我的代碼是這樣的錯誤吐司與空
public Database(Context context) {
super(context, dbname, null, dbversion);
try{
db=getWritableDatabase();
// TODO Auto-generated constructor stub
if (db.isOpen()){
Toast.makeText(null, "Database is open", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(null, "Database is Closed", Toast.LENGTH_LONG).show();
}
} catch(Exception e) {
Log.e(dbname, e.getMessage());
}
}
我得到異常的烤麪包和登錄貓顯示
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.example.manager/com.example.manager.MainActivity}:
java.lang.NullPointerException: println needs a message
你不能null作爲上下文,而不是null使用getApplicationContext或上下文或this或classname.this ... – 2013-04-24 14:49:24