我从表中读取一行时收到错误。我的应用程序是这样的：
当您单击列表视图中的项目时，另一个活动将开始加载编辑文本中的选定行列 - 这就是错误发生的位置。
public class DVD_activity extends AppCompatActivity {
String a;
String b;
DB_Worker dw;
int x;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dvd_activity);
NapojAdapter();
pridajListener();
}
private void NapojAdapter() {
dw = new DB_Worker(this);
SimpleCursorAdapter myAdapter = new SimpleCursorAdapter(this,R.layout.dvd_list_layout,dw.VratKurzorD(),new String[] { DVD.KEY_ID,
DVD.KEY_title,DVD.KEY_autor},new int[] {R.id.id2, R.id.nazov, R.id.autor},0);
ListView lv = (ListView)findViewById(R.id.listView2);
lv.setAdapter(myAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_dvd_activity, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void button4click(View view) {
Intent intent = new Intent (this, Pridaj_DVD.class);
String verzia = "1";
intent.putExtra("verzia",verzia);
startActivityForResult(intent, 1);
}
private void pridajListener() {
AdapterView.OnItemClickListener mMessageClickedHandler = new AdapterView.OnItemClickListener() {public void onItemClick(AdapterView parent, View v, int position, long id) {
TextView lv = (TextView)v.findViewById(R.id.id2);
x = Integer.parseInt(lv.getText().toString());
DVD s = dw.getDVD(x);
a =s.title;
b = s.autor;
String verzia = "2";
Intent intent = new Intent(DVD_activity.this,Pridaj_DVD.class);
intent.putExtra("verzia", verzia);
intent.putExtra("a",a);
intent.putExtra("b",b);
startActivityForResult(intent, 1);
}};
ListView myList= (ListView) findViewById(R.id.listView2);
myList.setOnItemClickListener(mMessageClickedHandler);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if (resultCode == 0) {
DVD s = new DVD();
s.title = data.getStringExtra("a");
s.autor = data.getStringExtra("b");
dw.addDVD(s);
NapojAdapter();
}
if (resultCode == 1) {
dw.deleteDVD(x);
NapojAdapter();
}
if (resultCode == 2) {
a = data.getStringExtra("a");
b = data.getStringExtra("b");
dw.updateDVD(Integer.toString(x),a,b);
NapojAdapter();
}
}
}
}
这是DB_WORKER类：
public class DB_Worker {
public SQLiteDatabase db;
private DB_Helper dbHelper;
public DB_Worker(Context context) {
dbHelper = new DB_Helper(context);
db = dbHelper.getWritableDatabase();
}
public void addDVD(DVD s) {
ContentValues values = new ContentValues();
values.put(DVD.KEY_title, s.title);
values.put(DVD.KEY_autor, s.autor);
long newRowId = db.insert(DVD.TABLE,null,values);
}
public DVD getDVD(long ID) {
DVD s = new DVD();
VratKurzorD();
String[] projection = {DVD.KEY_title, DVD.KEY_autor};
String selection = DVD.KEY_ID;
String[] selectionArgs = {""+ID};
Cursor c = db.query(DVD.TABLE,projection,selection,selectionArgs,null,null,null);
s.DVD_ID = ID;
s.title = c.getString(c.getColumnIndex(DVD.KEY_title));
s.autor = c.getString(c.getColumnIndex(DVD.KEY_autor));
c.close();
return s;
}
public void updateDVD(String ID, String title, String autor)
{
ContentValues cv = new ContentValues();
cv.put(DVD.KEY_title,title);
cv.put(DVD.KEY_autor, autor);
db.update(DVD.TABLE, cv, DVD.KEY_ID + "= ?", new String[]{ID});
}
public void deleteDVD(int ID) {
db.delete(DVD.TABLE, DVD.KEY_ID + "= ?", new String[]{"" + ID});
}
public Cursor VratKurzorD() {
Cursor c = db.rawQuery("select * from "+DVD.TABLE, null);
c.moveToFirst();
return c;
}
}
这是错误：
12-03 23:11:42.240 2067-2067/com.example.lowrider.pozicovna E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: com.example.lowrider.pozicovna, PID: 2067 java.lang.IllegalArgumentException: Cannot bind argument at index 1 because the index is out of range. The statement has 0 parameters.
at android.database.sqlite.SQLiteProgram.bind(SQLiteProgram.java:212)
at android.database.sqlite.SQLiteProgram.bindString(SQLiteProgram.java:166)
at android.database.sqlite.SQLiteProgram.bindAllArgsAsStrings(SQLiteProgram.java:200)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1316)
at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1163)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1034)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1202)
at com.example.lowrider.pozicovna.DB_Worker.getDVD(DB_Worker.java:78)
at com.example.lowrider.pozicovna.DVD_activity$1.onItemClick(DVD_activity.java:66)
at android.widget.AdapterView.performItemClick(AdapterView.java:310)
at android.widget.AbsListView.performItemClick(AbsListView.java:1145)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3042)
at android.widget.AbsListView$3.run(AbsListView.java:3879)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
答案 0 :(得分：0)
来自日志的信息：Cannot bind argument at index 1 because the index is out of range. The statement has 0 parameters.表示您在某个地方撰写的查询信息如下：
Select * from table并不需要任何参数，但是你提供了论证。
因此，您应该在代码中搜索没有?的查询，但是您将参数传递给函数。
答案 1 :(得分：0)
方法getDVD(long ID)更改
String selection = DVD.KEY_ID;
到
String selection = DVD.KEY_ID + "=?";
更新1：
此外，添加对moveToFirst()的调用以将光标定位到第一行：
Cursor c = db.query(DVD.TABLE,projection,selection,selectionArgs,null,null,null);
c.moveToFirst();
如果游标至少包含一行，这将有效。如果游标可能为空，则需要检查返回的布尔状态。