我创建了一个从数据库读取数据并将其放入 String
数组的方法。
Android Studio没有给出语法错误,但当我启动我的应用程序时,日志显示:
03-19 16:31:20.938 2518-2518/com.mms.dailypill E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mms.dailypill, PID: 2518
java.lang.ArrayIndexOutOfBoundsException: length=0; index=0
at com.mms.dailypill.DBManager.getMedicines(DBManager.java:56)
该方法的代码如下:
public String[] getMedicines()
{
SQLiteDatabase db = dbManager.getWritableDatabase();
String[] columns = {dbManager.getName(), dbManager.getFormat(), dbManager.getAmount(), dbManager.getExp_date(), dbManager.getTime()};
Cursor cursor = db.query(dbManager.getTableName(), columns, null, null, null, null, null);
String[] medicines = {};
String name, format, exp_date, time;
int amount;
int count = 0;
while(cursor.moveToNext())
{
name = cursor.getString(0);
format = cursor.getString(1);
amount = cursor.getInt(2);
exp_date = cursor.getString(3);
time = cursor.getString(4);
medicines[count] = "Name: " + name + " Format: " + format + " Amount: " + amount + " Expiration Date: " + exp_date + " Time: " + time;
count++;
}
db.close();
return medicines;
}
根据日志显示,异常出现在第56行:
time = cursor.getString(4);
我读取的表格有6列:
id
, name
, format
, amount
, exp_date
, time
。我只想显示整个表格,但不包括id
列,所以当我调用getString()
方法时,我从索引1
开始而不是从0
开始。我真的不明白问题出在哪里,所以如果有人能帮助我,我将非常感激。 提前致谢!