Question

我想实现这样的事情：

1-首先，我实现了这个视图：UnitSliderView：

使用此代码：

#import "UnitSliderView.h"

@implementation UnitSliderView

-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self != nil)
    {
        //initialization
        self.backgroundColor = [UIColor grayColor];
        [self initViews];
        [self initConstraints];
    }
    return self;
}

-(void)initViews
{
    _leftLabel = [[UILabel alloc] init];
    _leftLabel.textColor = [UIColor whiteColor];
    //self.leftLabel.text = @"John";
    [self addSubview:_leftLabel];

    _rightLabel = [[UILabel alloc] init];
    _rightLabel.textColor = [UIColor whiteColor];
    //self.rightLabel.text = @"20%";
    [self addSubview:self.rightLabel];

    _slider = [[UISlider alloc] init];
    _slider.value = 0.6;
    [self addSubview:_slider];
}


-(void)initConstraints
{
    self.rightLabel.translatesAutoresizingMaskIntoConstraints = NO;
    self.leftLabel.translatesAutoresizingMaskIntoConstraints = NO;
    self.slider.translatesAutoresizingMaskIntoConstraints = NO;

    id views = @{
                 @"leftLabel": self.leftLabel,
                 @"slider": self.slider,
                 @"rightLabel": self.rightLabel,
                 };
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[leftLabel(==90)]-5-[slider(==120)]-[rightLabel(==50)]-|" options:0 metrics:nil views:views]];


    [self addConstraint:[NSLayoutConstraint constraintWithItem:self.slider attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0]];
    [self addConstraint:[NSLayoutConstraint constraintWithItem:self.leftLabel attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0]];
    [self addConstraint:[NSLayoutConstraint constraintWithItem:self.rightLabel attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0]];
}
@end

2-然后，我创建了这个名为MultiSliderView的视图，它使用了先前的View（UnitSliderView）：

#import "MultiSliderView.h"  
#import "UnitSliderView.h"

static const int kUnitsCount = 3;

@implementation MultiSliderView

-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self != nil)
    {
        //initialization
        self.backgroundColor = [UIColor clearColor];
        [self initViews];
    }
    return self;
}

- (void)initViews {

    float totalHeight = self.frame.size.height;
    float spacingRatio = 0.1;
    float heightPerUnit = totalHeight/(kUnitsCount+spacingRatio*(kUnitsCount));

    for (int i = 0; i < kUnitsCount; i++)
    {
        double percentage = [self.dataSource valueForSliderAtIndex:i];
        NSString *leftString = [self.dataSource stringForLeftLabelAtIndex:i];
        NSString *rightString = [self.dataSource stringForRightLabelAtIndex:i];
        UnitSliderView *unit = [[UnitSliderView alloc] initWithFrame:CGRectMake(0, i*heightPerUnit + (i)*heightPerUnit*spacingRatio, self.frame.size.width, heightPerUnit)];
        unit.slider.value = percentage;
        unit.leftLabel.text = leftString;
        unit.rightLabel.text = rightString;
        [self addSubview:unit];
    }   
}    
@end

3 - 问题：当我在viewController中初始化MultiSlidersView时，我没有调用我在同一个视图控制器中实现的数据源方法，因此不显示标签和滑块值是0。

我认为我的某些代码不在正确的位置，但我无法以不同的方式找到它。

Answer 1

在调用init函数之前，您应该在之前定义已创建的类<em>的dataSource。您应该定义方法initWithFrame:(CGRect)frame andDataSource:(id <MultiSliderViewDataSource> ) dataSource并使用它来初始化您的视图。

Answer 2

我假设您希望在幻灯片值更改时调用操作。由于您在代码中实现了所有内容，因此可以使用以下代码在代码中执

[youSlider addTarget:self action:@selector(sliderValueChanged:) forControlEvents:UIControlEventValueChanged];

不为此自定义视图调用数据源的方法

2 个答案: