自定义软键盘上的Return键的文本

#import <UIKit/UIKit.h>

typedef void(^DoneActionBlock)(id);

@interface CustomeTextField : UITextField


@property(nonatomic,retain) UIButton* doneButton;
@property(nonatomic,retain) NSString* buttonTitle;
@property(nonatomic,copy)   DoneActionBlock doneEven;

@end

#import "CustomeTextField.h"

@implementation CustomeTextField


@synthesize doneButton,buttonTitle,doneEven;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        // 注册UIKeyboardDidShowNotification通知的观察者为self
        
        [[NSNotificationCenter defaultCenter] addObserver:self
         
                                                 selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
        
        [[NSNotificationCenter defaultCenter] addObserver:self
         
                                                 selector:@selector(keyboardDidHide:)
         
                                                     name:UIKeyboardDidHideNotification  object:nil];
    }
    return self;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
}
*/


// 实现观察者的注册事件

-(void)keyboardDidHide:(NSNotification*)note{
    
    if (self.doneButton) {
        
        self.doneButton.hidden=YES;
        
    }
    
}



- (void)keyboardDidShow:(NSNotification *)note {
    
    UIWindow* tempWindow = nil;
    UIView* keyboard = nil;
    
    tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
    
    if (tempWindow == nil)
    {
        return;
    }
    
    int viewCount = [tempWindow.subviews count];
    
    ////find key board view.
    for(int i=0; i<viewCount; i++)
    {
        keyboard = [tempWindow.subviews objectAtIndex:i];
        
        //keyboard view found; add the custom button to it
        if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2)
        {
            if(([[keyboard description] hasPrefix:@"<UIPeripheralHostView"] == YES) ||(([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)))
            {
                NSLog(@"find UIKeyboard or UIPeripheralHostView");
                [self creatDoneButton];
                [keyboard addSubview:doneButton];
                break;
            }
        }
        else
        {
            if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)
            {
                NSLog(@"find UIKeyboard");
                break;
            }
        }
    }
    
}

-(void)creatDoneButton
{
    // 在键盘第1次弹出时，创建按钮
    
    if (self.doneButton == nil) {
        
        self.doneButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        
        self.doneButton.hidden=YES;
        
        //定制按钮上面要显示的文字，也可以在创建该对象时自定义，本文只自定义了按钮上面的显示文字为：buttonTitle
        
        [self.doneButton setTitle:buttonTitle forState:UIControlStateNormal];   // 设置按钮的位置在恰当的地方
        
        [self.doneButton setFrame:CGRectMake(773/2.0, 250/2.0, 180/2.0, 68/2.0)];
        
        [self.doneButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        
        self.doneButton.titleLabel.font = [UIFont systemFontOfSize:16];
        
        [self.doneButton setTitle:@"hello" forState:UIControlStateNormal];
        
        // 设置按钮背景图片
        
        [self.doneButton setBackgroundImage:[UIImage imageNamed:@"music_starHead_1.png"] forState:UIControlStateNormal];
        
        // 当按钮按下时，触发doneButton方法
        
        [self.doneButton addTarget:self action:@selector(doneButton:)  forControlEvents:UIControlEventTouchUpInside];
        
    }
    
    if (self.editing) {  // 只有当前输入框会显示done按钮
        
        self.doneButton.hidden = NO;
        
    } else {
        
        self.doneButton.hidden = YES;
        
    }
}

//定制按钮的点击事件

- (void)doneButton:(id)sender {
    
    
    
    self.doneButton.hidden=YES;
    
    [self resignFirstResponder];
    
    if (doneEven!=nil) {  // block 回调
        
        doneEven(sender);
        
    }
    
}

- (void)dealloc

{
    
    self.doneButton = nil;
    
    self.doneEven = nil;
    
    self.buttonTitle = nil;
    
    
    
    [super dealloc];
    
}

@end

参考   http://www.cocoachina.com/bbs/read.php?tid=14886&page=1