iphone - ios objective C Bool 未设置

Question

我正在创建自定义 UITextField，但没有设置 BOOL？？

MyCustomTextField.h

#import <UIKit/UIKit.h>

@interface OMTextField : UIControl <UITextFieldDelegate>

{
    UITextField *_theTextField;

    BOOL _hasBackGroundImage;
}

@property (nonatomic, retain)UITextField *theTextField;
@property (nonatomic) BOOL hasBackGroundImage;

@end

MyCustomTextField.m

#import "OMTextField.h"

@implementation OMTextField

@synthesize theTextField = _theTextField;
@synthesize hasBackGroundImage = _hasBackGroundImage;

- (void)dealloc 
{
    [_theTextField release];
    [super dealloc];
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code

        self.theTextField = [[[UITextField alloc]initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height)]autorelease];
        //self.theTextField.borderStyle = UITextBorderStyleLine;
        self.theTextField.text = @"textField";
        self.theTextField.delegate = self;

        if (self.hasBackGroundImage) {
            NSLog(@"lo tienes");
        }
    if (!self.hasBackGroundImage) {
        NSLog(@"nana tienes");
    }

        [self addSubview:self.theTextField];


    }
    return self;
}

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

@end

以及我的 MainVC 中的调用:

MyCustomTextField *textField = [[[MyCustomTextField alloc]initWithFrame:CGRectMake(400, 160, 150, 40)]autorelease];

    textField.hasBackGroundImage = YES;

    textField.backgroundColor = [UIColor grayColor];
    textField.theTextField.borderStyle = UITextBorderStyleLine;


    [self.view addSubview:textField];

所以它显示正常， 但正如您所见，我正在设置 textField.hasBackGroundImage = YES;

但是在执行时，我看到了 BOOL = NO 的消息？？

nana tienes

那么我错过了什么？，为什么这不被评估为是？？

谢谢!

Answer 1

您已将 NSLog 放在 initWithFrame 方法中。这是在设置 textField.hasBackGroundImage 之前的行上调用的，此时值仍然是 NO。

如果您希望看到设置此值，请将以下方法添加到 MyCustomTextField:

- (void)setHasBackGroundImage:(BOOL)flag
{
    _hasBackGroundImage = flag;
}

然后在这个方法上打断点。您应该会在设置后立即看到它。