Question

我有一个我要封装的自定义UIPicker，所以我可以重用它。我想要暴露的唯一事情就是委托协议，该协议将使用Subclassed UIPicker告诉ViewController更改了规模。

这是它在底部应该是什么样子以及它在顶部的样子。

enter image description here

这是我在图片中移动顶部选择器时记录的崩溃信息：

*** Assertion failure in -[UITableViewRowData rectForRow:inSection:], /SourceCache/UIKit_Sim/UIKit-2380.17/UITableViewRowData.m:1630

这是封装类的代码。我还没有想出我要编写的委托协议，但我想处理封装类中的UIPickerView dataSource和委托协议。这样我需要做的就是重用它，实现自定义委托协议，它告诉我规模已经改变了。

此代码与viewController一起用作UIPickerView的dataSource和委托。我正在努力学习如何制作可重复使用的对象。

#import "SWScalePickerView.h"
@interface SWScalePickerView()<UIPickerViewDataSource,UIPickerViewDelegate>

@property(nonatomic,retain)NSArray *fractions;
@property(nonatomic,retain)NSDecimalNumber *integer;
@property(nonatomic,retain)NSDecimalNumber *fraction;
@property(nonatomic,retain)NSDecimalNumber *scale;

@end

@implementation SWScalePickerView

@synthesize fractions = fractions_;
@synthesize fraction = fraction_;
@synthesize integer = integer_;
@synthesize scale = scale_;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        [self setDataSource:self];
        [self setDelegate:self];
    }
    return self;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
}
*/

#pragma mark - UIPicker

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 2;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    switch (component) {
        case 0:
            return 10;
            break;
        case 1:
            return [fractions_ count];
            break;
        default:
            break;
    }

    return 2;
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    switch (component) {
        case 0:
            return [NSString stringWithFormat:@"%d",row];
            break;
        case 1:
        {

            //return [NSString stringWithFormat:@"%d",row];
            return [fractions_ objectAtIndex:row];
        }
            break;
        default:
            break;
    }
    return @"Fix Something";
}

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component
{
    return 55.0;
}


- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{


    switch (component) {
        case 0:
            integer_ = [NSDecimalNumber decimalNumberWithString:[NSString stringWithFormat:@"%d",row]];
            break;
        case 1:
        {
            NSString *string = [fractions_ objectAtIndex:row];
            if ([string isEqualToString:@"--"]) {
                fraction_ = [NSDecimalNumber zero];
            }
            if ([string isEqualToString:@"1/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.125"];
            }
            if ([string isEqualToString:@"1/4"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.25"];
            }
            if ([string isEqualToString:@"1/3"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.33"];
            }
            if ([string isEqualToString:@"3/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.375"];
            }
            if ([string isEqualToString:@"1/2"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.5"];
            }
            if ([string isEqualToString:@"5/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.625"];
            }
            if ([string isEqualToString:@"2/3"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.666"];
            }
            if ([string isEqualToString:@"7/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.875"];
            }
        }
            break;
    }
    scale_ = [NSDecimalNumber zero];
    scale_ = [integer_ decimalNumberByAdding:fraction_];
    NSLog(@"%@",[scale_ stringValue]);

    //[scaleButton_ setTitle:[scale_ stringValue] forState:UIControlStateNormal];

    return;
}

Answer 1

这是解决方案。因为我正在使用接口构建器，所以我必须在initWithCoder方法中初始化dataSource和委托，而不是initWithFrame。这解决了第一个错误。

要使此自定义选择器将比例返回到正在使用它的viewController，您可以使viewController符合协议。然后在自定义类中的didSelectRow委托方法中，调用视图控制器要实现的方法。它现在被称为“dancePuppets”。那是Bel Air的新鲜王子笑话。这就是你可以返回比例的地方。

#import <UIKit/UIKit.h>

@protocol SWScalePickerDelegate <NSObject>

-(void)dancePuppets;    //Method that 

@end

@interface SWScalePickerView : UIPickerView
{
    IBOutlet id<SWScalePickerDelegate> client;
}

@end

#import "SWScalePickerView.h"
@interface SWScalePickerView()<UIPickerViewDataSource,UIPickerViewDelegate>

@property(nonatomic,retain)NSArray *fractions;
@property(nonatomic,retain)NSDecimalNumber *integer;
@property(nonatomic,retain)NSDecimalNumber *fraction;
@property(nonatomic,retain)NSDecimalNumber *scale;

@end

@implementation SWScalePickerView

@synthesize fractions = fractions_;
@synthesize fraction = fraction_;
@synthesize integer = integer_;
@synthesize scale = scale_;

- (id)initWithCoder:(NSCoder *)decoder {
    if ((self = [super initWithCoder:decoder])) {
        [self setDataSource:self];
        [self setDelegate:self];
        fractions_ = [[NSArray alloc]initWithObjects:@"--",@"1/8",@"1/4",@"1/3",@"3/8",@"1/2",@"5/8",@"2/3",@"7/8",nil];
        integer_ = [NSDecimalNumber zero];
        fraction_ = [NSDecimalNumber zero];
        //[picker_ selectedRowInComponent:1]
        [self selectRow:1 inComponent:0 animated:YES];
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        [self setDataSource:self];
        [self setDelegate:self];
        fractions_ = [[NSArray alloc]initWithObjects:@"--",@"1/8",@"1/4",@"1/3",@"3/8",@"1/2",@"5/8",@"2/3",@"7/8",nil];
        integer_ = [NSDecimalNumber zero];
        fraction_ = [NSDecimalNumber zero];
        //[picker_ selectedRowInComponent:1]
        [self selectRow:1 inComponent:0 animated:YES];
    }
    return self;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
}
*/

#pragma mark - UIPicker

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 2;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    switch (component) {
        case 0:
            return 10;
            break;
        case 1:
            return [fractions_ count];
            break;
        default:
            break;
    }

    return 2;
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    switch (component) {
        case 0:
            return [NSString stringWithFormat:@"%d",row];
            break;
        case 1:
        {

            //return [NSString stringWithFormat:@"%d",row];
            return [fractions_ objectAtIndex:row];
        }
            break;
        default:
            break;
    }
    return @"Fix Something";
}

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component
{
    return 55.0;
}


- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{


    switch (component)
    {
        case 0:
            integer_ = [NSDecimalNumber decimalNumberWithString:[NSString stringWithFormat:@"%d",row]];
            break;
        case 1:
        {
            NSString *string = [fractions_ objectAtIndex:row];
            if ([string isEqualToString:@"--"]) {
                fraction_ = [NSDecimalNumber zero];
            }
            if ([string isEqualToString:@"1/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.125"];
            }
            if ([string isEqualToString:@"1/4"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.25"];
            }
            if ([string isEqualToString:@"1/3"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.33"];
            }
            if ([string isEqualToString:@"3/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.375"];
            }
            if ([string isEqualToString:@"1/2"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.5"];
            }
            if ([string isEqualToString:@"5/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.625"];
            }
            if ([string isEqualToString:@"2/3"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.666"];
            }
            if ([string isEqualToString:@"7/8"]) {
                fraction_ = [NSDecimalNumber decimalNumberWithString:@"0.875"];
            }
        }
            break;
    }
    scale_ = [NSDecimalNumber zero];
    scale_ = [integer_ decimalNumberByAdding:fraction_];
    NSLog(@"Set Scale to: %@",[scale_ stringValue]);

    [client dancePuppets];

    //[scaleButton_ setTitle:[scale_ stringValue] forState:UIControlStateNormal];

    return;
}


@end

如何封装自定义UIPicker？

1 个答案: