iphone - Objective C iPhone 子类化 UITextField catch 值已更改

Question

我已经对 UITextField 进行了子类化，因此我可以为其创建一些自定义行为。这是我的类(class):

DataboundTextField.h

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#import "TestEntities.h"

@interface DataboundTextField : UITextField <UITextFieldDelegate> {
NSString *valueMember;
NSString *displayValueMember;
ODataObject *boundEntity;

}
@property (nonatomic, retain) NSString *valueMember;
@property (nonatomic, retain) NSString *displayValueMember;
@property (nonatomic, retain) ODataObject *boundEntity;
-(void)SetupDataBinding:(ODataObject*)oDataEntity ValueMember:(NSString*)valMemberID    DisplayValueMember:(NSString*)disValMember;

@end

DataboundTextField.m

#import "DataboundTextField.h"

@implementation DataboundTextField

@synthesize valueMember;
@synthesize displayValueMember;
@synthesize boundEntity;

-(id) initWithCoder:(NSCoder *)aDecoder{
if ((self = [super initWithCoder:aDecoder]))
{
    self.delegate = self;
}

return self;
}



-(void)SetupDataBinding:(ODataObject*)oDataEntity ValueMember:(NSString*)valMemberID DisplayValueMember:(NSString*)disValMember{

}

-(BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
return YES;
}

@end

如何覆盖 ValueChanged 事件？无论我如何努力，我似乎​​都无法捕获它。我想做的就是在 View 上添加这些子类文本字段之一并捕获该事件并处理它。

请帮忙。

提前致谢

Answer 1

根据UITextFieldDelegate的文档，您可以使用

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)范围 replacementString:(NSString *)string

The text field calls this method whenever the user types a new character in the text field or deletes an existing character.

确保设置 UITextField 的 delegate 属性:

- (id)init
{
    if ((self = [super init]))
    {
        self.delegate = self;
    }
}