问题描述
我的应用程序的一项功能允许用户仅输入Edittext即可更新其锻炼的元素。 在后台，我使用@H_502_1@TextWatcher来监听更改并将每个更改保存到打开UI时弹出的mutableList中。 当mutableList包含1个以上的元素时，它可以正常工作。但是当只有一个元素时，它将返回错误。
我如何使用MutableList是否存在问题？
我将数据输入到此处的数组列表中
@H_502_1@dialogviewmodel.clickedExercise(this,exerciseID) {repList = it.numberOfReps.split(",") as MutableList<String> ...}
然后，我为每个元素创建一个Edittext。
@H_502_1@ editTextReps.apply { setText(reps) //textAlignment = View.TEXT_ALIGNMENT_CENTER textSize = 20f id = repInt setBackgroundColor(WHITE) setPadding(0,16,0) layoutParams = ViewGroup.LayoutParams( ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT )...}
然后我听每个EditText中的更改
@H_502[email protected](object : TextWatcher { override fun afterTextChanged(p0: Editable?) { exercise.numberOfReps = repString.toString() if (repTrial == repString.toString()) Log.d(TAG,"nothing Change") else Log.d(TAG,"It changed") dialogviewmodel.update(exercise) Log.d(TAG,repString.toString()) repString.clear() } override fun beforeTextChanged(p0: CharSequence?,p1: Int,p2: Int,p3: Int) { } override fun onTextChanged( exerciseString: CharSequence?,p3: Int ) { //repList[listPosition] //Todo: Position probably not right,error occurs when attempt is made to modify single set Log.d(TAG,"${repList.size},${repList[listPosition]},\n$repTrial") val testString = exerciseString.toString() Log.d(TAG,"test: $testString") this is the issue -> -> -> ->repList[listPosition] = testString Log.d(TAG,"List Position: $listPosition,${repList[listPosition]}") for (rep in repList) { repString.append("$rep,") Log.d(TAG,"${repList.size}") } } })
此代码可以在多个项目上正常工作，但是在MutableList仅包含一个项目时会崩溃
错误读取
@H_502_1@E/InputEventReceiver: Exception dispatching input event. E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback E/MessageQueue-JNI: java.lang.UnsupportedOperationException at java.util.AbstractList.add(AbstractList.java:148) at com.homeofficeprojects.countmyreps.DialogUpdateExercise$onCreate$1$5.onTextChanged(DialogUpdateExercise.kt:195) at android.widget.TextView.sendOnTextChanged(TextView.java:9754) at android.widget.TextView.handleTextChanged(TextView.java:9851) at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:12509) at android.text.SpannableStringBuilder.sendTextChanged(SpannableStringBuilder.java:1263) at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:575) at android.text.SpannableStringBuilder.delete(SpannableStringBuilder.java:229) at android.text.SpannableStringBuilder.delete(SpannableStringBuilder.java:36) at android.text.method.BaseKeyListener.backspaceOrForwardDelete(BaseKeyListener.java:370) at android.text.method.BaseKeyListener.backspace(BaseKeyListener.java:71) at android.text.method.BaseKeyListener.onKeyDown(BaseKeyListener.java:479) at android.text.method.QwertyKeyListener.onKeyDown(QwertyKeyListener.java:362) at android.text.method.TextKeyListener.onKeyDown(TextKeyListener.java:141) at android.widget.TextView.doKeyDown(TextView.java:7665) at android.widget.TextView.onKeyDown(TextView.java:7442) at android.view.KeyEvent.dispatch(KeyEvent.java:2692) at android.view.View.dispatchKeyEvent(View.java:12450) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.widget.ScrollView.dispatchKeyEvent(ScrollView.java:389) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at com.android.internal.policy.DecorView.superdispatchKeyEvent(DecorView.java:428) at com.android.internal.policy.PhoneWindow.superdispatchKeyEvent(PhoneWindow.java:1820) at android.app.Dialog.dispatchKeyEvent(Dialog.java:811) at com.android.internal.policy.DecorView.dispatchKeyEvent(DecorView.java:342) at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:5037) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4905) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4585) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4642) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4585) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4642) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$InputStage. D/AndroidRuntime: Shutting down VM E/AndroidRuntime: FATAL EXCEPTION: main Process: com.homeofficeprojects.countmyreps,PID: 10507 java.lang.UnsupportedOperationException at java.util.AbstractList.add(AbstractList.java:148) at com.homeofficeprojects.countmyreps.DialogUpdateExercise$onCreate$1$5.onTextChanged(DialogUpdateExercise.kt:195) at android.widget.TextView.sendOnTextChanged(TextView.java:9754) at android.widget.TextView.handleTextChanged(TextView.java:9851) at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:12509) at android.text.SpannableStringBuilder.sendTextChanged(SpannableStringBuilder.java:1263) at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:575) at android.text.SpannableStringBuilder.delete(SpannableStringBuilder.java:229) at android.text.SpannableStringBuilder.delete(SpannableStringBuilder.java:36) at android.text.method.BaseKeyListener.backspaceOrForwardDelete(BaseKeyListener.java:370) at android.text.method.BaseKeyListener.backspace(BaseKeyListener.java:71) at android.text.method.BaseKeyListener.onKeyDown(BaseKeyListener.java:479) at android.text.method.QwertyKeyListener.onKeyDown(QwertyKeyListener.java:362) at android.text.method.TextKeyListener.onKeyDown(TextKeyListener.java:141) at android.widget.TextView.doKeyDown(TextView.java:7665) at android.widget.TextView.onKeyDown(TextView.java:7442) at android.view.KeyEvent.dispatch(KeyEvent.java:2692) at android.view.View.dispatchKeyEvent(View.java:12450) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.widget.ScrollView.dispatchKeyEvent(ScrollView.java:389) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1896) at com.android.internal.policy.DecorView.superdispatchKeyEvent(DecorView.java:428) at com.android.internal.policy.PhoneWindow.superdispatchKeyEvent(PhoneWindow.java:1820) at android.app.Dialog.dispatchKeyEvent(Dialog.java:811) at com.android.internal.policy.DecorView.dispatchKeyEvent(DecorView.java:342) at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:5037) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4905) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4585) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4642) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4585) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4642) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) E/AndroidRuntime: at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4479) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4445) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4585) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4453) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4642) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4426) at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:7092) at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:7061) at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:7022) at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:7195) at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:186) at android.os.MessageQueue.nativePollOnce(Native Method) at android.os.MessageQueue.next(MessageQueue.java:326) at android.os.Looper.loop(Looper.java:160) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
解决方法
关于split(delimiter)方法-如果delimiter没有出现在输入中的任何地方，则结果列表只有一个元素包含原始输入。因此，在这种情况下，输出列表是不可变的（SingletonList），并且不支持add操作（它会抛出UnsupportedOperationException）。
要获取可变列表，可以使用toMutableList()方法：
repList = it.numberOfReps.split(",").toMutableList()