增加拇指“点击区域”在UISlider [英] Increasing a thumbs "click area" in UISlider

问题描述

我正在创建一个自定义UISlider并且想知道，如何增加拇指图像的点击区域？下面的代码效果很好，除了拇指的点击区域保持不变。如果我没错，我相信标准拇指面积是19像素？让我们说我想用下面的代码将它增加到35px，我需要采取哪些步骤？请记住，我根本不是这个领域的专家。

I am creating a custom UISlider and wonder, how do you increase a thumb image's "click area" ? The code below works great, except the thumb's "click area" remains unchanged. If I am not wrong, I believe the standard thumb area is 19 px ? Lets say I would like to increase it to 35px with the following code below, what steps do I need to take? Keep in mind I am not an expert within this area at all.

编辑 以下代码已更正并准备好复制意大利面！希望对您有所帮助！

main.h

#import "MyUISlider.h"

@interface main : MLUIViewController <UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate, UIActionSheetDelegate, UIAlertViewDelegate, MFMailComposeViewControllerDelegate, UIGestureRecognizerDelegate, MLSearchTaskDelegate, MLDeactivateDelegate, MLReceiptDelegate>
{
  ..........

}

- (void)create_Custom_UISlider;

main.m

- (void)viewDidLoad
{

[self create_Custom_UISlider];
[self.view addSubview: customSlider];

}

- (void)create_Custom_UISlider
{
CGRect frame = CGRectMake(20.0, 320.0, 280, 0.0);


customSlider = [[MyUISlider alloc] initWithFrame:frame];

[customSlider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
// in case the parent view draws with a custom color or gradient, use a transparent color

customSlider.backgroundColor = [UIColor clearColor];

UIImage *stetchLeftTrack = [[UIImage imageNamed:@"blue_slider08.png"]
           stretchableImageWithLeftCapWidth: 10.0 topCapHeight:0.0];
UIImage *stetchRightTrack = [[UIImage imageNamed:@"blue_slider08.png"]
            stretchableImageWithLeftCapWidth: 260.0 topCapHeight:0.0];


[customSlider setThumbImage: [UIImage imageNamed:@"slider_button00"] forState:UIControlStateNormal];
[customSlider setMinimumTrackImage:stetchLeftTrack forState:UIControlStateNormal];
[customSlider setMaximumTrackImage:stetchRightTrack forState:UIControlStateNormal];


                    customSlider.minimumValue = 0.0;
                    customSlider.maximumValue = 1.0;
                    customSlider.continuous = NO;
                    customSlider.value = 0.00;

}

-(void) sliderAction: (UISlider *) sender{

if(sender.value !=1.0){
 [sender setValue: 0.00 animated: YES];
}
else{
[sender setValue 0.00 animated: YES];
 // add some code here depending on what you want to do!
  }
}

编辑（试图具有以下代码的子类）

EDIT (trying to subclass with the code below)

MyUISlider.h

#import <UIKit/UIKit.h>

@interface MyUISlider : UISlider {

}

@end

MyUISlider.m

#import "MyUISlider.h"

@implementation MyUISlider



- (CGRect)thumbRectForBounds:(CGRect)bounds trackRect:(CGRect)rect value:(float)value
{


return CGRectInset ([super thumbRectForBounds:bounds trackRect:rect value:value], 10 , 10);

}


@end

推荐答案

您必须在自定义子类<中覆盖 thumbRectForBounds：trackRect：value： / strong>（而不是像你在代码中那样自己调用方法，除了返回一个你甚至懒得检索的值之外什么都不做。）

You have to override thumbRectForBounds:trackRect:value: in a custom subclass (instead of calling the method yourself like you do in your code, which does nothing except returning a value that you don't even bother to retrieve).

thumbRectForBounds：trackRect：value：不是设置 tumb rect的方法，而是 get 它。滑块将在内部调用此 thumbRectForBounds：trackRect：value：方法以了解绘制拇指图像的位置，因此您需要覆盖它 - 如文档中所述 - 返回你想要的 CGRect （这样你想要的是35x35px）。

thumbRectForBounds:trackRect:value: is not a method to set the tumb rect, but to get it. The slider will internally call this thumbRectForBounds:trackRect:value: method to know where to draw the thumb image, so you need to override it — as explained in the documentation — to return the CGRect you want (so that it will be 35x35px as you wish).

这篇关于增加拇指“点击区域”在UISlider的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！