Question

请考虑以下代码：

这是我的价格计算器控制器头文件。

#import <Foundation/Foundation.h>
#import "PriceCalculator.h"

@interface PriceCalculatorController : UITextField {

    IBOutlet UITextField *mpgField;
    IBOutlet UITextField *milesField;
    IBOutlet UITextField *priceField;
    IBOutlet UITextField *ridersField;
    IBOutlet UITextField *splitField;

    PriceCalculator *calculator;
}


-(IBAction)calculator:(id)sender;

@end

以下是其实施文件：

#import "PriceCalculatorController.h"

@implementation PriceCalculatorController


- (IBAction)calculator:(id)sender {

    float split;

    calculator = [[PriceCalculator alloc]init];


    [calculator setMpg:[mpgField float]];
    [calculator setRiders: [ridersField float]];
    [calculator setMiles: [milesField float]];
    [calculator setPrice: [priceField float]];


    split = [calculator CalculateSplit];

    [splitField setFloatValue:split];
}
@end

它给了我错误：

receiver type 'UITextField' for instance message does not
declare a method with selector 'float' [4]

发生了什么事？

Answer 1

这可能对您有所帮助： http://www.iphonedevsdk.com/forum/iphone-sdk-development/87944-uitextview-calculation-not-working.html

Answer 2

您尝试在每个字段上调用方法float，并且没有方法float

也许你的意思是[mpgField.text floatValue];而已。

Answer 3

#import "PriceCalculatorController.h"

@implementation PriceCalculatorController


- (IBAction)calculator:(id)sender {

    float split;

    calculator = [[PriceCalculator alloc]init];


    [calculator setMpg:[mpgField.text floatValue]];
    [calculator setRiders: [ridersField.text floatValue]];
    [calculator setMiles: [milesField.text floatValue]];
    [calculator setPrice: [priceField.text floatValue]];


    split = [calculator CalculateSplit];

    [splitField setFloatValue:split];
}
@end

Answer 4

您使用的代码错误像这样改变方法

    [calculator setMpg:[mpgField floatValue]];
    [calculator setRiders: [ridersField floatValue]];
    [calculator setMiles: [milesField floatValue]];
    [calculator setPrice: [priceField floatValue]];

Answer 5

您需要首先将所有IBOulets定义为@property（nonretain，atomic）...然后合成它们。

然后您需要致电

[[fieldname text] floatValue]

在田野上。

编辑：

这是您想要的代码：

[calculator setMpg:[[mpgField text] floatValue]];
[calculator setRiders: [[ridersField text] floatValue]];
[calculator setMiles: [[milesField text] floatValue]];
[calculator setPrice: [[priceField text] floatValue]];

UITextView计算不起作用

5 个答案: