BadTokenException (Similar to race condition)：未校验登录 View 导致的应用崩溃

[liyansong2018]

[scenario]
点击“点击头像登录”，此时并不登录；点击“看帖”，出发崩溃

[Analysis]
将要弹出的 dialog（登录）所要依附的 View 已经不存在导致的。

//Ruisi-master/app/src/main/java/me/yluo/ruisiapp/activity/LoginActivity.java
@Override
public void onFailure(Throwable e) {
	AlertDialog dialog = new AlertDialog.Builder(LoginActivity.this)
			.setTitle("加载失败")
			.setMessage("是否重新加载")
			.setPositiveButton("重新加载", (dialogInterface, i) -> loadData())
			.setNegativeButton("关闭", (dialogInterface, i) -> finish())
			.create();
	dialog.show();
}

[Suggestions]

if(!isFinishing()){
	dialog.show();
}

[Log]

beyond1q:/data/system/dropbox # cat [email protected]
Process: me.yluo.ruisiapp
Flags: 0x28c8be44
Package: me.yluo.ruisiapp v40 (2.9.8.2)
Foreground: Yes
Build: samsung/dream2qltezh/dream2qltechn:7.1/N2G48H/G9550ZHU1AQEE:user/release-keys

android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@e6abc7e is not valid; is your activity running?
        at android.view.ViewRootImpl.setView(ViewRootImpl.java:679)
        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:342)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:93)
        at android.app.Dialog.show(Dialog.java:329)
        at me.yluo.ruisiapp.activity.LoginActivity$4.onFailure(LoginActivity.java:212)
        at me.yluo.ruisiapp.myhttp.ResponseHandler.handleMessage(ResponseHandler.java:60)
        at me.yluo.ruisiapp.myhttp.ResponseHandler.access$000(ResponseHandler.java:13)
        at me.yluo.ruisiapp.myhttp.ResponseHandler$ResponderHandler.handleMessage(ResponseHandler.java:151)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6198)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:891)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:781)