我正在制作一個簡單的單位轉換器，當我嘗試在片段中從編輯文本中獲取值時，我的應用程序崩潰了

Question

這是我在 android 工作室制作的 UnitConveter.java 文件。

當我運行應用程序時它崩潰並且當我刪除/注釋掉edittext部分時它沒有運行它工作正常！！！

這是我發現但不知道如何修復異常的 StackTrace

2021-11-28 18:40:58.420 24299-24299/com.example.unitconveter E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.unitconveter, PID: 24299
java.lang.NumberFormatException: For input string: "androidx.appcompat.widget.AppCompatEditText{f658fcc VFED..CL. .F...... 82,294-542,416 #7f0901d2 app:id/value}"
    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
    at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
    at java.lang.Double.parseDouble(Double.java:538)
    at com.example.unitconveter.AreaConvert$1.onClick(AreaConvert.java:66)
    at android.view.View.performClick(View.java:6605)
    at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119)
    at android.view.View.performClickInternal(View.java:6582)
    at android.view.View.access$3100(View.java:778)
    at android.view.View$PerformClick.run(View.java:25897)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6692)
    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)

這是單位轉換器文件

 package com. example.Unitconverter; import android. os.Bundle; import androidx.fragment.app.Fragment; import android.text.Editable; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.Spinner; import android.widget.TextView; import android.widget.Toast; import java.util.ArrayList; public class AreaConvert extends Fragment implements AdapterView.OnItemSelectedListener{ Spinner from; Spinner to; Button convert; EditText value; TextView answer; int Value; String val; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment View v = inflater.inflate(R.layout.fragment_area_convert,container,false); from = (Spinner) v.findViewById(R.id.from); to = (Spinner) v.findViewById(R.id.to); // value = (EditText) v.findViewById(R.id.value); // val = value.getText().toString(); // I tried to get the value through tostring but didn't help // Value = Integer.parseInt(val); // convert = (Button) v.findViewById(R.id.convert); // convert.setOnClickListener(new View.OnClickListener() { // @Override // public void onClick(View view) { //// Toast.makeText(getContext(), Value, Toast.LENGTH_SHORT).show(); // } // }); //Creating an Array to populate the spinner with the data in the string resources ArrayAdapter<CharSequence> spinnerfromAdapter = ArrayAdapter.createFromResource(getContext(),R.array.areaunits, android.R.layout.simple_spinner_item); ArrayAdapter<CharSequence> spinnertoAdapter = ArrayAdapter.createFromResource(getContext(),R.array.areaunits, android.R.layout.simple_spinner_item); spinnerfromAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); spinnertoAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); from.setAdapter(spinnerfromAdapter); from.setOnItemSelectedListener(this); to.setAdapter(spinnertoAdapter); to.setOnItemSelectedListener(this); return v; } @Override public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) { String text = adapterView.getItemAtPosition(i).toString(); Toast.makeText(adapterView.getContext(), text, Toast.LENGTH_SHORT).show(); // switch(view.getId()){ // case R.id.from: // String program = String.valueOf(from.getSelectedItem()); // switch(program){ // case "": // default: // break; // } // break; // case R.id.to: // // break; // default: //// throw new IllegalStateException("Unexpected value: " + view.getId()); // break; // } } @Override public void onNothingSelected(AdapterView<?> adapterView) { } }

這是我的 XML 文件

 <?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/frameLayout" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".AreaConvert"> <Spinner android:id="@+id/from" android:layout_width="259dp" android:layout_height="55dp" android:gravity="center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="1.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.146" /> <TextView android:id="@+id/textView" android:layout_width="93dp" android:layout_height="47dp" android:text="FROM" android:textAlignment="center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toStartOf="@+id/from" app:layout_constraintHorizontal_bias="1.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.168" /> <TextView android:id="@+id/textView2" android:layout_width="98dp" android:layout_height="54dp" android:layout_marginStart="4dp" android:text="TO" android:textAlignment="center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toStartOf="@+id/to" app:layout_constraintHorizontal_bias="1.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.375" /> <Spinner android:id="@+id/to" android:layout_width="259dp" android:layout_height="55dp" android:gravity="center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="1.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.343" /> <EditText android:id="@+id/value" android:layout_width="336dp" android:layout_height="40dp" android:ems="10" android:inputType="numberDecimal" app:layout_constraintBottom_toTopOf="@+id/to" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/from" android:autofillHints="" /> <TextView android:id="@+id/answer" android:layout_width="204dp" android:layout_height="43dp" android:text="TextView" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.516" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/to" app:layout_constraintVertical_bias="0.109" /> <Button android:id="@+id/convert" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="244dp" android:text="CONVERT" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.498" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/answer" app:layout_constraintVertical_bias="0.707" /> </androidx.constraintlayout.widget.ConstraintLayout>

我想使用編輯文本中的值來找到答案

你也能給我建議最好的 android 開發視頻/課程（免費）謝謝你的幫助

Answer 1

首先，您必須學習一些命名約定。

其次， StackTrace 對於您顯示的代碼並不實際。 在AreaConvert.java第 66 行的某個地方，必須是一個 onClick 監聽器，它可以轉換一些value .toDouble() 。 StackTrace 錯誤告訴您該value無法轉換為 double