应用程序意外停止

时间：2012-03-01 19:11:47

标签： android button android-intent android-listview

当我运行我的Android应用程序时出现错误＆＃34;应用程序已停止工作，请再试一次＆＃34;。请帮我解决这个问题。我创建了一个方法，当单击按钮时调用该方法。当我在此方法中包含用于调用另一个类的代码时，它会显示上述错误＆amp;当我删除该代码时，它既不显示错误也不会在listview等被点击时继续。你可以检查我的代码并帮助我。

CODE：

public void myClickHandler(View view)
    {
        //Toast.makeText(this, "yesss",Toast.LENGTH_LONG).show();
         setContentView(R.layout.screen1);
         ListAdapter adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, city);
         ListView FirstProjectActivity = (ListView) findViewById(R.id.mylist1);
         FirstProjectActivity.setAdapter(adapter);

         Intent myIntent = new Intent(FirstProjectActivity.this,
                 City.class);
        FirstProjectActivity.this.startActivity(myIntent);

         //startActivity(new Intent(FirstProjectActivity.this, City.class));
    }

LOGCAT如下：

  03-02 18:56:28.136: D/AndroidRuntime(316): Shutting down VM
03-02 18:56:28.136: W/dalvikvm(316): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-02 18:56:28.226: E/AndroidRuntime(316): FATAL EXCEPTION: main
03-02 18:56:28.226: E/AndroidRuntime(316): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.FirstProject/com.example.FirstProject.FirstProjectActivity}: java.lang.NullPointerException
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.os.Looper.loop(Looper.java:123)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-02 18:56:28.226: E/AndroidRuntime(316):  at java.lang.reflect.Method.invokeNative(Native Method)
03-02 18:56:28.226: E/AndroidRuntime(316):  at java.lang.reflect.Method.invoke(Method.java:521)
03-02 18:56:28.226: E/AndroidRuntime(316):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-02 18:56:28.226: E/AndroidRuntime(316):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-02 18:56:28.226: E/AndroidRuntime(316):  at dalvik.system.NativeStart.main(Native Method)
03-02 18:56:28.226: E/AndroidRuntime(316): Caused by: java.lang.NullPointerException
03-02 18:56:28.226: E/AndroidRuntime(316):  at com.example.FirstProject.FirstProjectActivity.onCreate(FirstProjectActivity.java:37)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-02 18:56:28.226: E/AndroidRuntime(316):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
03-02 18:56:28.226: E/AndroidRuntime(316):  ... 11 more
03-02 18:56:35.396: I/Process(316): Sending signal. PID: 316 SIG: 9
03-02 19:02:51.836: D/AndroidRuntime(351): Shutting down VM
03-02 19:02:51.836: W/dalvikvm(351): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-02 19:02:51.866: E/AndroidRuntime(351): FATAL EXCEPTION: main
03-02 19:02:51.866: E/AndroidRuntime(351): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.FirstProject/com.example.FirstProject.FirstProjectActivity}: java.lang.NullPointerException
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.os.Looper.loop(Looper.java:123)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-02 19:02:51.866: E/AndroidRuntime(351):  at java.lang.reflect.Method.invokeNative(Native Method)
03-02 19:02:51.866: E/AndroidRuntime(351):  at java.lang.reflect.Method.invoke(Method.java:521)
03-02 19:02:51.866: E/AndroidRuntime(351):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-02 19:02:51.866: E/AndroidRuntime(351):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-02 19:02:51.866: E/AndroidRuntime(351):  at dalvik.system.NativeStart.main(Native Method)
03-02 19:02:51.866: E/AndroidRuntime(351): Caused by: java.lang.NullPointerException
03-02 19:02:51.866: E/AndroidRuntime(351):  at com.example.FirstProject.FirstProjectActivity.onCreate(FirstProjectActivity.java:37)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-02 19:02:51.866: E/AndroidRuntime(351):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
03-02 19:02:51.866: E/AndroidRuntime(351):  ... 11 more
03-02 19:03:03.647: I/Process(351): Sending signal. PID: 351 SIG: 9
03-02 20:11:17.722: W/KeyCharacterMap(379): No keyboard for id 0
03-02 20:11:17.926: W/KeyCharacterMap(379): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
03-02 20:11:28.441: D/dalvikvm(379): GC_EXPLICIT freed 3121 objects / 172672 bytes in 1696ms
03-03 01:03:02.696: W/KeyCharacterMap(406): No keyboard for id 0
03-03 01:03:02.696: W/KeyCharacterMap(406): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
03-03 01:03:08.566: D/dalvikvm(406): GC_EXPLICIT freed 2874 objects / 162408 bytes in 192ms
03-03 01:33:06.566: D/AndroidRuntime(432): Shutting down VM
03-03 01:33:06.566: W/dalvikvm(432): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:33:06.726: E/AndroidRuntime(432): FATAL EXCEPTION: main
03-03 01:33:06.726: E/AndroidRuntime(432): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.view.View$1.onClick(View.java:2072)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.view.View.performClick(View.java:2408)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.view.View$PerformClick.run(View.java:8816)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.os.Looper.loop(Looper.java:123)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:33:06.726: E/AndroidRuntime(432):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:33:06.726: E/AndroidRuntime(432):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:33:06.726: E/AndroidRuntime(432):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:33:06.726: E/AndroidRuntime(432):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:33:06.726: E/AndroidRuntime(432):  at dalvik.system.NativeStart.main(Native Method)
03-03 01:33:06.726: E/AndroidRuntime(432): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:33:06.726: E/AndroidRuntime(432):  at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:69)
03-03 01:33:06.726: E/AndroidRuntime(432):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:33:06.726: E/AndroidRuntime(432):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.view.View$1.onClick(View.java:2067)
03-03 01:33:06.726: E/AndroidRuntime(432):  ... 11 more
03-03 01:33:06.726: E/AndroidRuntime(432): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:33:06.726: E/AndroidRuntime(432):  at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:33:06.726: E/AndroidRuntime(432):  ... 15 more
03-03 01:33:08.956: I/Process(432): Sending signal. PID: 432 SIG: 9
03-03 01:34:05.387: D/AndroidRuntime(460): Shutting down VM
03-03 01:34:05.387: W/dalvikvm(460): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:34:05.417: E/AndroidRuntime(460): FATAL EXCEPTION: main
03-03 01:34:05.417: E/AndroidRuntime(460): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.view.View$1.onClick(View.java:2072)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.view.View.performClick(View.java:2408)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.view.View$PerformClick.run(View.java:8816)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.os.Looper.loop(Looper.java:123)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:34:05.417: E/AndroidRuntime(460):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:34:05.417: E/AndroidRuntime(460):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:34:05.417: E/AndroidRuntime(460):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:34:05.417: E/AndroidRuntime(460):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:34:05.417: E/AndroidRuntime(460):  at dalvik.system.NativeStart.main(Native Method)
03-03 01:34:05.417: E/AndroidRuntime(460): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:34:05.417: E/AndroidRuntime(460):  at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:70)
03-03 01:34:05.417: E/AndroidRuntime(460):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:34:05.417: E/AndroidRuntime(460):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.view.View$1.onClick(View.java:2067)
03-03 01:34:05.417: E/AndroidRuntime(460):  ... 11 more
03-03 01:34:05.417: E/AndroidRuntime(460): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:34:05.417: E/AndroidRuntime(460):  at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:34:05.417: E/AndroidRuntime(460):  ... 15 more
03-03 01:34:11.016: I/Process(460): Sending signal. PID: 460 SIG: 9
03-03 01:35:33.547: D/AndroidRuntime(490): Shutting down VM
03-03 01:35:33.557: W/dalvikvm(490): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:35:33.577: E/AndroidRuntime(490): FATAL EXCEPTION: main
03-03 01:35:33.577: E/AndroidRuntime(490): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.view.View$1.onClick(View.java:2072)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.view.View.performClick(View.java:2408)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.view.View$PerformClick.run(View.java:8816)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.os.Looper.loop(Looper.java:123)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:35:33.577: E/AndroidRuntime(490):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:35:33.577: E/AndroidRuntime(490):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:35:33.577: E/AndroidRuntime(490):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:35:33.577: E/AndroidRuntime(490):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:35:33.577: E/AndroidRuntime(490):  at dalvik.system.NativeStart.main(Native Method)
03-03 01:35:33.577: E/AndroidRuntime(490): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:35:33.577: E/AndroidRuntime(490):  at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:70)
03-03 01:35:33.577: E/AndroidRuntime(490):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:35:33.577: E/AndroidRuntime(490):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.view.View$1.onClick(View.java:2067)
03-03 01:35:33.577: E/AndroidRuntime(490):  ... 11 more
03-03 01:35:33.577: E/AndroidRuntime(490): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:35:33.577: E/AndroidRuntime(490):  at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:35:33.577: E/AndroidRuntime(490):  ... 15 more
03-03 01:35:39.176: I/Process(490): Sending signal. PID: 490 SIG: 9
03-03 01:36:06.947: D/AndroidRuntime(517): Shutting down VM
03-03 01:36:06.947: W/dalvikvm(517): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:36:06.967: E/AndroidRuntime(517): FATAL EXCEPTION: main
03-03 01:36:06.967: E/AndroidRuntime(517): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.view.View$1.onClick(View.java:2072)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.view.View.performClick(View.java:2408)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.view.View$PerformClick.run(View.java:8816)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.os.Looper.loop(Looper.java:123)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:36:06.967: E/AndroidRuntime(517):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:36:06.967: E/AndroidRuntime(517):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:36:06.967: E/AndroidRuntime(517):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:36:06.967: E/AndroidRuntime(517):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:36:06.967: E/AndroidRuntime(517):  at dalvik.system.NativeStart.main(Native Method)
03-03 01:36:06.967: E/AndroidRuntime(517): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:36:06.967: E/AndroidRuntime(517):  at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:70)
03-03 01:36:06.967: E/AndroidRuntime(517):  at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:36:06.967: E/AndroidRuntime(517):  at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.view.View$1.onClick(View.java:2067)
03-03 01:36:06.967: E/AndroidRuntime(517):  ... 11 more
03-03 01:36:06.967: E/AndroidRuntime(517): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:36:06.967: E/AndroidRuntime(517):  at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:36:06.967: E/AndroidRuntime(517):  ... 15 more
03-03 01:36:13.306: I/Process(517): Sending signal. PID: 517 SIG: 9

2 个答案:

答案 0 :(得分：0)

如果你想检测你是否点击了一个需要实现onItemClickedListener的项目，我会给你一个例子，就像我会这样做：

listView.setOnItemClickListener(new MyOnitemClickListener());
//no i make my own class that impelemnts the onitemclicklistener
public class MyOnitemClickListener implements OnItemClickListener {
        private int position = 0;

        public void onItemClick(AdapterView<?> parent, View view, int pos,
                long lat) {
             // clicked on parent.getid()
             if (parent.getId() == R.id.listView) {
            //do something
         } 

    }
}

答案 1 :(得分：0)

在崩溃之后，尝试寻找LOGCAT向你喷出的前几条红线，因为它们通常会解释发生了什么。

以下一行：

  

显示java.lang.NullPointerException

（第5行）显示在您的日志上，通常表示您尝试使用未初始化的对象。

参考：

What is a NullPointerException, and how do I fix it?

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