我正在尝试运行此代码，但我在堆栈跟踪中将其视为错误 [重复]答案

【问题标题】：I'm trying to run this code but I'm getting this as an error in Stack trace [duplicate]我正在尝试运行此代码，但我在堆栈跟踪中将其视为错误 [重复]
【发布时间】：2021-07-13 04:35:30
【问题描述】：

我正在尝试运行一段代码，但在运行我的程序时显示以下堆栈跟踪：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.mytrial, PID: 8868
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mytrial/com.example.mytrial.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.example.mytrial.MainActivity.onCreate(MainActivity.java:19)
        at android.app.Activity.performCreate(Activity.java:8000)
        at android.app.Activity.performCreate(Activity.java:7984)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7656) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

我不知道为什么会这样。

【问题讨论】：

标签： java android-studio debugging

【解决方案1】：

根据日志，java.lang.NullPointerException 在“尝试在空对象引用上调用虚拟方法 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)'”时发生

请查看您是否可以在您的代码中找到 TextView 小部件及其侦听器。

如果这有帮助，请告诉我们。

【讨论】：