ios - 此自定义 View 不调用数据源的方法

Question

我想实现这样的事情:

1-首先，我实现了这个 View :UnitSliderView:

使用这段代码:

#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 View ，名为 MultiSliderView，它使用先前的 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，不会调用我在同一 View Controller 中实现的数据源方法，因此不会显示标签和 slider 值为 0。

我认为我的一些代码不在正确的位置，但我找不到不同的方法。

Answer 1

您应该在调用 init 函数之前定义所创建类的数据源。你应该定义一个方法 initWithFrame:(CGRect)frame andDataSource:(id <MultiSliderViewDataSource> ) dataSource并使用它来初始化您的 View 。