今天项目中有个文本框需要只可以输入数字的需求，首先在.xib中将UITextField的Keyboard设置为Number Pad，但是使用时键盘会切回别的键盘无法对内容进行校验。通过神奇的百度我知道了通过以下方法可以解决这样的问题：
首先让.xib的viewController实现UITextFieldDelegate然后和想要校验的控件关联。
然后将下列代码粘贴到类中即可。
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {return [self validateNumber:string];
}- (BOOL)validateNumber:(NSString*)number {BOOL res = YES;NSCharacterSet* tmpSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];int i = 0;while (i < number.length) {NSString * string = [number substringWithRange:NSMakeRange(i, 1)];NSRange range = [string rangeOfCharacterFromSet:tmpSet];if (range.length == 0) {res = NO;break;}i++;}return res;
}
还有一种方式，以下这种方式我还没有试过但是我找到了就分享出来吧：
1.定义常量以备使用
#define NUMBERS @"0123456789"
- (BOOL)textField:(UITextField*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string
{NSCharacterSet*cs;cs = [[NSCharacterSetcharacterSetWithCharactersInString:NUMBERS] invertedSet];NSString*filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];BOOLbasicTest = [string isEqualToString:filtered];if(!basicTest) {UIAlertView* alert = [[UIAlertViewalloc] initWithTitle:@"提示"message:@"请输入数字"delegate:nilcancelButtonTitle:@"确定"otherButtonTitles:nil];[alert show];returnNO;}returnYES;
}
