ios 7 带小数点的计算器应用程序

Question

好的，这是我的代码

它现在将用户输入限制为小数点后的两个字符并检查小数点，但现在它不再允许我加减...... /sigh

//
//  CalculatorViewController.h
//  
//


#import "ViewController.h"

int Method;
long int SelectNumber;
float RunningTotal;


@interface CalculatorViewController : ViewController <UITextFieldDelegate>

@property (strong, nonatomic) IBOutlet UILabel *screen;

- (IBAction)backToMainViewFromCalculatorViewButton:(id)sender;


@end

还有我的.m

//
//  CalculatorViewController.m
//  
//


#import "CalculatorViewController.h"
BOOL isDecimal;
float resultNumber;
float displayNumber;
int operation;

NSUInteger decimalPlacesLimit = 2;


@interface CalculatorViewController ()

@end

@implementation CalculatorViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

//    self.screen.text = @"";
    isDecimal = false;
    resultNumber = 0;
    self.screen.adjustsFontSizeToFitWidth = TRUE;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

- (IBAction)backToMainViewFromCalculatorViewButton:(id)sender {

    // Dismiss the VIEW
    // DO NOT SEGUE back
    // DO THIS
    //Going back using segue just stacks views and then soon you run out of memory and APP crashes
    [self dismissViewControllerAnimated:YES completion:NULL];
}

-(void)setResultWithNumber:(int)theNumber{

    if(!isDecimal){
        displayNumber *= 10;
        displayNumber += theNumber;
        self.screen.text = [NSString stringWithFormat:@"%.0f", displayNumber];
    }
    else
    {
        self.screen.text = [self.screen.text stringByAppendingString:[NSString stringWithFormat:@"%d", theNumber]];
    }
    displayNumber = [self.screen.text floatValue];
}

-(void)operationWithNumber:(int)theNumber{

    isDecimal = false;

    if(resultNumber == 0){
        resultNumber = displayNumber;
    }
    else{
        self.screen.text = [NSString stringWithFormat:@"%.2f",resultNumber];
        switch (operation) {
            case 1:
                resultNumber += displayNumber;
                break;
            case 2:
                resultNumber -= displayNumber;
                break;
            case 3:
                resultNumber = displayNumber*resultNumber;
                break;
            case 4:
                resultNumber /= displayNumber;
                break;

            default:
                break;
        }
    }
    operation = theNumber;
    displayNumber = 0;

}
- (IBAction)AC:(id)sender {
    operation = 0;
    resultNumber = 0;
    displayNumber = 0;
    isDecimal = false;
    self.screen.text = [NSString stringWithFormat:@"%i",0];

}
/*
- (IBAction)plus_minus:(id)sender {

    displayNumber = 0 - displayNumber;
    if(isDecimal)
        result.text = [NSString stringWithFormat:@"%.2f", displayNumber];
    else
        result.text = [NSString stringWithFormat:@"%.0f", displayNumber];

}

- (IBAction)divide:(id)sender {
    if(resultNumber != 0){
        [self operationWithNumber:operation];
        result.text = [NSString stringWithFormat:@"%.2f",resultNumber];
        displayNumber = [result.text floatValue];
        resultNumber = 0;
    }
    [self operationWithNumber:4];


}
 */
- (IBAction)seven:(id)sender
{
       NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:7];
        isDecimal = false;
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
            isDecimal = true;

        }
        else
        {
            isDecimal = false;
            [self setResultWithNumber:7];
        }
    }
}
- (IBAction)eight:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:8];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
             isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:8];
        }
    }
}
- (IBAction)nine:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:9];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
              isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:9];
        }
    }
}
/*
- (IBAction)multiply:(id)sender {
    if(resultNumber != 0){
        [self operationWithNumber:operation];
        result.text = [NSString stringWithFormat:@"%.2f",resultNumber];
        displayNumber = [result.text floatValue];
        resultNumber = 0;
    }
    [self operationWithNumber:3];
}
 */
- (IBAction)six:(id)sender
{
       NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:6];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
            isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:6];
        }
    }
}
- (IBAction)five:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:5];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
              isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:5];
        }
    }
}
- (IBAction)four:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:4];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
              isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:4];
        }
    }
}
- (IBAction)substract:(id)sender {
    if(resultNumber != 0){
        [self operationWithNumber:operation];
        self.screen.text = [NSString stringWithFormat:@"%.2f",resultNumber];
        displayNumber = [self.screen.text floatValue];
        resultNumber = 0;
    }
    [self operationWithNumber:2];

}
- (IBAction)three:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:3];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
              isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:3];
        }
    }
}

- (IBAction)two:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        [self setResultWithNumber:2];
    }
    else
    {
        // If we allready ahve a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
             isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:2];
        }
    }
}
- (IBAction)one:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    if (range.location == NSNotFound)
    {
        // No period found
        isDecimal = false;
        // set the number
        [self setResultWithNumber:1];
    }
    else
    {
        // If we allready have a character move on to test for .
        NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
        NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
             isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:1];
        }
    }}


- (IBAction)add:(id)sender {
    if(resultNumber != 0)
    {
        [self operationWithNumber:operation];
        self.screen.text = [NSString stringWithFormat:@"%.2f",resultNumber];
        displayNumber = [self.screen.text floatValue];
        resultNumber = 0;
    }
[self operationWithNumber:1];
}

- (IBAction)zero:(id)sender
{

    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
       [self setResultWithNumber:0];
    }
    else
    {
     // If we allready ahve a character move on to test for .
     NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
     NSString *decimalPart = explodedString[1];

        if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
        {
            NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
             isDecimal = true;
        }
        else
        {
            [self setResultWithNumber:0];
        }
    }
}


- (IBAction)dot:(id)sender {

    isDecimal = true;
    NSRange range = [self.screen.text rangeOfString:@"."];

    // Search for a Period
    // If not found append one to the text
    if (range.location == NSNotFound)
    {
        self.screen.text = [self.screen.text stringByAppendingString:@"."];
    }
    // We must have a period so now lets test for how many places after the decimal
    // and limit it to two



 //   NSLog(@"text on the way: %@", string);


    /*
    NSUInteger decimalPlacesLimit = 2;

    NSRange rangeDot = [self.screen.text rangeOfString:@"." options:NSCaseInsensitiveSearch];
    NSRange rangeComma = [self.screen.text rangeOfString:@"," options:NSCaseInsensitiveSearch];
    if (rangeDot.length > 0 || rangeComma.length > 0)
    {
        if([self.screen.text isEqualToString:@"."])
        {
            NSLog(@"textField already contains a separator");
        }
        else
        {
            NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
            NSString *decimalPart = explodedString[1];

            if (decimalPart.length >= decimalPlacesLimit && ![self.screen.text isEqualToString:@""])
            {
                NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
            }
        }
    }
     */
}




- (IBAction)equals:(id)sender {
    [self operationWithNumber:operation];
    self.screen.text = [NSString stringWithFormat:@"%.2f",resultNumber];
    displayNumber = [self.screen.text floatValue];
    resultNumber = 0;

}



- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSLog(@"text on the way: %@", string);
    NSUInteger decimalPlacesLimit = 2;

    NSRange rangeDot = [textField.text rangeOfString:@"." options:NSCaseInsensitiveSearch];
    NSRange rangeComma = [textField.text rangeOfString:@"," options:NSCaseInsensitiveSearch];
    if (rangeDot.length > 0 || rangeComma.length > 0){
        if([string isEqualToString:@"."]) {
            NSLog(@"textField already contains a separator");
            return NO;
        } else {
            NSArray *explodedString = [textField.text componentsSeparatedByString:@"."];
            NSString *decimalPart = explodedString[1];
            if (decimalPart.length >= decimalPlacesLimit && ![string isEqualToString:@""]) {
                NSLog(@"textField already contains %lu decimal places", (unsigned long)decimalPlacesLimit);
                return NO;
            }
        }
    }

    return YES;
}

@end

我不知道如何确保我检查小数点，然后将条目限制在小数点后不超过两位，但仍然能够计算

任何帮助将不胜感激

特拉维斯

Answer 1

我之前构建了一个计算器应用程序。我所做的是：
使用标签来标识不同的按钮，0 代表按钮 0，1 代表按钮 1 ...，99 代表按钮点。所有这些按钮都触发了相同的IBAction 函数，在此函数中，只需通过应用您在上面创建的规则来检查用户按下的按钮是否可以添加到Label（您可以在这里使用 UILabel 而不是 UITextField）。 试试这个代码：

// Assume that, the number buttons have tags from 0 - 9 respectively, and dot button has tag 99
- (IBAction)onButtonPressed:(UIButton *)sender
{
    NSRange range = [self.screen.text rangeOfString:@"."];

    BOOL canUpdateScreen = YES;
    if(range.location != NSNotFound) {
        if(sender.tag == 99) {
            // Already got dot, cannot show another dot
            canUpdateScreen = NO;
        } else {
            NSArray *explodedString = [self.screen.text componentsSeparatedByString:@"."];
            if(explodedString[1].length >= decimalPlacesLimit) {
                canUpdateScreen = NO;
            }
        }
    }

    if(canUpdateScreen) {
        if(sender.tag == 99) {
            self.screen.text = [NSString stringWithFormat:@"%@%@", self.screen.text, @"."];
        } else {
            self.screen.text = [NSString stringWithFormat:@"%@%d", self.screen.text, sender.tag];
        }
    }
}

Answer 2

这里

-(IBAction)NUmber1:(id)sender{

    SelectNumber = SelectNumber * 10;
    SelectNumber = SelectNumber + 1;
    Screen.text = [NSString stringWithFormat:@"%i", SelectNumber];
}
you are erasing your current string with new INTEGER value. Try to change to

-(IBAction)NUmber1:(id)sender{
    Screen.text = [Screen.text stringByAppendingString:@"1"];
}

您还需要更改 SelectNumber 计算逻辑。我建议你在真正需要的时候从字符串中获取它

double SelectNumber = [Screen.text doubleValue];

Answer 3

问题，

您发布的代码是，UITextFieldDelegate 方法实现。如果您通过代码更新 UITextField 文本，则不会触发。

解决方案

您可以使用以下任何一种解决方案。

为了简化任务，您可以使用标记 0 到 9 来表示按钮 0 到 9，并使用其他值来表示“。”和“，”在另一个答案中提到。

// 1. Call the method (in your code) on tapping the buttons (0 - 9 and “.”) and conditionally update the UITextField.text (yourTextField.text), like

    update = [self textField:yourTextField shouldChangeCharactersInRange:NSMakeRange(yourTextField.text.length, 1) replacementString:yourButtonLabel];

    if (update)
    {
        // Uodate yourTextField
    }
    else
    {
        // Don’t update yourTextField
    }

// 2. Before updating yourTextField.text, check there is any decimal point or comma already in yourTextField, using

    if([yourTextField.text rangeOfString:@"."].location != NSNotFound) // Update condition to check comma if the tapped button is so
    {
        // Don’t update yourTextField
    }
    else
    {
        // Update yourTextField
    }