在C說話中應用對數函數的辦法。本站提示廣大學習愛好者：（在C說話中應用對數函數的辦法）文章只能為提供參考，不一定能成為您想要的結果。以下是在C說話中應用對數函數的辦法正文
比來做項目，碰著一種雙向滑動條，本身完成了一下，隨意寫一下思緒，便利今後開辟，防止反復寫代碼，今後粘貼就好了。封裝了一下，代碼以下：
#import <UIKit/UIKit.h> typedef NSString* (^HLDoubleSlideViewSwitchStrBock)(CGFloat count); @interface HLDoubleSlideView : UIView @property(nonatomic,assign)CGFloat maxValue; @property(nonatomic,assign)CGFloat minValue; @property(nonatomic,assign)CGFloat currentLeftValue; @property(nonatomic,assign)CGFloat currentRightValue; //格局化顯示文本 @property(nonatomic,copy)HLDoubleSlideViewSwitchStrBock block; @end
源文件以下：
#import "HLDoubleSlideView.h"
#import "UIView+Add.h"
@interface HLDoubleSlideView ()<UIGestureRecognizerDelegate>
@property(nonatomic,strong)UIImageView *leftImageView;
@property(nonatomic,strong)UIImageView *rightImageView;
@property(nonatomic,strong)UILabel *leftLabel;
@property(nonatomic,strong)UILabel *rightLabel;
@property(nonatomic,strong)UIButton *leftBtn;
@property(nonatomic,strong)UIButton *rightBtn;
@property(nonatomic,assign)CGFloat leftBtnOrgx;
@property(nonatomic,assign)CGFloat rightBtnOrgx;
@end
@implementation HLDoubleSlideView
-(id)init
{
if (self = [super init]) {
[self setupUI];
}
return self;
}
-(void)setupUI
{
_leftImageView = [[UIImageView alloc] init];
_leftImageView.image = [UIImage imageNamed:@"progressImage"];
_leftImageView.frame = CGRectMake(0, 5, 60, 40);
[self addSubview:_leftImageView];
_leftLabel = [[UILabel alloc] initWithFrame:_leftImageView.bounds];
_leftLabel.backgroundColor = [UIColor clearColor];
_leftLabel.font = [UIFont systemFontOfSize:13];
_leftLabel.textAlignment = NSTextAlignmentCenter;
_leftLabel.textColor = [UIColor whiteColor];
[_leftImageView addSubview:_leftLabel];
_rightImageView = [[UIImageView alloc] init];
_rightImageView.image = [UIImage imageNamed:@"progressImage"];
_rightImageView.frame = CGRectMake(0, 5, 60, 40);
[self addSubview:_rightImageView];
_rightLabel = [[UILabel alloc] initWithFrame:_rightImageView.bounds];
_rightLabel.backgroundColor = [UIColor clearColor];
_rightLabel.font = [UIFont systemFontOfSize:13];
_rightLabel.textAlignment = NSTextAlignmentCenter;
_rightLabel.textColor = [UIColor whiteColor];
[_rightImageView addSubview:_rightLabel];
_leftBtn = [UIButton buttonWithType:UIButtonTypeCustom];
_leftBtn.frame = CGRectMake(0, 50, 20,20);
_leftBtn.backgroundColor = [UIColor blueColor];
_leftBtn.layer.cornerRadius = 10;
[self addSubview:_leftBtn];
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureAction:)];
panGesture.delegate = self;
[_leftBtn addGestureRecognizer:panGesture];
_leftImageView.centerX = _leftBtn.centerX;
_rightBtn = [UIButton buttonWithType:UIButtonTypeCustom];
_rightBtn.backgroundColor = [UIColor blueColor];
_rightBtn.frame = CGRectMake(240, 50, 20, 20);
_rightBtn.layer.cornerRadius = 10;
panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureAction:)];
panGesture.delegate = self;
[_rightBtn addGestureRecognizer:panGesture];
_rightImageView.centerX = _rightBtn.centerX;
[self addSubview:_rightBtn];
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
return YES;
}
-(UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
NSLog(@"doubleView hitTest");
return [super hitTest:point withEvent:event];
}
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
NSLog(@"began");
[super touchesBegan:touches withEvent:event];
}
-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
NSLog(@"move");
[super touchesMoved:touches withEvent:event];
}
-(void)layoutSubviews
{
CGFloat centenX = (_currentLeftValue - _minValue) * (self.bounds.size.width - 20)/(_maxValue - _minValue) + 10;
_leftBtn.centerX = centenX;
if (_currentLeftValue != 0) {
CGFloat centenX = (_currentRightValue - _minValue) * (self.bounds.size.width - 20) / (_maxValue - _minValue) + 10;
_rightBtn.centerX = centenX;
}
else
{
_rightBtn.centerX = self.bounds.size.width - 10;
}
_leftImageView.centerX = _leftBtn.centerX;
_rightImageView.centerX = _rightBtn.centerX;
if (_block) {
_leftLabel.text = _block(_currentLeftValue);
_rightLabel.text = _block(_currentRightValue);
}
}
-(void)tapGestureAction:(UIPanGestureRecognizer*)panGesture
{
UIView *vw = panGesture.view;
CGPoint transPoint = [panGesture translationInView:self];
NSLog(@"x:%lf,y:%lf",transPoint.x,transPoint.y);
switch (panGesture.state) {
case UIGestureRecognizerStateBegan:
{
if ([vw isEqual:_leftBtn])
{
_leftBtnOrgx = _leftBtn.orgX;
NSLog(@"拖拽右邊按鈕");
}
else if([vw isEqual:_rightBtn])
{
_rightBtnOrgx = _rightBtn.orgX;
NSLog(@"拖拽左邊按鈕");
}
}
break;
case UIGestureRecognizerStateChanged:
{
if ([vw isEqual:_leftBtn])
{
CGFloat orginX = _leftBtn.orgX;
_leftBtn.orgX = _leftBtnOrgx + transPoint.x;
if (_leftBtn.orgX < 0) {
_leftBtn.orgX = 0;
}
else if(_leftBtn.orgX >= _rightBtn.orgX - 20)
{
_leftBtn.orgX = orginX;
}
_leftImageView.centerX = _leftBtn.centerX;
}
else if([vw isEqual:_rightBtn])
{
CGFloat orginX = _rightBtn.orgX;
_rightBtn.orgX = _rightBtnOrgx + transPoint.x;
if (_rightBtn.orgX >= self.bounds.size.width - 20) {
_rightBtn.orgX = self.bounds.size.width - 20;
}
else if(_rightBtn.orgX <= _leftBtn.orgX + 20)
{
_rightBtn.orgX = orginX;
}
_rightImageView.centerX = _rightBtn.centerX;
}
}
break;
case UIGestureRecognizerStateEnded:
{
}
break;
default:
break;
}
_currentLeftValue = _minValue + (_maxValue - _minValue) * ((_leftBtn.centerX - 10) / (self.bounds.size.width - 20));
_currentRightValue = _minValue + (_maxValue - _minValue) * ((_rightBtn.centerX - 10) / (self.bounds.size.width - 20));
if (_block) {
_leftLabel.text = _block(_currentLeftValue);
_rightLabel.text = _block(_currentRightValue);
}
NSLog(@"leftValue:%lf,rightValue:%lf",_currentLeftValue,_currentRightValue);
[self setNeedsDisplay];
}
-(void)setCurrentLeftValue:(CGFloat)currentLeftValue
{
_currentLeftValue = currentLeftValue;
CGFloat centenX = (currentLeftValue - _minValue) * (self.bounds.size.width - 20)/(_maxValue - _minValue) + 10;
_leftBtn.centerX = centenX;
[self setNeedsDisplay];
}
-(void)setCurrentRightValue:(CGFloat)currentRightValue
{
_currentRightValue = currentRightValue;
CGFloat centenX = (_currentRightValue - _minValue) * (self.bounds.size.width - 20) / (_maxValue - _minValue) + 10;
_rightBtn.centerX = centenX;
[self setNeedsDisplay];
}
-(void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, 3);
[[UIColor grayColor] setStroke];
CGContextMoveToPoint(context, 0, 60);
CGContextAddLineToPoint(context, self.bounds.size.width, 60);
CGContextStrokePath(context);
[[UIColor redColor] setStroke];
CGContextMoveToPoint(context, _leftBtn.orgX + 10, 60);
CGContextAddLineToPoint(context, _rightBtn.orgX,60);
CGContextStrokePath(context);
}
@end
應用以下：
HLDoubleSlideView *doubleSlideView = [[HLDoubleSlideView alloc] init];
doubleSlideView.backgroundColor = [UIColor whiteColor];//HLColor(244, 244, 244);
doubleSlideView.minValue = 1000;
doubleSlideView.maxValue = 10000;
doubleSlideView.block = ^NSString*(CGFloat count)
{
return [NSString stringWithFormat:@"%.0f元",count];
};
[self.view addSubview:doubleSlideView];
doubleSlideView.frame = CGRectMake(60, 64, 250, 80);
doubleSlideView.currentLeftValue = 1200;
doubleSlideView.currentRightValue = 10000;
運轉成果以下：
demo:https://github.com/jiangtaidi/HLDoubleSlideView.git
以上就是本文的全體內容，願望對年夜家的進修有所贊助。
