id/toolbar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="-20dip"
android:orientation="vertical"
android:visibility="gone" >
<!-- TextView will showing task details.The details must get from user database -->
<TextView
android:id="@+id/taskDetail"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:focusable="false"
android:focusableInTouchMode="false"
android:padding="20dp"
android:paddingLeft="50dp"
android:singleLine="false"
android:text="@string/Details" />
<!-- This RelativeLayout manage the TextView which represent the information of Priority, DueDate, and Tag s-->
<RelativeLayout
android:id="@+id/taskSpec"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:focusable="false"
android:focusableInTouchMode="false" >
<!-- TextView of "Priority" and priority value -->
<TextView
android:id="@+id/PriorityStr"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:padding="20dp"
android:paddingLeft="50dp"
android:text="@string/Priority" />
<TextView
android:id="@+id/PriorityGet"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@+id/PriorityStr"
android:padding="20dp"
android:paddingLeft="55dp"
android:text="@string/SamplePriority" />
<!-- TextView of "DueDate" and duedate value -->
<TextView
android:id="@+id/DueDateStr"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="@+id/PriorityStr"
android:padding="20dp"
android:paddingLeft="50dp"
android:text="@string/DueDate" />
<TextView
android:id="@+id/DueDateGet"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/PriorityGet"
android:layout_toRightOf="@+id/DueDateStr"
android:padding="20dp"
android:paddingLeft="50dp"
android:text="@string/SampleDueDate" />
<!-- TextView of "Tags" and tags value -->
<TextView
android:id="@+id/TagsStr"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="@+id/DueDateStr"
android:padding="20dp"
android:paddingLeft="50dp"
android:text="@string/Tags" />
<TextView
android:id="@+id/TagGet"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/DueDateGet"
android:layout_toRightOf="@+id/TagsStr"
android:padding="20dp"
android:paddingLeft="60dp"
android:text="@string/SampleTags" />
</RelativeLayout>
</LinearLayout>
</LinearLayout>
How can I solve this problem?
我怎么解决这个问题？
采纳答案by Joel Fernandes
From the error it says that ArrayAdapter requires the resource ID to be a TextView
从错误中它说 ArrayAdapter requires the resource ID to be a TextView
Try changing
尝试改变
listAdapter = new ArrayAdapter<Task>(this, R.layout.list_item, items);
to this:
对此：
listAdapter = new ArrayAdapter<Task>(this, R.layout.list_item, R.id.TEXT_VIEW_ID, items);
Replace R.id.TEXT_VIEW_IDwith the TextView id in your layout
替换R.id.TEXT_VIEW_ID为布局中的 TextView id
回答by Rahul Gupta
Array Adapter takes a xml in the second argument which should contain only a textView. You need to implement your own custom adapter because your list_itemcontains a hell lot of widgets to inflate in a ListView.
Array Adapter 在第二个参数中接受一个 xml，它应该只包含一个 textView。您需要实现自己的自定义适配器，因为您list_item包含大量要在 ListView 中膨胀的小部件。
Android's ArrayAdapter cannot do that. You need to implement your own by extending ArrayAdapter or BaseAdapter
Android 的 ArrayAdapter 无法做到这一点。您需要通过扩展 ArrayAdapter 或 BaseAdapter 来实现自己的
11-29 11:58:07.465: E/AndroidRuntime(1262): Caused by: java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.TextView
You are getting this error because your list_item parent Widget is a LinearLayout, whereas the second argument of a ArrayAdapter takes a textviewxml. For example:
您收到此错误是因为您的 list_item 父 Widget 是 a LinearLayout，而 ArrayAdapter 的第二个参数采用textviewxml。例如：
ArrayAdapter listAdapter = new ArrayAdapter(this,
android.R.layout.simple_list_item_1 items);
If you CTRL+ Clickon simple_list_item_1, a xml will open and it will look like this:
如果你CTRL+ Clickon simple_list_item_1，一个 xml 将打开，它看起来像这样：
<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2006 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceListItemSmall"
android:gravity="center_vertical"
android:paddingStart="?android:attr/listPreferredItemPaddingStart"
android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
android:minHeight="?android:attr/listPreferredItemHeightSmall"
/>
As you can see, it is a single TextView,
如你所见，它是一个单一的 TextView，
So conclusion, you need to implement your own custom adapter.
所以结论是，您需要实现自己的自定义适配器。
