这是错误,它说索引超出范围,但我不知道如何解决它,有一些土耳其语单词但它们并不重要,我认为:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.burhanozen.nothesaplama, PID: 26919
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.example.burhanozen.nothesaplama/com.example.burhanozen.nothesaplama.MainActivity}: android.database.CursorIndexOutOfBoundsException: Index 1 requested, with a size of 1
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at ........
我试图存储某种学生信息。我有这些错误,我在下面分享代码。 这是我的 MainActivity:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val toolbar = findViewById(R.id.toolbar) as Toolbar
setSupportActionBar(toolbar)
val fab = findViewById(R.id.fab) as FloatingActionButton
fab.setOnClickListener {
val intent = Intent(this@MainActivity,NotEkrani::class.java)
startActivity(intent) }
val studentsArray = ArrayList<String>()
val arrayAdapter = ArrayAdapter(this,android.R.layout.simple_list_item_1,studentsArray)
listView.adapter= arrayAdapter
try{
val myDatabase = this.openOrCreateDatabase("student", Context.MODE_PRIVATE,null)
myDatabase.execSQL("CREATE TABLE IF NOT EXISTS students (isim TEXT," +
" dersbir TEXT, dersbirkredi TEXT, dersbirort TEXT," +
" dersiki TEXT, dersikikredi TEXT, dersikiort TEXT) ")
val cursor = myDatabase.rawQuery("select * from students",null)
val nameIx = cursor.getColumnIndex("isim")
val dersbirIx = cursor.getColumnIndex("dersbir")
val dersbirkrediIx = cursor.getColumnIndex("dersbirkredi")
val dersbirortIx = cursor.getColumnIndex("dersbirort")
val dersikiIx = cursor.getColumnIndex("dersiki")
val dersikikrediIx = cursor.getColumnIndex("dersikikredi")
val dersikiortIx = cursor.getColumnIndex("dersikiort")
cursor.moveToNext()
while (cursor != null){
studentsArray.add(cursor.getString(nameIx))
studentsArray.add(cursor.getString(dersbirIx))
studentsArray.add(cursor.getString(dersbirkrediIx))
studentsArray.add(cursor.getString(dersbirortIx))
studentsArray.add(cursor.getString(dersikiIx))
studentsArray.add(cursor.getString(dersikikrediIx))
studentsArray.add(cursor.getString(dersikiortIx))
cursor.moveToNext()
arrayAdapter.notifyDataSetChanged()
}
while (cursor!=null){
cursor!!.close()
}
}catch (e:SQLException){
}
这是我的第二个 Activity 页面,我在这里没有任何错误,但这可能会有所帮助。我在这里写了数据库代码。
fun kaydet(view:View){
val isim = isim.text.toString()
val dersbir = dersbir.text.toString()
val dersbirkredi = dersbirkredi.text.toString()
val dersbirort = dersbirort.text.toString()
val dersiki = dersiki.text.toString()
val dersikikredi = dersikikredi.text.toString()
val dersikiort = dersikiort.text.toString()
try {
val myDatabase = openOrCreateDatabase("student", Context.MODE_PRIVATE,null)
myDatabase.execSQL("CREATE TABLE IF NOT EXISTS students (isim TEXT," +
" dersbir TEXT, dersbirkredi TEXT, dersbirort TEXT," +
" dersiki TEXT, dersikikredi TEXT, dersikiort TEXT) ")
val sqlString = "INSERT INTO students (isim,dersbir,dersbirkredi,dersbirort,dersiki,dersikikredi,dersikiort) VALUES(?,?,?,?,?,?,?)"
val statement = myDatabase.compileStatement(sqlString)
statement.bindString(1,isim)
statement.bindString(2,dersbir)
statement.bindString(3,dersbirkredi)
statement.bindString(4,dersbirort)
statement.bindString(5,dersiki)
statement.bindString(6,dersikikredi)
statement.bindString(7,dersikiort)
statement.execute()
}catch (e:SQLException){
}
val intent = Intent(this,MainActivity::class.java)
startActivity(intent)
}
最佳答案
将您的 while 循环更改为如下所示:
while (cursor.moveToNext()){
studentsArray.add(cursor.getString(nameIx))
...
}
(从您的代码中删除所有其他 cursor.moveToNext()
)
您正在 while 循环条件中检查 cursor != null
,但在您从游标读取所有行后它不会变为 null。
在上面的代码中,如果有下一行,cursor.moveToNext
返回 true。否则返回 false 并且循环终止。
而且,刚刚注意到,您应该将其更改为
while (cursor!=null){
cursor!!.close()
}
如果检查:
if (cursor!=null){
cursor.close()
}
或者,作为 Todd评论中建议,您可以使用自动关闭游标的高阶函数use
,这类似于 Java 7 try-with-resources。
cursor.use {
while (cursor.moveToNext()){
studentsArray.add(cursor.getString(nameIx))
...
}
}
关于java - Kotlin 数据库错误 CursorIndexOutOfBoundsException,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45784788/