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Android ClassCastException on findViewById

I have a little problem when I cannot find the mistake I am making, maybe something really simple.

I have the following layout

<?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:layout_marginLeft="10dp" > <CheckBox android:id="@+id/checkBox" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:focusable="false" /> <ImageView android:id="@+id/imgStarred" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignRight="@+id/checkBox" android:layout_below="@+id/checkBox" android:layout_marginRight="4dp" android:src="@drawable/ic_star_gray"/> <CheckedTextView android:id="@+id/lblTitle" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignTop="@+id/checkBox" android:layout_marginLeft="10dp" android:layout_marginTop="8dp" android:layout_toLeftOf="@+id/imgPriority" android:layout_toRightOf="@+id/checkBox" android:text="CheckedTextView" /> <TextView android:id="@+id/lblDescription" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignRight="@+id/lblTitle" android:layout_below="@+id/lblTitle" android:layout_marginLeft="10dp" android:layout_toRightOf="@+id/checkBox" android:text="Small Text" android:textAppearance="?android:attr/textAppearanceSmall" /> <ImageView android:id="@+id/imgPriority" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_marginRight="8dp" android:layout_marginTop="8dp" android:src="@drawable/ic_priority_5" /> </RelativeLayout>

When I try to get a view from it using findViewById, I get a ClassCast exception

 11-23 10:12:07.680: E/AndroidRuntime(5965): FATAL EXCEPTION: main 11-23 10:12:07.680: E/AndroidRuntime(5965): java.lang.ClassCastException: android.widget.ImageView 11-23 10:12:07.680: E/AndroidRuntime(5965): at com.bilobait.taskbox.task.TaskBoxTaskList$TaskView.<init>(TaskBoxTaskList.java:459) 11-23 10:12:07.680: E/AndroidRuntime(5965): at com.bilobait.taskbox.task.TaskBoxTaskList$TaskBoxTaskAdapter.getView(TaskBoxTaskList.java:423) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.AbsListView.obtainView(AbsListView.java:1435) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.ListView.measureHeightOfChildren(ListView.java:1256) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.ListView.onMeasure(ListView.java:1167) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.LinearLayout.measureVertical(LinearLayout.java:386) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.LinearLayout.onMeasure(LinearLayout.java:309) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:581) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:365) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.LinearLayout.measureVertical(LinearLayout.java:531) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.LinearLayout.onMeasure(LinearLayout.java:309) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.View.measure(View.java:8313) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewRoot.performTraversals(ViewRoot.java:839) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.view.ViewRoot.handleMessage(ViewRoot.java:1862) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.os.Handler.dispatchMessage(Handler.java:99) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.os.Looper.loop(Looper.java:123) 11-23 10:12:07.680: E/AndroidRuntime(5965): at android.app.ActivityThread.main(ActivityThread.java:3695) 11-23 10:12:07.680: E/AndroidRuntime(5965): at java.lang.reflect.Method.invokeNative(Native Method) 11-23 10:12:07.680: E/AndroidRuntime(5965): at java.lang.reflect.Method.invoke(Method.java:507) 11-23 10:12:07.680: E/AndroidRuntime(5965): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842) 11-23 10:12:07.680: E/AndroidRuntime(5965): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600) 11-23 10:12:07.680: E/AndroidRuntime(5965): at dalvik.system.NativeStart.main(Native Method)

Can someone help me / give me a hint what am I missing?

thanks

EDIT: Forgot something when I pick up

 android:layout_toLeftOf="@+id/imgPriority"

from CheckedTextView the error has disappeared.

 lblTitle = (TextView)findViewById(R.id.lblTitle); lblDescription = (TextView)findViewById(R.id.lblDescription); cbCheck = (CheckBox)findViewById(R.id.checkBox); imgStar = (ImageView)findViewById(R.id.imgStarred); imgPriority = (ImageView)findViewById(R.id.imgPriority);
+6
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4 answers

Unfortunately, I did not notice at the time of my first answer that you have created identifiers in your links many times. You should not do this :). Remove all the "+" signs in all links, such as layout_toLeftOf , layout_alignRight , layout_below , etc. It will look like this:

 <?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:layout_marginLeft="10dp" > <CheckBox android:id="@+id/checkBox" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:focusable="false" /> <ImageView android:id="@+id/imgStarred" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignRight="@id/checkBox" android:layout_below="@id/checkBox" android:layout_marginRight="4dp" android:src="@drawable/ic_star_gray"/> <CheckedTextView android:id="@+id/lblTitle" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignTop="@id/checkBox" android:layout_marginLeft="10dp" android:layout_marginTop="8dp" android:layout_toLeftOf="@id/imgPriority" android:layout_toRightOf="@id/checkBox" android:text="CheckedTextView" /> <TextView android:id="@+id/lblDescription" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignRight="@id/lblTitle" android:layout_below="@id/lblTitle" android:layout_marginLeft="10dp" android:layout_toRightOf="@id/checkBox" android:text="Small Text" android:textAppearance="?android:attr/textAppearanceSmall" /> <ImageView android:id="@+id/imgPriority" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_marginRight="8dp" android:layout_marginTop="8dp" android:src="@drawable/ic_priority_5" /> </RelativeLayout>

When you write, for example, android:layout_toLeftOf="@+id/imgPriority" with a plus sign , you do , create another imgPriority identifier, and you do not referene already have the id of your ImageView.

+12
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Remove the + "sign from the android:layout_toLeftOf="@+id/imgPriority" attribute android:layout_toLeftOf="@+id/imgPriority" in the CheckedTextView annotation and add the ImageView annotation to your xml layout before id is used

+3
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define

 <ImageView android:id="@+id/imgPriority" ........... />

before

 CheckedTextView .

in relativeLayout, each view related to another must be defined after that view

0
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Check your class file, you must create an object / Find the identifier of the various controls. For example, in my case, when I took an image in an XML file and I found the identifier of an image button in a class file, this error occurred at the time.

0
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Source: https://habr.com/ru/post/902182/

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