BlackBerry Application中的持久对象
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问候，
我一直在尝试在BlackBerry Application中使用持久对象。
我正在创建一个登录页面，我可以在其中保存用户名和密码。
以下是我在登录页面中使用的代码
public final class LoginScreen extends MainScreen
{
private BasicEditField useremailField;
private PasswordEditField passwordField;
public HorizontalFieldManager hfm = new HorizontalFieldManager (FIELD_VCENTER);
public Hashtable persistentHashtable;
public PersistentObject persistentObject;
public static final long KEY = 0x9df9f961bc6d6baL;
public LoginScreen()
{
super( MainScreen.VERTICAL_SCROLL | MainScreen.VERTICAL_SCROLLBAR );
// Set the displayed title of the screen
setTitle(new LabelField(\"Log In\", LabelField.HCENTER| LabelField.USE_ALL_WIDTH));
persistentObject = PersistentStore.getPersistentObject(KEY);
useremailField = new BasicEditField( \"Email Address:\", \"\", 100, BasicEditField.EDITABLE );
passwordField = new PasswordEditField( \"Password: \", \"\", 100, PasswordEditField.EDITABLE);
ButtonField registerField = new ButtonField( \"Register\", ButtonField.CONSUME_CLICK | ButtonField.FIELD_LEFT);
ButtonField loginField = new ButtonField( \"Login\", ButtonField.CONSUME_CLICK | ButtonField.FIELD_RIGHT);
add(new LabelField(\"\\n\\n\"));
add( useremailField );
add(new LabelField(\"\\n\"));
add( passwordField);
add(new LabelField(\"\\n\"));
hfm.add(registerField);
hfm.add(loginField);
setStatus(hfm);
loginField.setChangeListener( new FieldChangeListener()
{
public void fieldChanged( Field arg0, int arg1 )
{
login();
}
} );
persistentHashtable.put(\"UsernameData\", useremailField);
persistentHashtable.put(\"PasswordData\", passwordField);
persistentObject.commit();
}
private void login() {
UiApplication ui = UiApplication.getUiApplication();
ui.pushScreen(new Loggedin());
}
}
public class Loggedin extends MainScreen
{
private LabelField username;
private LabelField password;
public static PersistentObject persistentObject;
public Loggedin()
{
super( MainScreen.VERTICAL_SCROLL | MainScreen.VERTICAL_SCROLLBAR );
setTitle( \"Registration Form\" );
if (persistentObject.getContents() == null) {
persistentHashtable = new Hashtable();
persistentObject.setContents(persistentHashtable);
}
else {
persistentHashtable = (Hashtable)persistentObject.getContents();
}
if (persistentHashtable.containsKey(\"EditData\")) {
username.setText((String)persistentHashtable.get(\"UsernameData\"));
}
if (persistentHashtable.containsKey(\"BoolData\")) {
password.setText((String)persistentHashtable.get(\"PasswordData\"));
}
}
}
没有找到相关结果
已邀请:
2 个回复
穗揣
掸牛浓疗
并提交到persistentObject！我认为这就是您不保存值的原因！ 请参阅以下示例：private static PersistentObject persistentStore; private static Object[] data = new Object[1]; //Load Username & Password public static void LoadContents(){ Object[] temp; try{ persistentStore = PersistentStore.getPersistentObject(GI.PERSISTANCEID); if(persistentStore.getContents()!=null){ temp = (Object[]) persistentStore.getContents(); if(temp!=null){ data[0] = temp[0]; data[1] = temp[1]; } username.setText((data[0]!=null)?(String)data[0]:\"\"); password.setText((data[1]!=null)?(String)data[1]:\"\"); }else{ data = new Object[1]; } }catch(NullPointerException e){ System.out.println(\"CA: S NPE \"+e.getMessage()); }catch(Exception e){ System.out.println(\"CA: S E \"+e.getMessage()); } } //Save Username & Password public static void saveUsername(String version){ data[0] = version; persistentStore.setContents(data); persistentStore.commit(); } public static void savePassword(String password){ data[1] = password; persistentStore.setContents(data); persistentStore.commit(); }