Question

进一步冒险进入Android Studio！

我确实有这个工作。我有一个登录活动，然后传递到另一个。现在非常简单。完美地在模拟器上工作。尝试连接我的手机并且它抛出了一个NetworkOnMainException ...所以，研究了这个并将互联网登录检查到一个单独的异步线程中。

当我现在执行我的应用程序时，当它启动新活动时，它会崩溃。奇怪的是，如果我调试它并逐步执行代码，它就可以工作，并显示第二个活动。如果我让应用程序按照自己的速度运行，它就会崩溃。

我的登录按钮方法是：

public void signInButtonClick(View v) throws InterruptedException {

       // Button button=(Button) v;

        String loginSql;

        Globals.userName =   loginID.getText().toString();

        Globals.passWord = loginPW.getText().toString();
        //www.myarraydata.com/app/androidlogin.php?username=X&password=Y
        loginSql = "http://www.mywebsite.com/app/loginscript.php?username="+Globals.userName+"&password="+Globals.passWord ;
        ((Button) v).setText("Signing in...");
        System.out.println(loginSql);
        //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        try {
            url = new URL(loginSql);

            new loginTask().execute();

            System.out.println(readStream);

        if(readStream.equals("FAIL"))
            {
                loggedIn = false;
            }
            else
            {
                loggedIn = true;
                //Store the list of arrays for this customer in the arrayList global variable
                Globals.arrayList = Arrays.asList(readStream.split("\\s*#\\s*"));

            }

        } catch (Exception e) {
            System.out.println(e);
            e.printStackTrace();
        }



    if (loggedIn==true)
    {

        startActivity(new Intent(MainActivity.this,LiveStatus.class));
        Thread.sleep(1000);
        finish();
    }
        else
    {
        new AlertDialog.Builder(this)
                .setTitle("Oops...")
                .setMessage("Sign in failed. Please try again.")
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // continue with delete
                    }
                })
                .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        System.exit(0);
                    }
                })
                .setIcon(android.R.drawable.ic_dialog_alert)
                .show();
    }

Logcat显示它是由signInButtonClick中的InvocationTargetExcecption和NullPointerException引起的。

10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime: FATAL EXCEPTION: main
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime: java.lang.IllegalStateException: Could not execute method of the activity
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$1.onClick(View.java:2072)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View.performClick(View.java:2408)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:8816)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:587)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:92)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4627)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:  Caused by: java.lang.reflect.InvocationTargetException
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at app.ictis.com.myarraydaya.MainActivity.signInButtonClick(MainActivity.java:133)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$1.onClick(View.java:2067)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View.performClick(View.java:2408) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:8816) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:587) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:92) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4627) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:  Caused by: java.lang.NullPointerException
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at app.ictis.com.myarraydaya.MainActivity.signInButtonClick(MainActivity.java:133) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$1.onClick(View.java:2067) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View.performClick(View.java:2408) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:8816) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:587) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:92) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4627) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)

有什么想法吗？

Answer 1

发现当我声明时，loggedIn变量需要分配。那是空指针。我

new loginTask().execute();

在正常模式下，

似乎没有正确执行，只有在设置时才会执行......这是奇怪的。

指向弗兰克指针（没有双关语！）

Android Studio新活动导致崩溃

1 个答案: