我正在制作一个测验应用,我正在使用一个EditText
,当我没有输入任何内容时,按SubmitButton
我会收到此错误:
FATAL EXCEPTION: main
Process: com.example.andriod.quiz, PID: 12960
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293) at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19761)
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:5264)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19761)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5264)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)
Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.content.res.Resources.getText(Resources.java:284)
at android.widget.TextView.setText(TextView.java:4176)
at com.example.andriod.quiz.MainActivity.submitAnswer(MainActivity.java:65)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19761)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5264)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)
这是我的java代码:
package com.example.andriod.quiz;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.RadioButton;
import android.widget.TextView;
import android.widget.Toast;
/**
* This app displays Millionaire Quiz
*/
public class MainActivity extends AppCompatActivity {
private String name;
private int correctAnswers;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/**
* This method is called when the Ok button is clicked. it's displays personalized greetings.
*
* @param view
*/
public void greetings(View view) {
EditText nameField = (EditText) findViewById(R.id.customer_name);
name = nameField.getText().toString();
TextView greetings = (TextView) findViewById(R.id.greetings);
greetings.setText("Hello " + name + ". Scroll down if you are ready.");
InputMethodManager inputManager = (InputMethodManager)
getSystemService(Context.INPUT_METHOD_SERVICE);
inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(),
InputMethodManager.HIDE_NOT_ALWAYS);
LinearLayout questionsLayout = (LinearLayout) findViewById(R.id.questions_layout);
questionsLayout.setVisibility(View.VISIBLE);
}
/**
* Checks correct answers, and displays a toast with congratulations and amount of correctly answered questions.
*
* @param view
*/
public void submitAnswer(View view) {
correctAnswers = 0;
RadioButton firstQuestion = (RadioButton) findViewById(R.id.first_correct);
if (firstQuestion.isChecked()) {
correctAnswers++;
}
EditText secondQuestion = (EditText) findViewById(R.id.second_question);
int answer = Integer.parseInt(secondQuestion.getText().toString());
if (answer == 27) {
correctAnswers++;
}
CheckBox checkBoxA = (CheckBox) findViewById(R.id.answer_a);
CheckBox checkBoxB = (CheckBox) findViewById(R.id.answer_b);
CheckBox checkBoxC = (CheckBox) findViewById(R.id.answer_c);
CheckBox checkBoxD = (CheckBox) findViewById(R.id.answer_d);
if (!checkBoxA.isChecked() && checkBoxB.isChecked() && checkBoxC.isChecked() && !checkBoxD.isChecked()) {
correctAnswers++;
}
RadioButton fourthQuestion = (RadioButton) findViewById(R.id.fourth_correct);
if (fourthQuestion.isChecked()) {
correctAnswers++;
}
RadioButton fifthQuestion = (RadioButton) findViewById(R.id.fifth_correct);
if (fifthQuestion.isChecked()) {
correctAnswers++;
}
String correctlyAnswered;
switch (correctAnswers) {
case 5:
correctlyAnswered = "Congratulation " + name + " you answer correctly to every question! You won 1 million! ";
break;
case 4:
correctlyAnswered = "Congratulation " + name + " you answer correctly to 4 questions! You won 750 thousands! You should try one more time!";
break;
case 3:
correctlyAnswered = "Congratulation " + name + " you answer correctly to 3 questions! You won 500 thousands! You should try one more time!";
break;
case 2:
correctlyAnswered = "Congratulation " + name + " you answer correctly to 3 questions! You won 250 thousands! You should try one more time!";
break;
case 1:
correctlyAnswered = "Congratulation " + name + " you answer correctly to 1 question! You won 100 thousands! You should try one more time!";
break;
default:
correctlyAnswered = "You didn't answer correctly to any question :( \nYou should try one more time!";
}
Toast toast = Toast.makeText(this, correctlyAnswered, Toast.LENGTH_LONG);
toast.show();
}
}
这是xml文件:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/second_activity"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#6158AC"
android:orientation="vertical"
tools:context="com.example.andriod.quiz.MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="16dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="16dp"
android:text="Welcome in Millionaire Game! \nAre you ready to play for a million?"
android:textSize="24sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:id="@+id/customer_name"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="Name"
android:inputType="textCapWords" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="greetings"
android:text="Ok"
android:textAllCaps="true" />
</LinearLayout>
<TextView
android:id="@+id/greetings"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="16dp"
android:paddingTop="16dp"
android:textSize="24sp" />
<LinearLayout
android:id="@+id/questions_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:visibility="visible">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="First question: \nHow many parts has Harry Potter series?" />
<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RadioButton
android:id="@+id/first_correct"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Seven" /><!--correct-->
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Eight" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Six" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Three" />
</RadioGroup>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Second question: \nOwen thinks of a number, adds 13, and then divides the result by 5. The answer is 8. Find the number Owen thinks of." />
<EditText
android:id="@+id/second_question"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:inputType="number"
android:hint="Write here your answer." />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Third question: \nWhat is a value of absolute zero?" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<CheckBox
android:id="@+id/answer_a"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-189°C" />
<CheckBox
android:id="@+id/answer_b"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-271,15°C" /><!--correct-->
<CheckBox
android:id="@+id/answer_c"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="0K" /><!--correct-->
<CheckBox
android:id="@+id/answer_d"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="100K" />
</LinearLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Fourth question: \nWhat is the main component in glass?" />
<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RadioButton
android:id="@+id/fourth_correct"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sand" /> <!--correct-->
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Iron" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Coal" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Water" />
</RadioGroup>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Fifth question: \nWhich is the largest species of the tiger?" />
<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Chinese tiger" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Bengali tiger" />
<RadioButton
android:id="@+id/fifth_correct"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Siberian tiger" /><!--correct-->
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Indo-Chinese tiger" />
</RadioGroup>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="submitAnswer"
android:text="Submit answers"
android:textAllCaps="true" />
</LinearLayout>
</LinearLayout>
有谁知道为什么会出现这种错误? 我为我犯的每一个错误感到抱歉,这是我的第一个问题;)
答案 0 :(得分:0)
它在这里失败了:
int answer = Integer.parseInt(secondQuestion.getText().toString());
此处必须有一个非空字段,并且它也应该是一个数字。
您只需检查:
int answer = 0;
EditText secondQuestion = (EditText) findViewById(R.id.second_question);
if(secondQuestion.getText().toString().equals("")) {
//Handle invalid input
} else {
answer = Integer.parseInt(secondQuestion.getText().toString());
}
只需对无效输入进行一些验证,这可以轻松处理。