NSButtonCell悬停图片,点击透明背景？

Question

我已经实现了一个带有图像的NSButton.

当用户将其悬停时,图像会变为其他内容,然后重新开启.

---

正常状态:

在悬停时:

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我用的代码NSButtonCell是:

界面:

#import <Foundation/Foundation.h>

@interface DKHoverButtonCell : NSButtonCell 
{
    NSImage *_oldImage;
    NSImage *hoverImage;
}

@property (retain) NSImage *hoverImage;

@end

实施:

#import "DKHoverButtonCell.h"

@interface NSButtonCell()
- (void)_updateMouseTracking;
@end

@implementation DKHoverButtonCell

@synthesize hoverImage;

- (void)mouseEntered:(NSEvent *)event {
    if (hoverImage != nil && [hoverImage isValid]) {
        _oldImage = [[(NSButton *)[self controlView] image] retain];
        [(NSButton *)[self controlView] setImage:hoverImage];
    }
}

- (void)mouseExited:(NSEvent *)event {
    if (_oldImage != nil && [_oldImage isValid]) {
        [(NSButton *)[self controlView] setImage:_oldImage];
        [_oldImage release];
        _oldImage = nil;
    }
}

- (void)_updateMouseTracking {
    [super _updateMouseTracking];
    if ([self controlView] != nil && [[self controlView] respondsToSelector:@selector(_setMouseTrackingForCell:)]) {
        [[self controlView] performSelector:@selector(_setMouseTrackingForCell:) withObject:self];
    }
}

- (void)setHoverImage:(NSImage *)newImage {
    [newImage retain];
    [hoverImage release];
    hoverImage = newImage;
    [[self controlView] setNeedsDisplay:YES];
}

- (void)dealloc {
    [_oldImage release];
    [hoverImage release];
    [super dealloc];
}

@end

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现在,问题在于:

• 虽然上面的控件100%工作(带有"X"圆形图像和透明背景"),但当用户点击它时,它会显示"白色"背景,而不会保留我原来的"透明"背景
• 我该如何解决这个问题？

Answer 1

您需要将按钮的类型更改为瞬时更改.您可以在"属性"检查器中更改它:

或以编程方式更改:

[button setButtonType:NSMomentaryChangeButton];