如果我理解你的问题,我认为这就是你想要添加的内容,因为当你从活动返回时,将被称为“onResume”:-
@Override
protected void onResume() {
super.onResume();
String[] selectionArgs = {String.valueOf(globalVariable.getQuestion_number())};
c = myDbHelper.query(table, columns, selection, selectionArgs, groupBy, having, orderBy);
if (c.moveToFirst()) {
do {
question_no.setText(c.getString(0));
ques_text.setText(c.getString(1));
option1.setText(c.getString(2));
option2.setText(c.getString(3));
option3.setText(c.getString(4));
option4.setText(c.getString(5));
answer_text = c.getString(6);
Toast.makeText(activityQuiz.this,
"_id: " + c.getString(0) + "\n"+
"_answer" + c.getString(6),
Toast.LENGTH_LONG).show();
} while (c.moveToNext());
}
}
把这个从里面移开
onRestart
可能在重新启动时放弃
) :-
final Global globalVariable = (Global) getApplicationContext();
e、 g.:-
public class activityQuiz extends AppCompatActivity {
private RadioGroup radioGroup;
private RadioButton radioButton,option1,option2,option3,option4;
private Button submitBtn;
private String answer_text;
private TextView question_no,ques_text;
final Global globalVariable = (Global) getApplicationContext();
....... rest of the code .....
尽管创建一个获取数据并将其分配给视图的特定方法可能有意义,但可以从
onCreate
onResume
只有一行。
我认为您遇到的问题是,正如我所评论的,变量不是持久的。因此,我建议合并另一个问题进度表。
这个新表基本上是相关问题的链接(下面的代码假设,如果存在链接行,则问题已得到回答)。它有3列_id、问题的链接/引用(包含问题_id)和状态列(未使用但可用于指示状态,例如已回答但不正确)。
在保存有问题的数据库时,我这样做是为了让MainActivity始终尝试创建
进步
我没有参加过其他活动。然而
submitQuestion
首先是我使用的布局,即。
,所有这些都包括标题的文本视图和问题的文本视图(将显示
抱歉,还没有准备好问题
当没有问题时)4个文本视图,带有答案复选框(我这样做是为了使问题不需要4个选项,但4是最大值),最后是一个提交按钮。
活动_main。xml:-
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="mjt.so46111824.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Questions" />
<TextView
android:id="@+id/question"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/answer1_text"
android:layout_width="0dp"
android:layout_weight="10"
android:layout_height="match_parent" />
<CheckBox
android:id="@+id/answer1_checkbox"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/answer2_text"
android:layout_width="0dp"
android:layout_weight="10"
android:layout_height="match_parent" />
<CheckBox
android:id="@+id/answer2_checkbox"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/answer3_text"
android:layout_width="0dp"
android:layout_weight="10"
android:layout_height="match_parent" />
<CheckBox
android:id="@+id/answer3_checkbox"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/answer4_text"
android:layout_width="0dp"
android:layout_weight="10"
android:layout_height="match_parent" />
<CheckBox
android:id="@+id/answer4_checkbox"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent" />
</LinearLayout>
<Button
android:id="@+id/submit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="SUBMIT"/>
</LinearLayout>
DBHelper。java:-
class DBHelper extends SQLiteOpenHelper {
public static final String DBNAME = "questions";
public static final String TABLENAME = "questions";
public static final String IDCOLUMN = "_id";
public static final String QUESTIONCOLUMN = "question";
public static final String NUMBERCOLUMN = "number";
public static final String ANSWER1COLUMN = "answer1";
public static final String ANSWER2COLUMN = "answer2";
public static final String ANSWER3COLUMN = "answer3";
public static final String ANSWER4COLUMN = "answer4";
public static final String CORRECTCOLUMN = "correctanswer";
public static final String PROGRESSTABLENAME = "progress";
public static final String QUESTIONREFCOLUMN = "questionref";
public static final String QUESTIONSTATECOLUMN = "questionstate";
String crtsql;
DBHelper(Context context) {
super(context, DBNAME, null, 1);
this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
crtsql = "CREATE TABLE IF NOT EXISTS " + TABLENAME + "(" +
IDCOLUMN + " INTEGER PRIMARY KEY, " +
QUESTIONCOLUMN + " TEXT, " +
NUMBERCOLUMN + " INTEGER, " +
ANSWER1COLUMN + " TEXT, " +
ANSWER2COLUMN + " TEXT, " +
ANSWER3COLUMN + " TEXT, " +
ANSWER4COLUMN + " TEXT, " +
CORRECTCOLUMN + " INTEGER " +
")";
db.execSQL(crtsql);
createProgresstable(db);
}
public void createProgresstable(SQLiteDatabase db) {
String crtsql = "CREATE TABLE IF NOT EXISTS " + PROGRESSTABLENAME + "(" +
IDCOLUMN + " INTEGER PRIMARY KEY, " +
QUESTIONREFCOLUMN + " INTEGER NOT NULL," +
QUESTIONSTATECOLUMN + "INTEGER DEFAULT 0" +
")";
db.execSQL(crtsql);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
public void insertQuestion(String question,
int number,
String answer1,
String answer2,
String answer3,
String answer4,
int correctanswer) {
if (correctanswer < 1 || correctanswer > 4) {
Log.d("QUESTIONS","Invalid Question - Correct Answer outside of range 1-4.");
return;
}
ContentValues cv = new ContentValues();
cv.put(QUESTIONCOLUMN,question);
cv.put(NUMBERCOLUMN,number);
cv.put(ANSWER1COLUMN,answer1);
cv.put(ANSWER2COLUMN,answer2);
cv.put(ANSWER3COLUMN,answer3);
cv.put(ANSWER4COLUMN,answer4);
cv.put(CORRECTCOLUMN,correctanswer);
this.getWritableDatabase().insert(TABLENAME,null,cv);
}
public int getRowCount() {
Cursor csr = this.getWritableDatabase().query(TABLENAME,null,null,null,null,null,null);
int rv = csr.getCount();
csr.close();
return rv;
}
public Cursor getQuestionRow(long questionid) {
String whereclause = IDCOLUMN + "=?";
String[] whereargs = {Long.toString(questionid)};
return this.getWritableDatabase().query(TABLENAME,
null,
whereclause,whereargs,
null,null,null);
}
public void insertProgress(Long questionid) {
ContentValues cv = new ContentValues();
cv.put(QUESTIONREFCOLUMN,questionid);
this.getWritableDatabase().insert(PROGRESSTABLENAME,null,cv);
}
public Cursor getProgressOfQuestion(long questionid) {
String whereclause = QUESTIONREFCOLUMN + "=?";
String[] whereargs = {Long.toString(questionid)};
return this.getWritableDatabase().query(PROGRESSTABLENAME,null,whereclause,whereargs,null,null,null
);
}
public void updateProgressStatus(long questionid,int newstatus) {
String whereclause = QUESTIONREFCOLUMN + "=?";
String[] wherargs = {Long.toString(questionid)};
ContentValues cv = new ContentValues();
cv.put(QUESTIONSTATECOLUMN,newstatus);
this.getWritableDatabase().update(PROGRESSTABLENAME,
cv,
whereclause,
wherargs
);
}
public long getNextQuestionID() {
//SELECT * FROM questions LEFT JOIN progress ON questions._id = progress.questionref WHERE progress._id IS NULL ORDER BY questions.number ASC
long rv = 0;
SQLiteDatabase db = this.getWritableDatabase();
String whereclause = PROGRESSTABLENAME + "." + IDCOLUMN + " IS NULL ";
String[] whereargs = null;
Cursor csr = db.query(TABLENAME +
" LEFT JOIN " + PROGRESSTABLENAME +
" ON " + TABLENAME + "." + IDCOLUMN + " = " +
PROGRESSTABLENAME + "." + QUESTIONREFCOLUMN,
null,
whereclause,
whereargs,
null,null,
TABLENAME + "." + NUMBERCOLUMN + " ASC");
if (csr.moveToFirst()) {
rv = csr.getLong(0);
}
csr.close();
return rv;
}
}
getNextQuestionID
我已经评论了查询的解析结果
SELECT * FROM questions LEFT JOIN progress ON questions._id = progress.questionref WHERE progress._id IS NULL ORDER BY questions.number ASC
问题
进步
您还可能注意到,为进度表创建的表不在
创建时的回调函数
createProgresstable
方法只允许独立调用它(例如,从
MainActivity
主要活动
public class MainActivity extends AppCompatActivity {
DBHelper questions;
TextView mQuestion;
TextView mAnswer1;
TextView mAnswer2;
TextView mAnswer3;
TextView mAnswer4;
CheckBox mCheckBox1;
CheckBox mCheckBox2;
CheckBox mCheckBox3;
CheckBox mCheckBox4;
Button mSubmit;
long mCurrentQuestion = 0;
int mCorrectAnswer = -1;
int mCurrentAnswer = -1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mQuestion = (TextView) findViewById(R.id.question);
mAnswer1 = (TextView) findViewById(R.id.answer1_text);
mAnswer2 = (TextView) findViewById(R.id.answer2_text);
mAnswer3 = (TextView) findViewById(R.id.answer3_text);
mAnswer4 = (TextView) findViewById(R.id.answer4_text);
mCheckBox1 = (CheckBox) findViewById(R.id.answer1_checkbox);
mCheckBox2 = (CheckBox) findViewById(R.id.answer2_checkbox);
mCheckBox3 = (CheckBox) findViewById(R.id.answer3_checkbox);
mCheckBox4 = (CheckBox) findViewById(R.id.answer4_checkbox);
mSubmit = (Button) findViewById(R.id.submit);
mSubmit.setVisibility(View.INVISIBLE);
setCheckBoxListeners();
setSubmitButtonListener();
questions = new DBHelper(this); //Get Questions DBHelper
questions.createProgresstable(questions.getWritableDatabase());
if (questions.getRowCount() < 1) {
addQuestions();
}
displayCurrentQuestion();
}
@Override
protected void onResume() {
super.onResume();
mCurrentQuestion = questions.getNextQuestionID();
}
void displayCurrentQuestion() {
mQuestion.setText("Sorry no questions are ready as yet");
mAnswer1.setVisibility(View.INVISIBLE);
mAnswer2.setVisibility(View.INVISIBLE);
mAnswer3.setVisibility(View.INVISIBLE);
mAnswer4.setVisibility(View.INVISIBLE);
mCheckBox1.setVisibility(View.INVISIBLE);
mCheckBox2.setVisibility(View.INVISIBLE);
mCheckBox3.setVisibility(View.INVISIBLE);
mCheckBox4.setVisibility(View.INVISIBLE);
mSubmit.setVisibility(View.INVISIBLE);
Cursor csr = questions.getQuestionRow(mCurrentQuestion = questions.getNextQuestionID());
if (csr.moveToFirst()) {
mQuestion.setText(csr.getString(csr.getColumnIndex(DBHelper.QUESTIONCOLUMN)));
String answer1 = csr.getString(csr.getColumnIndex(DBHelper.ANSWER1COLUMN));
String answer2 = csr.getString(csr.getColumnIndex(DBHelper.ANSWER2COLUMN));
String answer3 = csr.getString(csr.getColumnIndex(DBHelper.ANSWER3COLUMN));
String answer4 = csr.getString(csr.getColumnIndex(DBHelper.ANSWER4COLUMN));
mCorrectAnswer = csr.getInt(csr.getColumnIndex(DBHelper.CORRECTCOLUMN));
if (answer1.length() > 0) {
mAnswer1.setText(answer1);
mAnswer1.setVisibility(View.VISIBLE);
mCheckBox1.setVisibility(View.VISIBLE);
}
if (answer2.length() > 0) {
mAnswer2.setText(answer2);
mAnswer2.setVisibility(View.VISIBLE);
mCheckBox2.setVisibility(View.VISIBLE);
}
if (answer3.length() > 0) {
mAnswer3.setText(answer3);
mAnswer3.setVisibility(View.VISIBLE);
mCheckBox3.setVisibility(View.VISIBLE);
}
if (answer4.length() > 0) {
mAnswer4.setText(answer4);
mAnswer4.setVisibility(View.VISIBLE);
mCheckBox4.setVisibility(View.VISIBLE);
}
}
csr.close();
}
void submitQuestion() {
String questionresult = "Incorrect.";
if (mCurrentAnswer == mCorrectAnswer) {
questionresult = " Correct.";
questions.insertProgress(mCurrentQuestion);
}
Toast.makeText(this,
"Submitted Question " +
Long.toString(mCurrentQuestion) +
" Your answer was " + questionresult
,
Toast.LENGTH_SHORT
).show();
displayCurrentQuestion();
}
void setSubmitButtonListener() {
mSubmit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
submitQuestion();
}
});
}
void setCheckBoxListeners() {
mCheckBox1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if(b) {
mCheckBox2.setChecked(false);
mCheckBox3.setChecked(false);
mCheckBox4.setChecked(false);
mSubmit.setVisibility(View.VISIBLE);
mCurrentAnswer = 1;
}
}
});
mCheckBox2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if(b) {
mCheckBox1.setChecked(false);
mCheckBox3.setChecked(false);
mCheckBox4.setChecked(false);
mSubmit.setVisibility(View.VISIBLE);
mCurrentAnswer = 2;
}
}
});
mCheckBox3.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if(b) {
mCheckBox1.setChecked(false);
mCheckBox2.setChecked(false);
mCheckBox4.setChecked(false);
mSubmit.setVisibility(View.VISIBLE);
mCurrentAnswer = 3;
}
}
});
mCheckBox4.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if(b) {
mCheckBox1.setChecked(false);
mCheckBox2.setChecked(false);
mCheckBox3.setChecked(false);
mSubmit.setVisibility(View.VISIBLE);
mCurrentAnswer = 4;
}
}
});
}
void addQuestions() {
questions.insertQuestion("What was the name that nobody should have known?",
1,
"The Man with no Name.",
"Alan Parson Ah Ha.",
"Engelbert Humperdink.",
"Rumplestiltskin.",
4
);
questions.insertQuestion("What Band released the Album entitled Crime of the Cetury",
2,
"The Tramps",
"Super Tramp",
"Trankenstiens Feast",
"Tranvison Vamp",
2
);
questions.insertQuestion("Where is the worlds only Treacle Mine?",
3,
"Ginge",
"Ardington",
"Lockinge",
"Peasemoore",
1
);
}
}
希望上述内容不会让人望而却步,基本上有很多重复。
questions.createProgresstable(questions.getWritableDatabase());
这个片段只是为了添加一些问题,所以我测试:-
if (questions.getRowCount() < 1) {
addQuestions();
}
displayCurrentQuestion();
如果您有什么不明白的地方,请随时提问。
