Question

我正在使用eclipse开发一个Android应用程序。每次我在AVD中运行它都会出现错误“不幸已停止”。我试图使用Android动画在启动活动和主菜单活动之间转换。以下是支持主要活动的java代码的一部分：

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.start_up);
    startAnimating();
}
private void startAnimating() {
    // TODO Auto-generated method stub
    TextView logo1 = (TextView) findViewById(R.id.title);
    Animation fade1 = AnimationUtils.loadAnimation(this, R.animator.fade_in);
    logo1.startAnimation(fade1);
    TextView logo2 = (TextView) findViewById(R.id.secondTV);
    Animation fade2 = AnimationUtils.loadAnimation(this, R.animator.fade_in2);
    logo2.startAnimation(fade2);

    fade2.setAnimationListener(new AnimationListener(){

        @Override
        public void onAnimationEnd(Animation animation) {
            // TODO Auto-generated method stub
            startActivity(new Intent(Startup.this, SymptomViewer.class));
            Startup.this.finish();

        }

        @Override
        public void onAnimationRepeat(Animation animation) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onAnimationStart(Animation animation) {
            // TODO Auto-generated method stub

        }

    });


    }
protected void onPause(){
    super.onPause();
    TextView logo1 = (TextView) findViewById(R.id.title);
    logo1.clearAnimation();
    TextView logo2 = (TextView) findViewById(R.id.secondTV);
    logo2.clearAnimation();

}
protected void onResume(){
    super.onResume();
    startAnimating();
}
}

我一直在互联网上的论坛上搜索，我似乎无法解决这个问题。但是我检查了logcat，我发现了与Null指针异常有关的事情，这在引用时会涉及到。我已经多次运行我的代码，看起来很好。可能导致这种情况的原因。

这是LogCat

05-06 18:24:58.925: D/AndroidRuntime(1355): Shutting down VM
05-06 18:24:58.925: W/dalvikvm(1355): threadid=1: thread exiting with uncaught exception (group=0xb2a98ba8)
05-06 18:24:58.965: E/AndroidRuntime(1355): FATAL EXCEPTION: main
05-06 18:24:58.965: E/AndroidRuntime(1355): Process: com.example.ubumitrial1, PID: 1355
05-06 18:24:58.965: E/AndroidRuntime(1355): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ubumitrial1/com.example.ubumitrial1.Startup}: java.lang.NullPointerException
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.os.Handler.dispatchMessage(Handler.java:102)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.os.Looper.loop(Looper.java:136)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread.main(ActivityThread.java:5017)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at java.lang.reflect.Method.invokeNative(Native Method)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at java.lang.reflect.Method.invoke(Method.java:515)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at dalvik.system.NativeStart.main(Native Method)
05-06 18:24:58.965: E/AndroidRuntime(1355): Caused by: java.lang.NullPointerException
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.example.ubumitrial1.Startup.startAnimating(Startup.java:27)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.example.ubumitrial1.Startup.onCreate(Startup.java:17)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.Activity.performCreate(Activity.java:5231)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-06 18:24:58.965: E/AndroidRuntime(1355):     ... 11 more
05-06 18:25:02.275: I/Process(1355): Sending signal. PID: 1355 SIG: 9

Answer 1

05-06 18:24:58.965: E/AndroidRuntime(1355): Caused by: java.lang.NullPointerException
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.example.ubumitrial1.Startup.startAnimating(Startup.java:27)

这些日志行显示NPE发生在第27行。转到该行（双击＆＃34; at＆＃34; Eclipse中的行跳转到代码）

这可能是一行：widget.doSomething()。由于widget为null（之前通过findViewById初始化可能失败，您必须修复布局[或代码]中的ID），因此抛出NPE。

Answer 2

FATAL EXCEPTION: main
05-06 18:24:58.965: E/AndroidRuntime(1355): Process: com.example.ubumitrial1, PID: 1355
05-06 18:24:58.965: E/AndroidRuntime(1355): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ubumitrial1/com.example.ubumitrial1.Startup}: java.lang.NullPointerException
05-06 18:24:58.965: E/AndroidRuntime(1355):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)

根据此错误消息，我感觉您可能没有在Manifest文件中正确声明此活动。你有正确的定义吗？请仔细检查声明

    Caused by: java.lang.NullPointerException
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.example.ubumitrial1.Startup.startAnimating(Startup.java:27)
05-06 18:24:58.965: E/AndroidRuntime(1355):     at com.example.ubumitrial1.Startup.onCreate(Startup.java:17)

根据此消息，您指的是未正确初始化的组件。请检查第17和27行。这些都有助于解决您的问题。

如果无法解决问题，请随意张贴突出显示行号的代码以及清单文件。

Answer 3

我得到了ubuntu 14.04 LTS的解决方案转到终端类型＆＃34; android AVD＆＃34;然后等到模拟器启动。现在去eclipse运行你的android项目并强制项目运行抛出在线模拟器（仍在运行）。希望对你有效。干杯！

＆＃34;不幸的是（应用程序名称）已停止＆＃34;在Android模拟器中

3 个答案: