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[sld1 setThumbImage:[UIImage imageNamed:@"Blue.png"] forState:UIControlStateHighlighted];
[sld1 setThumbImage:[UIImage imageNamed:@"Blue.png"] forState:UIControlStateNormal     ];

这会导致滑块图像消失吗?我的都没有了。(拇指图像显示得很好。)

Apple的文档听起来我可以使用以上两行代码中的任何一个。(但我想我真的需要两者。)

而且我找不到任何关于“你必须始终做到所有 4”的信息:

Set the normal-state image.
Set the highlighted-state image.
Set the setMinimumTrackImage.
Set the setMaximumTrackImage.
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1 回答 1

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如果开始用图形自定义 UISlider,则必须设置至少 3 个图形。轨迹栏的左右两侧和拇指图像:

这是我上次使用 UISlider 时的做法:

    CGRect frame = CGRectMake(20.0f, 6.0, 280.0f, 20.0f);
    UISlider *customSlider = [[UISlider alloc] initWithFrame:frame];
    [customSlider addTarget:self action:@selector(sliderMove:) forControlEvents:UIControlEventValueChanged];
    [customSlider addTarget:self action:@selector(sliderStart:) forControlEvents:UIControlEventTouchDown];
    [customSlider addTarget:self action:@selector(sliderEnd:) forControlEvents:UIControlEventTouchUpInside];        
    [customSlider addTarget:self action:@selector(sliderEnd:) forControlEvents:UIControlEventTouchUpOutside];   

    // in case the parent view draws with a custom color or gradient, use a transparent color
    customSlider.backgroundColor = [UIColor clearColor];    
    UIImage *stetchLeftTrack = [[UIImage imageNamed:@"slider.png"]
                                stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0];

     UIImage *stetchRightTrack = [[UIImage imageNamed:@"slider_right.png"]
                                stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0];

    [customSlider setThumbImage: [UIImage imageNamed:@"slider-knop.png"] forState:UIControlStateNormal];
    [customSlider setMinimumTrackImage:stetchLeftTrack forState:UIControlStateNormal];
    [customSlider setMaximumTrackImage:stetchRightTrack forState:UIControlStateNormal];

在我的光学系统中,UISlider 或任何其他状态的突出显示状态是没有意义的,您的手指可能会覆盖拇指图像,因此用户永远不会看到它。我不确定它只是从 UIButton 扩展而来,也许它无法处理它?

于 2010-06-14T17:23:25.160 回答