Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()'

 

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
        at android.content.ComponentName.<init>(ComponentName.java:130)
        at android.content.Intent.<init>(Intent.java:5819)
        at android.view.View.performClick(View.java:6291)
        at android.view.View$PerformClick.run(View.java:24931)
        at android.os.Handler.handleCallback(Handler.java:808)
        at android.os.Handler.dispatchMessage(Handler.java:101)
        at android.os.Looper.loop(Looper.java:166)
        at android.app.ActivityThread.main(ActivityThread.java:7529)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)

 

出現這個錯誤，是由於用Intent啓動Activity時候，傳遞給Intent的第一個參數爲空，即：

new Intent(_mActivity, xxxActivity.class)

中，_mActivity爲空