我理解这是一个非常长篇大论的请求，希望任何人都能回答，但我已经尝试了一些我能想到的解决这个问题的方法。
在我的Android应用程序中，我首先进行此活动，该活动接受用户输入（数字）并将其传递给下一个活动：
public class Practice extends Activity implements View.OnClickListener {
// Declaring Vars
Button go2;
EditText enterNumber2;
TextView top2;
TextView bottom2;
private Integer convertedNumber2; // change back to private Integer?
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setting equal to text layout View
setContentView(R.layout.practice);
// calling method to intialise vars
initialiseVars();
// setting on click listeners for edit text and button
go2.setOnClickListener(this);
enterNumber2.setOnClickListener(this);
}// on create end
/**
* method to initialise all of the buttons, textviews etc used to clean up
* the onCreate.
*/
private void initialiseVars() {
// Setting up (initialising) all the buttons text views etc from the xml
// (vid 25)
go2 = (Button) findViewById(R.id.btnGoPractice);
enterNumber2 = (EditText) findViewById(R.id.etEnterNumberPractce);
top2 = (TextView) findViewById(R.id.tvTopPractice);
bottom2 = (TextView) findViewById(R.id.tvBottomPractice);
}
/**
* Method with on click listener that adds functionality for all of the
* buttons, text views etc
*
* @param v
*/
public void onClick(View view) {
// switch statement which determines what is clicked
switch ((view).getId()) {
case R.id.btnGoPractice:
// sets text view equal to whats typed in in editText
final String entry = enterNumber2.getText().toString().trim();// get your number
entry.replaceAll("\\D+","");//possibly delete
try {
convertedNumber2 = Integer.parseInt(entry);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
Intent intent = new Intent(this, PracticeTest.class);
if (convertedNumber2 >= 1 && convertedNumber2 <= 12) {
intent.putExtra("convertedNumber2", convertedNumber2);
System.out.println("Valid number");
} else {
System.out.println("Invalid number");
}
startActivity(intent);
/**
* UNCOMMENT THIS IF THE ABOVE DOESNT WORK
// sets text view equal to whats typed in in editText final
* String entry = enterNumber2.getText().toString();
*
* // convert from string value to int convertedNumber2 =
* Integer.parseInt(entry);
*
* Intent intent = new Intent(this, PracticeTest.class); if
* (convertedNumber2 >= 1 && convertedNumber2 <= 12) {
* intent.putExtra("convertedNumber2", convertedNumber2);
* startActivity(intent); } else {
* System.out.println("Invalid number"); }
*
* break; default: System.out.println("invalid entry"); break;
*
* }
*/
}
}
}// c end
以下活动收到数字，并根据数字（乘法时间表）开始循环问题：
public class PracticeTest extends Activity implements View.OnClickListener {
// declare vars
int multiplier;
int[] results = new int[12];
int numberPassed;
TextView question;
EditText answer;
int score;
String[] questions = new String[12];
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.practicetest);
// This declares and int variable, assigns it an int value from the
// calling Intent if its not there it is defaulted to 0
numberPassed = getIntent().getIntExtra("convertedNumber2", 0);
// setting up vars(possibly do this in different method?
Button submit = (Button) findViewById(R.id.btnGoPractice2);
answer = (EditText) findViewById(R.id.etEnterNumberPractice2);
question = (TextView) findViewById(R.id.tvTopPractice2);
// setting listeners
submit.setOnClickListener(this);
updateQuestion();
}
public void onClick(View view) {
// sets text view equal to whats typed in in editText
final String entry = answer.getText().toString();
// convert from string value to int
int a = Integer.parseInt(entry); // note: maybe change name
results[multiplier - 1] = a;
score++;// Irrelevant?
if (multiplier < 12) {
// called after an answer is given
updateQuestion();
} else {
// System.out.println(score);
Intent intent = new Intent(this, Results.class);
intent.putExtra("results", results);
intent.putExtra("numberPassed", numberPassed);
intent.putExtra("questions", questions);
this.startActivity(intent);
}
}
public void updateQuestion() {
multiplier++;
// string to hold quest
String q = numberPassed + "x" + multiplier + "=";
questions[multiplier - 1] = q;
question.setText(questions[multiplier - 1]);
answer.setText("");
}
}
然后，此活动会获取用户的答案等，并将其传递给此活动：
public class Results extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.results);
ListView itemList = (ListView) findViewById(R.id.lvresults);
//gets arrays from prev act
int[] results = getIntent().getIntArrayExtra("results");
int numberPassed = getIntent().getIntExtra("numberPassed", 0);
String[] questions= getIntent().getStringArrayExtra("questions");
ArrayList < HashMap <String, String> > list = new ArrayList < HashMap <String, String> > ();
// loop to give list view
for (int i = 1; i <= 12; i++)
{
int userAnswer = results[i - 1];
int expectedAnswer = numberPassed * i;
String userString = numberPassed + " x " + i + " = " + userAnswer;
String expectedString = " " + expectedAnswer;
HashMap <String, String> map = new HashMap <String, String> ();
map.put("user", userString);
map.put("expected", expectedString);
list.add(map);
}
// Instantiate custom array adapter
MyArrayAdapterPractice adapter = new MyArrayAdapterPractice(this.getApplicationContext(), R.layout.list_row_practice, list, questions, results);
// Here you set the custom adapter to your ListView.
itemList.setAdapter(adapter);
}
}
在整个过程中，我使用以下适配器：
public class MyArrayAdapterPractice extends ArrayAdapter<ArrayList<HashMap<String, String>>>
{
Context mContext;
ArrayList<HashMap<String, String>> mQuestionArrayList;
int mLayoutResourceId;
String[] mQuestionsArray;
int[] mUsersAnswers;
public MyArrayAdapterPractice(Context context, int layoutResourceId, ArrayList<HashMap<String, String>> questionsArrayList, String[] questionsArray, int[] usersAnswers)
{
super(context, layoutResourceId);
mContext = context;
this.mQuestionArrayList = questionsArrayList;
this.mLayoutResourceId = layoutResourceId;
this.mQuestionsArray = questionsArray;
this.mUsersAnswers = usersAnswers;
}
@Override
public int getCount()
{
return mQuestionArrayList.size();
}
@Override
public View getView(int position, View row, ViewGroup parent)
{
HashMap<String, String> question = mQuestionArrayList.get(position);
LayoutInflater inflater = LayoutInflater.from(mContext);
// Here you will initialize the row layout, by inflating the xml file list_row.
row = inflater.inflate(this.mLayoutResourceId, parent, false);
// Here we initialize those two TextViews defined in the list_row layout.
TextView questionTxtView = (TextView) row.findViewById(R.id.tvPracticeQuestion);
TextView answerTxtView = (TextView) row.findViewById(R.id.tvPracticeAnswer);
TextView correctAnswerTxtView = (TextView) row.findViewById(R.id.tvPracticeCorrect);
questionTxtView.setText(mQuestionsArray[position]);
answerTxtView.setText(String.valueOf(mUsersAnswers[position]));
correctAnswerTxtView.setText(question.get("expected").toString());
// This is just a pseudo code to show you when and how to set the colors of
// the TextView programatically.
if(mUsersAnswers[position] != Integer.parseInt(question.get("expected").toString()))
answerTxtView.setTextColor(Color.RED);
else
answerTxtView.setTextColor(Color.GREEN);
return row;
}
}
最后这是我尝试运行代码时得到的logcat错误跟踪（请注意，仿真器会在result.java活动即将打开的情况下切断）：
04-28 19:03:54.792: E/AndroidRuntime(1059): FATAL EXCEPTION: main
04-28 19:03:54.792: E/AndroidRuntime(1059): Process: com.example.multapply, PID: 1059
04-28 19:03:54.792: E/AndroidRuntime(1059): java.lang.NumberFormatException: Invalid int: " 9"
04-28 19:03:54.792: E/AndroidRuntime(1059): at java.lang.Integer.invalidInt(Integer.java:137)
04-28 19:03:54.792: E/AndroidRuntime(1059): at java.lang.Integer.parse(Integer.java:374)
04-28 19:03:54.792: E/AndroidRuntime(1059): at java.lang.Integer.parseInt(Integer.java:365)
04-28 19:03:54.792: E/AndroidRuntime(1059): at java.lang.Integer.parseInt(Integer.java:331)
04-28 19:03:54.792: E/AndroidRuntime(1059): at com.example.multapply.MyArrayAdapterPractice.getView(MyArrayAdapterPractice.java:59)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.AbsListView.obtainView(AbsListView.java:2263)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.ListView.measureHeightOfChildren(ListView.java:1263)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.ListView.onMeasure(ListView.java:1175)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.View.measure(View.java:16497)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.View.measure(View.java:16497)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.View.measure(View.java:16497)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
04-28 19:03:54.792: E/AndroidRuntime(1059): at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.View.measure(View.java:16497)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
04-28 19:03:54.792: E/AndroidRuntime(1059): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2291)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.View.measure(View.java:16497)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1916)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1113)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1295)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.Choreographer.doCallbacks(Choreographer.java:574)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.Choreographer.doFrame(Choreographer.java:544)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.os.Handler.handleCallback(Handler.java:733)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.os.Handler.dispatchMessage(Handler.java:95)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.os.Looper.loop(Looper.java:136)
04-28 19:03:54.792: E/AndroidRuntime(1059): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-28 19:03:54.792: E/AndroidRuntime(1059): at java.lang.reflect.Method.invokeNative(Native Method)
04-28 19:03:54.792: E/AndroidRuntime(1059): at java.lang.reflect.Method.invoke(Method.java:515)
04-28 19:03:54.792: E/AndroidRuntime(1059): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-28 19:03:54.792: E/AndroidRuntime(1059): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-28 19:03:54.792: E/AndroidRuntime(1059): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：2)
要找出错误所在，您必须读取堆栈跟踪。这是相关部分（强调我的）：
04-28 19：03：54.792：E / AndroidRuntime（1059）： java.lang.NumberFormatException：无效的int：＆＃34; 9＆＃34;
04-28 19：03：54.792：E / AndroidRuntime（1059）：at java.lang.Integer.invalidInt（Integer.java:137）
04-28 19：03：54.792：E / AndroidRuntime（1059）：at java.lang.Integer.parse（Integer.java:374）
04-28 19：03：54.792：E / AndroidRuntime（1059）：at java.lang.Integer.parseInt（Integer.java:365）
04-28 19：03：54.792：E / AndroidRuntime（1059）：at java.lang.Integer.parseInt（Integer.java:331）
04-28 19：03：54.792：E / AndroidRuntime（1059）： at com.example.multapply.MyArrayAdapterPractice.getView（MyArrayAdapterPractice.java:59）
因此，这意味着在方法MyArrayAdapterPractice#getView内的文件 MyArrayAdapterPractice.java 的第59行引发了错误。您只需要转到当前代码的那一部分，检查问题并修复它。
从分析中，错误消息非常具体：
java.lang.NumberFormatException: Invalid int: " 9"
您正在发送" 9"，但无法将其转换为Integer。修剪字符串，然后解析它。
这是有问题的一行：
if(mUsersAnswers[position] != Integer.parseInt(question.get("expected").toString()))
将其转换为
if(mUsersAnswers[position] != Integer.parseInt(question.get("expected").toString().trim()))