UIKeyboardTypeDecimalPad - 将逗号更改为点 [英] UIKeyboardTypeDecimalPad - change comma to dot

问题描述

我使用此方法显示带小数分隔符的键盘

I use this method to show keyboard with decimal separator

myTextField.keyboardType=UIKeyboardTypeDecimalPad;

如何将逗号更改为点分隔符？

How can I change comma to dot separator?

我有一个芬兰语语言环境。使用逗号，小数在我的应用程序上不起作用。

I have a Finnish locale. With comma, decimals doesn't work on my app.

-(IBAction)calculate {
    float x = ([paino.text floatValue]) / ([pituus.text floatValue]) *10000;    
    label.text = [[NSString alloc] initWithFormat:@"%0.02f", x];
}

推荐答案

好的，所以你可以编辑一个文本字段使用数字键盘，它取决于当前的语言环境，从而得到一个数字的文本表示，该数字也依赖于当前语言环境。编辑完成后，您阅读它并想要转换为数字。

OK so you edit a text field using a numeric keyboard, which is dependent on the current locale, and thus get a text representation of a number, which is dependendt on the current locale, too. After editing has finished you read it and want to transform into a number.

要转换你会像这样使用NSNumberFormatter：

To convert you would use NSNumberFormatter like this:

NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];

您可以设置格式化程序，设置区域设置（！），限制，格式化，小数/分组分隔符，小数位数等等。然后你只需使用它：

You can setup the formatter as you will, setting locale (!), limits, formatting, decimal/grouping separator, number of decimal digits etc. Then you just use it:

float number = [nf numberFromString: field.text];

这就是全部！现在你有了这个数字，即使文本中包含逗号，只要你让：keyboard和formatter都具有相同的格式，相同的样式 - 也就是说只需让当前的语言环境可以在整个地方使用。

And that's all! Now you have the number even if the text includes comma, provided you let both: keyboard and formatter, to have the same format, same style - i.e. probably just let current locale be used all over the place.

编辑

这是一种货币格式化程序，可以在货币的字符串和数字之间进行转换：

this is a currency formatter, that can convert between string and number for currencies:

NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[nf setNumberStyle: NSNumberFormatterCurrencyStyle];
[nf setRoundingMode: NSNumberFormatterRoundHalfUp];
[nf setMaximumFractionDigits: 2]

这是一个带有4位小数的百分比格式化程序：

this is a percentage formatter with 4 decimal places:

NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
[nf setNumberStyle: NSNumberFormatterPercentStyle];
[nf setRoundingMode: NSNumberFormatterRoundHalfUp];
[nf setMaximumFractionDigits: 4];

当前区域设置。

如您所见，您可以根据您尝试输入的数字来定义样式，数字，舍入行为等等。有关更多细节（你可以用NSNumberFormatter做很多事情）你应该阅读Apple文档，它将超出SO答案的范围来描述它。

As you see you can define the style, digits, rounding behaviour and much more, depending on numbers you are trying to enter. For more details (it is really a lot you can do with the NSNumberFormatter) you should read Apple docs, it would go beyond the scope of SO answer to describe it all.

在你的情况下，如果paino和pituus也是UITextFields：

In your case, provided that paino and pituus are also UITextFields:

-(IBAction)calculate {
    NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
    [nf setRoundingMode: NSNumberFormatterRoundHalfUp];
    [nf setMaximumFractionDigits: 2];

    float npaino = [[nf numberFromString: paino.text] floatValue];
    float npituus = [[nf numberFromString: pituus.text] floatValue];

    float x = npaino] / npituus *10000;    
    label.text = [nf stringFromNumber: [NSNumber numberWithFloat: x]];

    [nf release];
}

现在为了避免在每次计算中创建格式化程序，可以将其设为实例变量，因为这些转换只需要一个。

Now to avoid creating the formatter in each calculation you could make it an instance variable, since you need only one for those conversions.

这篇关于UIKeyboardTypeDecimalPad - 将逗号更改为点的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！