objective-c - 自定义NSSliderCell

我有点喜欢实现自定义滑块单元，该单元可以使用滚动条和旋钮的图像进行绘制。现在唯一的障碍是，当我快速拖动旋钮时，图像变得困惑。我已经发布了一个屏幕截图。

这是代码:

#import "customSliderCell.h"
@implementation customSliderCell
- (void)drawKnob:(NSRect)knobRect {

    NSImage * knob = knobImage;
 [[self controlView] lockFocus];
 [knob
 compositeToPoint:NSMakePoint(knobRect.origin.x,knobRect.origin.y+knobRect.size.height)
 operation:NSCompositeSourceOver];

[[self controlView] unlockFocus];
}
- (void)drawBarInside:(NSRect)rect flipped:(BOOL)flipped {
rect.size.height = 8;

    NSRect leftRect = rect;
    leftRect.origin.x=0;
    leftRect.origin.y=2;
    leftRect.size.width = knobrect.origin.x + (knobrect.size.width);
    [leftBarImage setSize:leftRect.size];
    [leftBarImage drawInRect:leftRect fromRect: NSZeroRect operation: NSCompositeSourceOver fraction:1];

    NSRect rightRect = rect;
    rightRect.origin.x=0;
    rightRect.origin.y=2;
    rightRect.origin.x = knobrect.origin.x;
    [rightBarImage setSize:rightRect.size];
    [rightBarImage drawInRect:rightRect fromRect: NSZeroRect operation: NSCompositeSourceOver fraction:1];
}

啊，我好亲近。非常感谢您提供有关此情况发生的原因以及解决方法的任何帮助，谢谢!

最佳答案

好的，就可以解决了。显然，滑块试图变得精巧，仅在旋钮所在的位置绘制。因此，显然，我必须始终通过覆盖Slider类中的setNeedsDisplayInRect来使rect始终无效。

#import "customSlider.h"

@implementation customSlider
-(void)setNeedsDisplayInRect:(NSRect)invalidRect{
    [super setNeedsDisplayInRect:[self bounds]];
}
@end

关于objective-c - 自定义NSSliderCell，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/3985816/