iPhone / xCode完成工具栏键盘附件类

Question

我正在尝试创建一个可以调用以轻松实现完成工具栏的类。

目前我这样称呼它，

    -(void)textFieldDidBeginEditing:(UITextField *)textField{
       DoneToolbar *tlbDone = [[DoneToolbar alloc] initWithFrame:CGRectMake(0,0,320,44)];
       [textField setInputAccessoryView:tlbDone];
    }

这可以调出工具栏，但问题是“完成”按钮，

目前我正在尝试通过以下代码执行此操作，

#import "DoneToolbar.h"

@implementation DoneToolbar
@synthesize btnDone;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        //Done Button
        UIBarButtonItem *doneBarButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(btnDonePressed)];
        UIBarButtonItem *flexible = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
        NSArray *barItemArr = [NSArray arrayWithObjects:flexible,doneBarButton, nil];
        self.items = barItemArr;
        [self.superview endEditing:YES];
    }
    return self;
}

- (void)btnDonePressed{
        [self.superview endEditing:YES];
}

@end

我做错了什么？