报错：java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView

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 小编在调用View的时候出错。。。

 错误代码：

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageResource(int)' on a null object reference
                                                                                        at com.example.administrator.exercise.ToastActivity.onClick(ToastActivity.java:51)
                                                                                        at android.view.View.performClick(View.java:4780)
                                                                                        at android.view.View$PerformClick.run(View.java:19866)
                                                                                        at android.os.Handler.handleCallback(Handler.java:739)
                                                                                        at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                        at android.os.Looper.loop(Looper.java:135)
                                                                                        at android.app.ActivityThread.main(ActivityThread.java:5293)
                                                                                        at java.lang.reflect.Method.invoke(Native Method)
                                                                                        at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

错误原因

画圈的地方忘了写！！！也就是没通过view1就给图片连接了。。。。难怪空呢—  。 —