android - 返回layout.getLineForOffset(selectionStart);使我的应用崩溃

Question

return layout.getLineForOffset(selectionStart);

这条线导致我的应用崩溃。

我正在用它来获取多行编辑文本中的当前光标行。像这样。

public int getCurrentCursorLine(EditText editText) {
    int selectionStart = Selection.getSelectionStart(editText.getText());
    Layout layout = editText.getLayout();

    if (!(selectionStart == -1) && editText.hasFocus()) {
        return layout.getLineForOffset(selectionStart);
    }

    return -1;
}

这是错误日志

10-18 21:07:28.711 24433-24433/com.example.tabstrial2 E/AndroidRuntime: FATAL EXCEPTION: main
                                                                    Process: com.example.tabstrial2, PID: 24433
                                                                    java.lang.NullPointerException: Attempt to invoke virtual method 'int android.text.Layout.getLineForOffset(int)' on a null object reference
                                                                        at com.example.tabstrial2.TabFragment1.getCurrentCursorLine(TabFragment1.java:451)
                                                                        at com.example.tabstrial2.TabFragment1$2.onTextChanged(TabFragment1.java:169)
                                                                        at android.widget.TextView.sendOnTextChanged(TextView.java:7689)
                                                                        at android.widget.TextView.setText(TextView.java:4070)
                                                                        at android.widget.TextView.setText(TextView.java:3925)
                                                                        at android.widget.EditText.setText(EditText.java:85)
                                                                        at android.widget.TextView.setText(TextView.java:3900)
                                                                        at android.widget.TextView.onRestoreInstanceState(TextView.java:3800)
                                                                        at android.view.View.dispatchRestoreInstanceState(View.java:13754)
                                                                        at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2894)
                                                                        at android.view.View.restoreHierarchyState(View.java:13732)
                                                                        at android.support.v4.app.Fragment.restoreViewState(Fragment.java:477)
                                                                        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1135)
                                                                        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1290)
                                                                        at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:801)
                                                                        at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1638)
                                                                        at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:679)
                                                                        at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:166)
                                                                        at android.support.v4.view.ViewPager.populate(ViewPager.java:1240)
                                                                        at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:670)
                                                                        at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:632)
                                                                        at android.support.v4.view.ViewPager.setCurrentItem(ViewPager.java:613)
                                                                        at com.example.tabstrial2.MainActivity.onNavigationItemSelected(MainActivity.java:569)
                                                                        at android.support.design.widget.NavigationView$1.onMenuItemSelected(NavigationView.java:153)
                                                                        at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:810)
                                                                        at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
                                                                        at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:957)
                                                                        at android.support.design.internal.NavigationMenuPresenter$1.onClick(NavigationMenuPresenter.java:328)
                                                                        at android.view.View.performClick(View.java:4783)
                                                                        at android.view.View$PerformClick.run(View.java:19887)
                                                                        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:5290)
                                                                        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:911)
                                                                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:706)

我也几次收到此错误，我认为这可能与与edittext View 相关的同一问题有关。

10-18 21:05:58.691 10607-24276/? E/AppsFlyer_3.0-804958145: failed to connect to t.appsflyer.com/127.0.0.1 (port 80) after 10000ms: isConnected failed: ECONNREFUSED (Connection refused)
                                                        java.net.ConnectException: failed to connect to t.appsflyer.com/127.0.0.1 (port 80) after 10000ms: isConnected failed: ECONNREFUSED (Connection refused)
                                                            at libcore.io.IoBridge.isConnected(IoBridge.java:238)
                                                            at libcore.io.IoBridge.connectErrno(IoBridge.java:171)
                                                            at libcore.io.IoBridge.connect(IoBridge.java:122)
                                                            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:183)
                                                            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:456)
                                                            at java.net.Socket.connect(Socket.java:882)
                                                            at com.android.okhttp.internal.Platform.connectSocket(Platform.java:174)
                                                            at com.android.okhttp.Connection.connect(Connection.java:152)
                                                            at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:276)
                                                            at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
                                                            at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:382)
                                                            at com.android.okhttp.internal.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:106)
                                                            at com.android.okhttp.internal.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:217)
                                                            at com.appsflyer.AppsFlyerLib.a(SourceFile:1378)
                                                            at com.appsflyer.AppsFlyerLib.b(SourceFile:1348)
                                                            at com.appsflyer.AppsFlyerLib.a(SourceFile:32)
                                                            at com.appsflyer.AppsFlyerLib$SendToServerRunnable.run(SourceFile:1534)
                                                            at com.appsflyer.AppsFlyerLib.c(SourceFile:973)
                                                            at com.appsflyer.AppsFlyerLib.a(SourceFile:32)
                                                            at com.appsflyer.AppsFlyerLib$DataCollector.run(SourceFile:1479)
                                                            at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:422)
                                                            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
                                                            at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:152)
                                                            at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:265)
                                                            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
                                                            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
                                                            at java.lang.Thread.run(Thread.java:818)
                                                         Caused by: android.system.ErrnoException: isConnected failed: ECONNREFUSED (Connection refused)
                                                            at libcore.io.IoBridge.isConnected(IoBridge.java:223)
                                                            at libcore.io.IoBridge.connectErrno(IoBridge.java:171) 
                                                            at libcore.io.IoBridge.connect(IoBridge.java:122) 
                                                            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:183) 
                                                            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:456) 
                                                            at java.net.Socket.connect(Socket.java:882) 
                                                            at com.android.okhttp.internal.Platform.connectSocket(Platform.java:174) 
                                                            at com.android.okhttp.Connection.connect(Connection.java:152) 
                                                            at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:276) 
                                                            at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211) 
                                                            at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:382) 
                                                            at com.android.okhttp.internal.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:106) 
                                                            at com.android.okhttp.internal.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:217) 
                                                            at com.appsflyer.AppsFlyerLib.a(SourceFile:1378) 
                                                            at com.appsflyer.AppsFlyerLib.b(SourceFile:1348) 
                                                            at com.appsflyer.AppsFlyerLib.a(SourceFile:32) 
                                                            at com.appsflyer.AppsFlyerLib$SendToServerRunnable.run(SourceFile:1534) 
                                                            at com.appsflyer.AppsFlyerLib.c(SourceFile:973) 
                                                            at com.appsflyer.AppsFlyerLib.a(SourceFile:32) 
                                                            at com.appsflyer.AppsFlyerLib$DataCollector.run(SourceFile:1479) 
                                                            at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:422) 
                                                            at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
                                                            at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:152) 
                                                            at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:265) 
                                                            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
                                                            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
                                                            at java.lang.Thread.run(Thread.java:818) 

也是重要信息:我的应用程序具有带有5个选项卡的tabLayout，每个选项卡包含单独的片段。当我第一次打开应用程序，并且第一次加载包含此代码的片段时，没有崩溃或错误，当我在选项卡上滑动时以及第二次返回该选项卡时，应用程序崩溃。如果这里有任何相关性，我正在使用 FragmentStatePagerAdapter。

Answer 1

我遇到了同样的问题，就我而言，似乎TextView或您的情况下EditText的布局不是由android系统完全创建的，因此getLayout()返回null。
我通过添加Handler来解决一些延迟
并在onResume()中调用上述方法

@Override
protected void onResume() {
    super.onResume();
        
    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            getCurrentCursorLine(myEditText);
        }
    }, 300); // 300 msec delay      
    
}