显示时第二个 NIB 文件没有焦点

如何解决显示时第二个 NIB 文件没有焦点

我在 Xcode 12.3 的 Objective-C 项目中使用以下代码显示第二个 Nib 文件。显示 Nib 文件，但在单击之前没有焦点。如何让它在不被点击的情况下获得焦点？

- (IBAction)imageSplit:(id)sender {

[[self loadWithNibNamed:@"ImageSplit" owner:self ] display];

}

- (NSView *)loadWithNibNamed:(Nsstring *)nibNamed owner:(id)owner {

NSNib * nib = [[NSNib alloc] initWithNibNamed:nibNamed bundle:nil];

NSArray * objects;
if (![nib instantiateWithOwner:owner topLevelObjects:&objects]) {
    NSLog(@"Couldn't load nib named %@",nibNamed);
    return nil;
}

for (id object in objects) {
    if ([object isKindOfClass:[NSWindow class]]) {
        return object;
    }
}
return nil;

}