无法在一个动作中隐藏多个NSButton？

Question

我想将“TheButton”设置为禁用，将“TheLastButton”设置为不隐藏。 TheButton将禁用，但TheLastButton只是保持隐藏状态。 这是代码：

-(IBAction)buttonPressed:(id)sender{

    NSButton *TheButton = sender;
    [TheButton setEnabled: NO];

    [_spinner setHidden:NO];
    [_spinner setIndeterminate:YES];
    [_spinner setUsesThreadedAnimation:YES];
    [_spinner startAnimation:nil];

    NSLog(@"started");

    //1
    NSTask *task = [[NSTask alloc] init];

    //2
    task.launchPath = @"/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister";
     [task setArguments:[NSArray arrayWithObjects: @"-kill", @"-seed", @"-r", @"-f", @"-v", @"-domain local", @"-domain user", @"-domain system", nil]];

     NSLog(@"finished");

    [_spinner setHidden:YES];

    NSButton *TheLastButton = sender;
    [TheLastButton setHidden:NO];