Android.widget,textView cannot be cast to android.

2019-01-16 19:17发布

I keep getting a runtime error when launching my activity and it says android.widget.textview cannot be cast to android.widget.button?

XML:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:ignore="HardcodedText" >

    <TextView
        android:id="@+id/textViewName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="false"
        android:layout_alignParentTop="false"
        android:text="Name:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewLevel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/textViewName"
        android:text="Level:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewClass"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="false"
        android:layout_below="@+id/textViewLevel"
        android:text="Class:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textViewClass"
        android:layout_alignBottom="@+id/textViewClass"
        android:layout_centerHorizontal="true"
        android:text="Title:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewXP"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textViewTitle"
        android:layout_alignLeft="@+id/textViewTitle"
        android:text="XP:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewGold"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textViewXP"
        android:layout_alignParentTop="true"
        android:text="Gold:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewLineBreak"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textViewClass"
        android:text="________________________________________"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:visibility="invisible" />

    <TextView
        android:id="@+id/textViewGoldValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_toRightOf="@+id/textViewGold"
        android:text="0"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_toLeftOf="@+id/textViewTitle"
        android:text="Stats" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/button3"
        android:layout_alignParentLeft="true"
        android:layout_marginBottom="20dp"
        android:layout_toLeftOf="@+id/textViewTitle"
        android:text="Equipment" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/button2"
        android:layout_alignParentLeft="true"
        android:layout_alignRight="@+id/button2"
        android:layout_marginBottom="22dp"
        android:text="Inventory" />

    <Button
        android:id="@+id/Button01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button1"
        android:layout_alignBottom="@+id/button1"
        android:layout_alignLeft="@+id/button4"
        android:layout_alignParentRight="true"
        android:text="Shop" />

    <Button
        android:id="@+id/button5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/button2"
        android:layout_toRightOf="@+id/textViewXP"
        android:text="Class Training" />

    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button5"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/button1"
        android:text="Crafting" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textViewLineBreak"
        android:text="HP:"
        android:textAppearance="?android:attr/textAppearanceMedium" />


    <TextView
        android:id="@+id/textViewStrTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textViewLineBreak"
        android:layout_alignLeft="@+id/textViewGoldValue"
        android:text="N/A"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <TextView
        android:id="@+id/textViewXPValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textViewGoldValue"
        android:layout_below="@+id/textViewGoldValue"
        android:text="0"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewLevelValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textViewClass"
        android:layout_toRightOf="@+id/textViewName"
        android:text="1"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/TextViewStrClass"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textViewLineBreak"
        android:layout_alignLeft="@+id/textViewLevelValue"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <TextView
        android:id="@+id/textViewRace"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textViewClass"
        android:text="Race:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView4"
        android:layout_alignBottom="@+id/textView4"
        android:layout_toLeftOf="@+id/TextViewStrClass"
        android:text="10"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <Spinner
        android:id="@+id/spinnerMonsters"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView4"
        android:layout_marginTop="50dp"
        android:layout_toLeftOf="@+id/btnBattle"
        android:entries="@array/Monsters"
        android:prompt="@string/MonsterPrompt" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/spinnerMonsters"
        android:layout_alignRight="@+id/textViewXPValue"
        android:text="10"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <Button
        android:id="@+id/btnBattle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignTop="@+id/spinnerMonsters"
        android:text="Battle!" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textViewStrTitle"
        android:layout_alignRight="@+id/spinnerMonsters"
        android:layout_marginRight="14dp"
        android:text="/"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewXpNextLevel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textViewLevel"
        android:layout_alignBottom="@+id/textViewLevel"
        android:layout_alignLeft="@+id/btnBattle"
        android:text="100"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textViewBattleResults"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/spinnerMonsters"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <TextView
        android:id="@+id/textViewStrRace"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textView1"
        android:layout_toRightOf="@+id/textViewClass"
        android:text="l"
        android:textAppearance="?android:attr/textAppearanceSmall" />


    <TextView
        android:id="@+id/textViewStrAlliance"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/textView2"
        android:layout_alignParentRight="true"
        android:layout_toRightOf="@+id/textViewStrTitle"
        android:text="Small Text"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <TextView
        android:id="@+id/textViewAlliance"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textViewTitle"
        android:layout_toRightOf="@+id/button1"
        android:text="Alliance:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textView6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textViewAlliance"
        android:layout_below="@+id/textViewLineBreak"
        android:text="MP:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

What is happening here? I've gone through it a few times and can't find anything

Edit:

09-17 18:28:51.485: E/AndroidRuntime(724): FATAL EXCEPTION: main
09-17 18:28:51.485: E/AndroidRuntime(724): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.intent_buttontests/com.example.intent_buttontests.PlayScreen}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.os.Handler.dispatchMessage(Handler.java:99)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.os.Looper.loop(Looper.java:137)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.ActivityThread.main(ActivityThread.java:4424)
09-17 18:28:51.485: E/AndroidRuntime(724):  at java.lang.reflect.Method.invokeNative(Native Method)
09-17 18:28:51.485: E/AndroidRuntime(724):  at java.lang.reflect.Method.invoke(Method.java:511)
09-17 18:28:51.485: E/AndroidRuntime(724):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
09-17 18:28:51.485: E/AndroidRuntime(724):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
09-17 18:28:51.485: E/AndroidRuntime(724):  at dalvik.system.NativeStart.main(Native Method)
09-17 18:28:51.485: E/AndroidRuntime(724): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
09-17 18:28:51.485: E/AndroidRuntime(724):  at com.example.intent_buttontests.PlayScreen.onCreate(PlayScreen.java:110)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.Activity.performCreate(Activity.java:4465)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
09-17 18:28:51.485: E/AndroidRuntime(724):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
09-17 18:28:51.485: E/AndroidRuntime(724):  ... 11 more

10条回答
Viruses.
2楼-- · 2019-01-16 19:40

you are trying to cast TextView to Button.

for TextView do this :

TextView tv = (TextView)findviewById(R.id.your textviewid present in xml layout file);

for Button :

Button btn1 = (Button)findviewById(R.id.your buttonid present in xml layout file);
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走好不送
3楼-- · 2019-01-16 19:47

I added the logcat. But i have no idea what is happening

This is the important information in your LogCat file:

Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
  at com.example.intent_buttontests.PlayScreen.onCreate(PlayScreen.java:110)

You read the error correctly, it is a ClassCastException. The lines below Caused by... tell you where the error was thrown, which is in PlayScreen.onCreate() on line 110. As best I can tell line 110 is:

Button btnBattle = (Button) findViewById(R.id.btnBattle);

But this line is fine and the XML for btnBattle looks fine too...

I ran your Activity with your layout myself and didn't get any errors. Have you cleaned your project? Often this will remove these "phantom" errors. (In Eclipse, Project -> Clean...)


I do have one suggestion, you have a lot of Buttons that do similar tasks. You can do the same actions with much less code if you use the XML onClick attribute. First create a method (call it launchClick()) in your Activity like so:

public void launchClick(View v) {
    Intent intent;

    switch(v.getId()) {
    case R.id.button1:
        intent = new Intent(PlayScreen.this, Inventory.class);
        break;

    case R.id.button2:
        intent = new Intent(PlayScreen.this, Equipment.class);
        break;

    // etc, etc
    }
    startActivityForResult(intent, 0);
};

And add the attribute android:onClick to every Button that you should have this behavior in play_screen.xml:

<Button
    android:id="@+id/button3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_toLeftOf="@+id/textViewTitle"
    android:onClick="launchClick"
    android:text="Stats" />

Hope that helps!

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倾城 Initia
4楼-- · 2019-01-16 19:47
  1. Project > Clean

Or

  1. change itemes Id's

it help :D

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叛逆
5楼-- · 2019-01-16 19:50

Project -> Clean can help you.

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手持菜刀,她持情操
6楼-- · 2019-01-16 19:50

In case the project clean does not work. The cause might be related to use te same ID on more than one item.

Make sure when assigning ID´s via layout or programatically, that are not duplicated.

I faced this issue while assinging low numbers as ID (probably not a best practice), as the ID's where colliding with RadioButton checked ID.

Cheers

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一夜七次
7楼-- · 2019-01-16 19:57

I just encountered the same problem. However, i decided to use only "View" without casting. It works perfectly. "setOnClickListener" works the same for our case.

e.g. View button = v.findViewById(button_id); button.setOnClickListener(...)

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