Unable to add window -- token android.os.BinderProxy@xxx is not valid; is your activity running

android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@47ddb860 is not valid; is your activity running?
	at android.view.ViewRootImpl.setView(ViewRootImpl.java:594)
	at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:269)
	at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
	at android.app.Dialog.show(Dialog.java:323)
	at cn.beeba.app.activity.ChannelActivity.q(ChannelActivity.java:1034)
	at cn.beeba.app.activity.ChannelActivity.b(ChannelActivity.java:686)
	at cn.beeba.app.activity.ChannelActivity.b(ChannelActivity.java:662)
	at cn.beeba.app.activity.ChannelActivity$2.handleMessage(ChannelActivity.java:377)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loop(Looper.java:136)
	at android.app.ActivityThread.main(ActivityThread.java:5315)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:515)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680)

at dalvik.system.NativeStart.main(Native Method)

解决方法：

if(!((Activity) context).isFinishing())
{
    //show dialog
}