Why do I get token null is not valid error in Android?

Question

I hope to open a dialog box, the Code A works well. In order to make the code universally, I place the function promptBuyWhenExpired into Utility.kt, then I invoke the function in onCreate() just like Code B, but I get the following error information, what wrong do I make ?

Error Information

   java.lang.RuntimeException: Unable to start activity ComponentInfo{info.dodata.mirror/ui.UIMain}: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
        at android.os.Handler.dispatchMessage(Handler.java:105)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6541)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
     Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
        at android.view.ViewRootImpl.setView(ViewRootImpl.java:765)
        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:356)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:92)
        at android.app.Dialog.show(Dialog.java:330)
        at utility.UtilityKt.promptBuyWhenExpired(Utility.kt:106)
        at ui.UIMain.onCreate(UIMain.kt:70)
        at android.app.Activity.performCreate(Activity.java:6975)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)

Code A

class UIMain : AppCompatActivity() { 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.layout_main)

        promptBuyWhenExpired()

    }

    private fun promptBuyWhenExpired() {
        if (IsExpired(applicationContext) ) {
            val builder = AlertDialog.Builder(this)
            builder.setMessage(getString(R.string.ExpiredTitle))
            builder.setTitle(getString(R.string.ExpiredWarning))
            builder.setCancelable(false)
            builder.setPositiveButton(getString(R.string.BtnYes)) { dialog, which ->
                finish()
            }
            builder.create().show()
        }
    }
}

Code B

class UIMain : AppCompatActivity() { 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.layout_main)

        Utility.promptBuyWhenExpired(this)
    }

}




Utility.kt
public fun promptBuyWhenExpired(mActivity: Activity) {
    var mContent= mActivity.applicationContext
    if (IsExpired(mContent) ) {
        val builder = AlertDialog.Builder(mContent)
        builder.setMessage(mContent.getString(R.string.ExpiredTitle))
        builder.setTitle(mContent.getString(R.string.ExpiredWarning))
        builder.setCancelable(false)
        builder.setPositiveButton(mContent.getString(R.string.BtnYes)) { dialog, which ->
            mActivity.finish()
        }
        builder.create().show()
    }
}

Modified in Code B

The following code can work, but I don't know if the code can work well in all mobile phone.

//promptBuyWhenExpired(this@UImain) is Ok
//promptBuyWhenExpired(this) is Ok too.
public fun promptBuyWhenExpired(mActivity: Activity) {
    var mContent= mActivity.applicationContext
    if (IsExpired(mContent) ) {
        val builder = AlertDialog.Builder(mActivity)  //The paramter is mActivity
        builder.setMessage(mContent.getString(R.string.ExpiredTitle))
        builder.setTitle(mContent.getString(R.string.ExpiredWarning))
        builder.setCancelable(false)
        builder.setPositiveButton(mContent.getString(R.string.BtnYes)) { dialog, which ->
            mActivity.finish()
        }
        builder.create().show()
    }
}

Possible duplicate of [PopupWindow $BadTokenException: Unable to add window -- token null is not valid](https://stackoverflow.com/questions/8782250/popupwindow-badtokenexception-unable-to-add-window-token-null-is-not-valid) — Shaishav, May 07 '18 at 09:05
replace mContent with mActivity in AlertDialog.Builder(mContent) — steevoo, May 07 '18 at 09:06
check for `if (!isFinishing && !isDestroyed)` for your `activity` inside your `promptBuyWhenExpired()`. — Kasim Rangwala, May 07 '18 at 10:54
In Utility: `val builder = AlertDialog.Builder(mContent)` here you are using application context not activity context. — RobCo, May 07 '18 at 11:41

IntelliJ Amiya · Accepted Answer · 2018-05-07T12:19:31.910

2

Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?

Read This Expression .

DO

This Step for Code B

 Utility.promptBuyWhenExpired(this@UIMain)

Then

public fun promptBuyWhenExpired(mActivity: Activity) {
       if (IsExpired(mActivity) ) {

You should pass this@CurrentActivityName instead of this.

NOTE

builder.setPositiveButton(mContent.getString(R.string.BtnYes)) { dialog, which ->

            val handler = Handler()
            handler.postDelayed({  mActivity.finish() }, 300)
        }

edited May 07 '18 at 12:19

answered May 07 '18 at 09:07

IntelliJ Amiya

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Thanks! but I still the same error when I use Utility.promptBuyWhenExpired(this@UIMain) – HelloCW May 07 '18 at 09:25
Are there some problem with the function public fun promptBuyWhenExpired(mActivity: Activity) {...} in Code B ? – HelloCW May 07 '18 at 09:26
Is `var mContent= mActivity.applicationContext` right in my Code B? – HelloCW May 07 '18 at 09:26
@HelloCW comment `var mContent= mActivity.applicationContext` – IntelliJ Amiya May 07 '18 at 09:27
@HelloCW use `val builder = AlertDialog.Builder(this@UIMain)` – IntelliJ Amiya May 07 '18 at 09:30
1

Thanks! 'mActivity.finish()' will cause error by your code because `public fun promptBuyWhenExpired(mActivity: Context) {...}` in Code B – HelloCW May 07 '18 at 09:41
@HelloCW add `dialog.dismiss()` before `mActivity.finish()` – IntelliJ Amiya May 07 '18 at 09:44
I hope to close UImain instead of dialog – HelloCW May 07 '18 at 09:45
and more ,you can't invoke `mActivity.finish()` because mActivity is Context by your code `public fun promptBuyWhenExpired(mActivity: Context)...` – HelloCW May 07 '18 at 09:48
A Context havn't finish() function – HelloCW May 07 '18 at 09:49
@HelloCW good. For test case comment `mActivity.finish()` and let me inform – IntelliJ Amiya May 07 '18 at 09:53
Thanks! but I need to invoke finish() to close UIMain – HelloCW May 07 '18 at 11:24
@HelloCW Add 300 ms delay time to avoid exception – IntelliJ Amiya May 07 '18 at 11:39
Thanks! Would you please see my modified question? My modified code can work, but I don't know if the code can work well in all mobile phone. – HelloCW May 08 '18 at 00:15
In modified code, I can pass parameter either `this` or `this@UIMain`, why? Thanks! – HelloCW May 08 '18 at 00:24
@HelloCW Have a look here https://stackoverflow.com/questions/7933206/android-unable-to-add-window-token-null-is-not-for-an-application-exception – IntelliJ Amiya May 08 '18 at 05:13

Why do I get token null is not valid error in Android?

1 Answers1