小编use*_*846的帖子

如何在视图上渲染阴影？我尝试过shadowColor,shadowOffset,shadowOpacity和shadowRadius的许多组合,它们似乎什么都不做.我确信样式正确应用,因为我设置的其他属性工作.

I'd like to create a text field which uses the number pad and accepts only numbers, even when pasted. Currently, I have a header as such:

#import <UIKit/UIKit.h>

@interface DRPNumberTextField : UITextField <UITextFieldDelegate>

@end

and an implementation:

#import "DRPNumberTextField.h"

@implementation DRPNumberTextField

- (id) initWithFrame:(CGRect)frame
{
  self = [super initWithFrame:frame];
  if (self)
  {
    self.delegate = self;
    [self setKeyboardType:UIKeyboardTypeNumberPad];
  }
  return self;
}

- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
  if ([string rangeOfCharacterFromSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]].location != NSNotFound)
  {
    return NO;
  } …