IllegalStateException光标错误 [英] IllegalStateException Cursor Error
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问题描述
在applecation中，在第一轮，它可以推动通过活动。但是后来这是一个错误。
SQLiteDatabase mDb;
Database3 mHelper;
SQLiteDatabase mDb2;
数据库mHelper2;
private Cursor mCursor;
private String name;
private String image;
private String location;
private String info;
private String shop;
private String mcontact;
mHelper2 = new Database（this，shop）;
mDb2 = mHelper2.getWritableDatabase（）;
mHelper2.onUpgrade（mDb2,1,1）;
if（info.equalsIgnoreCase（null））{
AlertDialog.Builder builder = new AlertDialog.Builder（Activity_Mall_Floor.this）;
builder.setTitle（楼层说明）;
builder.setMessage（No Floor information of+ name）;
builder.setNeutralButton（OK，null）;
builder.show（）;
}
else {
ListView listView1 =（ListView）findViewById（R.id.listView2）;
mHelper = new Database3（this，info）;
mDb = mHelper.getWritableDatabase（）;
mHelper.onUpgrade（mDb，1，1）;
mCursor = mDb.rawQuery（SELECT+ Database3.COL_FLOOR +，
+ Database3.COL_IMAGE +FROM+ Database3.TABLE_NAME，null）;
ArrayList< String> dirArray = new ArrayList< String>（）;
mCursor.moveToFirst（）;
while（！mCursor.isAfterLast（））{
dirArray.add（mCursor.getString
（mCursor.getColumnIndex（Database3.COL_FLOOR）））;
mCursor.moveToNext（）;
}
ArrayAdapter< String> adapterDir =
new ArrayAdapter< String>（getApplicationContext（）
，android.R.layout.simple_list_item_1，dirArray）;
listView1.setAdapter（adapterDir）;
listView1.setOnItemClickListener（new OnItemClickListener（）{
public void onItemClick（AdapterView<？> arg0，View arg1，int arg2，
long arg3）{
mCursor.moveToPosition arg2）;
String floorName = mCursor.getString（mCursor.getColumnIndex（Database3.COL_FLOOR））;
String mapFloor = mCursor.getString（mCursor.getColumnIndex（Database3.COL_IMAGE））;
String floor =;
if（floorName.equalsIgnoreCase（1st Floor））
floor =1;
else if（floorName.equalsIgnoreCase $ 2;
else if（floorName.equalsIgnoreCase（3rd Floor））
floor =3;
else
floor =4;
mCursor = mDb2.rawQuery（SELECT DISTINCT+ Database.COL_NAME
+FROM+ Database.TABLE_NAME
+WHERE+ Database.COL_FLOOR +='+ floor +'，null）;
ArrayList< String> dirArray = new ArrayList< String>（）;
mCursor.moveToFirst（）;
while（！mCursor.isAfterLast（））{
dirArray.add（mCursor.getString
（mCursor.getColumnIndex（Database.COL_NAME）））;
mCursor.moveToNext（）;
}
Intent intent = new Intent（getApplicationContext（），Activity_Mall_FMap.class）;
Bundle bundle = new Bundle（）;
bundle.putString（Floorname，floorName）;
bundle.putString（Mapfloor，mapFloor）;
bundle.putString（Shop，shop）;
intent.putExtra（FloorList，dirArray）;
intent.putExtras（bundle）;
startActivity（intent）;
}
}）;
}
错误表单logcat
02-12 01：31：46.917：E / AndroidRuntime（11370）：FATAL EXCEPTION：main
02-12 01：31：46.917：E / AndroidRuntime（11370） ：java.lang.IllegalStateException：无法从CursorWindow读取行0，col -1。在访问数据之前，确保光标正确初始化。
02-12 01：31：46.917：E / AndroidRuntime（11370）：android.database.CursorWindow.nativeGetString（Native Method）
02-12 01：31：46.917：E / AndroidRuntime（11370 ）：at android.database.CursorWindow.getString（CursorWindow.java:442）
02-12 01：31：46.917：E / AndroidRuntime（11370）：在android.database.AbstractWindowedCursor.getString（AbstractWindowedCursor.java： 51）
02-12 01：31：46.917：E / AndroidRuntime（11370）：at com.test.mall.Activity_Mall_Floor $ 1.onItemClick（Activity_Mall_Floor.java:85）
02-12 01:31 ：46.917：E / AndroidRuntime（11370）：在android.widget.AdapterView.performItemClick（AdapterView.java:292）
02-12 01：31：46.917：E / AndroidRuntime（11370）：在android.widget。 AbsListView.performItemClick（AbsListView.java:1068）
02-12 01：31：46.917：E / AndroidRuntime（11370）：在android.widget.AbsListView $ PerformClick.run（AbsListView.java:2525）
这是错误行85
String floorName = mCursor.getString（m Cursor.getColumnIndex（Database3.COL_FLOOR））;
String mapFloor = mCursor.getString（mCursor.getColumnIndex（Database3.COL_IMAGE））;
感谢您的指导。
解决方案
修复：
- 尝试通过moveToFirst定位游标，然后从中读取数据。
-
关闭光标if if（c.moveToFirst（））{}
-
检查null.e，g; if（c！= null&& c.moveToFirst（））{}
-
检查count.e，g; （c！= null&& c.getCount（）> 0&& c.moveToFirst（））{}
Sorry for the repeat Question.but I try to make many way doesn't work In applecation,In the first round, it can push through Activity. But back then it was a mistake.
SQLiteDatabase mDb;
Database3 mHelper;
SQLiteDatabase mDb2;
Database mHelper2;
private Cursor mCursor;
private String name;
private String image;
private String location;
private String info;
private String shop;
private String mcontact;
mHelper2 = new Database(this,shop);
mDb2 = mHelper2.getWritableDatabase();
mHelper2.onUpgrade(mDb2, 1, 1);
if (info.equalsIgnoreCase("null")){
AlertDialog.Builder builder = new AlertDialog.Builder(Activity_Mall_Floor.this);
builder.setTitle("Floor Description");
builder.setMessage("No Floor information of "+name);
builder.setNeutralButton("OK", null);
builder.show();
}
else {
ListView listView1 = (ListView)findViewById(R.id.listView2);
mHelper = new Database3(this,info);
mDb = mHelper.getWritableDatabase();
mHelper.onUpgrade(mDb, 1, 1);
mCursor = mDb.rawQuery("SELECT " + Database3.COL_FLOOR + ", "
+ Database3.COL_IMAGE+ " FROM " + Database3.TABLE_NAME, null);
ArrayList<String> dirArray = new ArrayList<String>();
mCursor.moveToFirst();
while ( !mCursor.isAfterLast() ){
dirArray.add(mCursor.getString
(mCursor.getColumnIndex(Database3.COL_FLOOR)));
mCursor.moveToNext();
}
ArrayAdapter<String> adapterDir =
new ArrayAdapter<String>(getApplicationContext()
, android.R.layout.simple_list_item_1, dirArray);
listView1.setAdapter(adapterDir);
listView1.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
mCursor.moveToPosition(arg2);
String floorName = mCursor.getString(mCursor.getColumnIndex(Database3.COL_FLOOR));
String mapFloor = mCursor.getString(mCursor.getColumnIndex(Database3.COL_IMAGE));
String floor = "";
if(floorName.equalsIgnoreCase("1st Floor"))
floor = "1";
else if (floorName.equalsIgnoreCase("2nd Floor"))
floor = "2";
else if (floorName.equalsIgnoreCase("3rd Floor"))
floor = "3";
else
floor = "4";
mCursor = mDb2.rawQuery("SELECT DISTINCT " + Database.COL_NAME
+" FROM " + Database.TABLE_NAME
+" WHERE " + Database.COL_FLOOR + " = '" + floor +"' ", null);
ArrayList<String> dirArray = new ArrayList<String>();
mCursor.moveToFirst();
while ( !mCursor.isAfterLast() ){
dirArray.add(mCursor.getString
(mCursor.getColumnIndex(Database.COL_NAME)));
mCursor.moveToNext();
}
Intent intent = new Intent(getApplicationContext(), Activity_Mall_FMap.class);
Bundle bundle = new Bundle();
bundle.putString("Floorname", floorName);
bundle.putString("Mapfloor", mapFloor);
bundle.putString("Shop", shop);
intent.putExtra("FloorList",dirArray);
intent.putExtras(bundle);
startActivity(intent);
}
});
}
Error form logcat
02-12 01:31:46.917: E/AndroidRuntime(11370): FATAL EXCEPTION: main
02-12 01:31:46.917: E/AndroidRuntime(11370): java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
02-12 01:31:46.917: E/AndroidRuntime(11370): at android.database.CursorWindow.nativeGetString(Native Method)
02-12 01:31:46.917: E/AndroidRuntime(11370): at android.database.CursorWindow.getString(CursorWindow.java:442)
02-12 01:31:46.917: E/AndroidRuntime(11370): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:51)
02-12 01:31:46.917: E/AndroidRuntime(11370): at com.test.mall.Activity_Mall_Floor$1.onItemClick(Activity_Mall_Floor.java:85)
02-12 01:31:46.917: E/AndroidRuntime(11370): at android.widget.AdapterView.performItemClick(AdapterView.java:292)
02-12 01:31:46.917: E/AndroidRuntime(11370): at android.widget.AbsListView.performItemClick(AbsListView.java:1068)
02-12 01:31:46.917: E/AndroidRuntime(11370): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2525)
and this is error line 85
String floorName = mCursor.getString(mCursor.getColumnIndex(Database3.COL_FLOOR));
String mapFloor = mCursor.getString(mCursor.getColumnIndex(Database3.COL_IMAGE));
Thank you for Guidance.
解决方案
Fix:
Try to position cursor by moveToFirst before reading data from it.
Close the cursor after if ( c.moveToFirst()) {}
check for null.e,g; if (c != null && c.moveToFirst()) {}
check for count.e,g; (c != null && c.getCount() >0 && c.moveToFirst()){}
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