NSPopUpButton 不显示我上次保存的选择

Question

我无法弄清楚如何正确使用带有弹出菜单的NSPopUpButton class。

我有基本的工作。 我可以显示 select 并在我的NSPopUpButton versionsPopupOutlet PopupOutlet object （这是我的 PreferenceController 对象的一部分）中的弹出窗口 window 中保存我的选择。

PreferenceController object 是我的 Preferences window 程序。

我可以关闭并再次打开 Preferences window 它显示了我最后的选择！ 伟大的！

但是当我退出并再次运行我的程序时， NSPopUpButton versionsPopupOutlet object 不会显示我上次保存的选择（程序最终将使用它）。 它始终显示NSPopUpButton versionsPopupOutlet object 的弹出菜单中的第一项（可能正确也可能不正确）。

代码很简单。

PreferenceController.h是：

#import <AppKit/AppKit.h>


@interface PreferenceController : NSWindowController
{
    IBOutlet NSPopUpButton *versionsPopupOutlet;
}

- (IBAction)save:(id)sender;
- (IBAction)close:(id)sender;
@end

PreferenceController.m是：

#import "PreferenceController.h"


@implementation PreferenceController

- (id)init
{
    self = [super initWithWindowNibName:@"Preferences"];
    return self;
}

- (void)windowDidLoad
{
    NSDictionary *environment = [[NSProcessInfo processInfo] environment];
    NSString *commonlist = @"/bin/powerpc-apple-darwin:/usr/X11R6/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/sw/bin:/sw/sbin:/opt/local/bin";  // Added /opt/local/bin
    NSString *pathlist = [environment objectForKey:@"PATH"];
    NSArray *commonItems = [commonlist componentsSeparatedByString:@":"];
    NSArray *pathItems = [pathlist componentsSeparatedByString:@":"];
    NSString *path;
    BOOL duplicate;
    unsigned int i, h;

    for (i = 0; i < [commonItems count]; i++)
    {
        path = [[commonItems objectAtIndex:i] stringByAppendingString:@"/lame"];
        if ([[NSFileManager defaultManager] fileExistsAtPath:path])
            [versionsPopupOutlet addItemWithTitle:path];
    }

    for (i = 0; i < [pathItems count]; i++)
    {
        duplicate = FALSE;
        for (h = 0; h < [commonItems count]; h++)
        {
            if ([[pathItems objectAtIndex:i] isEqualToString:[commonItems objectAtIndex:h]])
                duplicate = TRUE;
        }
        if (!duplicate)
        {
            path = [[pathItems objectAtIndex:i] stringByAppendingString:@"/lame"];
            if ([[NSFileManager defaultManager] fileExistsAtPath:path])
                [versionsPopupOutlet addItemWithTitle:path];
        }
    }
}

- (IBAction)save:(id)sender
{
    if ([versionsPopupOutlet indexOfSelectedItem] == 0)
        [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:@"lamePath"];
    else
        [[NSUserDefaults standardUserDefaults] setObject:[versionsPopupOutlet titleOfSelectedItem] forKey:@"lamePath"];
    [self close];
}

- (IBAction)close:(id)sender
{
    [[self window] close];
}
@end

在我的主 GUI 程序中，我有：

+ (void)initialize
{
     NSMutableDictionary *defaultValues = [NSMutableDictionary dictionary];

    [defaultValues setObject:@"" forKey:@"lamePath"];

    [[NSUserDefaults standardUserDefaults] registerDefaults:defaultValues];
}

如您所见，弹出菜单的值通过上面显示的(IBAction)save:(id)sender方法中的[NSUserDefaults standardUserDefaults] setObject: forKey:方法存储在首选项文件中。 问题是如何设置弹出菜单以显示已保存首选项文件中弹出菜单中最后保存的项目？

我可以使用[[NSUserDefaults standardUserDefaults] objectForKey:@"lamePath"]获取首选项文件中最后保存的值。 但是，当我运行首选项 window 时，如何告诉弹出菜单显示最后保存的值？

Answer 1

我终于弄明白了。 我需要将以下内容添加到PreferenceController.m中(void)windowDidLoad()方法的末尾

[versionsPopupOutlet selectItemWithTitle:[[NSUserDefaults standardUserDefaults] objectForKey:@"lamePath"]];

上面的语句从 standardUserDefaults 读取最后保存的弹出菜单选择，然后在填充的弹出菜单中选择它。

所以PreferenceController.m中的(void)windowDidLoad()方法现在显示为：

- (void)windowDidLoad
{
    NSDictionary *environment = [[NSProcessInfo processInfo] environment];
    NSString *commonlist = @"/bin/powerpc-apple-darwin:/usr/X11R6/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/sw/bin:/sw/sbin:/opt/local/bin";  // Added /opt/local/bin
    NSString *pathlist = [environment objectForKey:@"PATH"];
    NSArray *commonItems = [commonlist componentsSeparatedByString:@":"];
    NSArray *pathItems = [pathlist componentsSeparatedByString:@":"];
    NSString *path;
    BOOL duplicate;
    unsigned int i, h;

    for (i = 0; i < [commonItems count]; i++)
    {
        path = [[commonItems objectAtIndex:i] stringByAppendingString:@"/lame"];
        if ([[NSFileManager defaultManager] fileExistsAtPath:path])
            [versionsPopupOutlet addItemWithTitle:path];
    }

    for (i = 0; i < [pathItems count]; i++)
    {
        duplicate = FALSE;
        for (h = 0; h < [commonItems count]; h++)
        {
            if ([[pathItems objectAtIndex:i] isEqualToString:[commonItems objectAtIndex:h]])
                duplicate = TRUE;
        }
        if (!duplicate)
        {
            path = [[pathItems objectAtIndex:i] stringByAppendingString:@"/lame"];
            if ([[NSFileManager defaultManager] fileExistsAtPath:path])
                [versionsPopupOutlet addItemWithTitle:path];
        }
    }
    [versionsPopupOutlet selectItemWithTitle:[[NSUserDefaults standardUserDefaults] objectForKey:@"lamePath"]];
}