Question

我为iOS8应用编写了以下代码：

     UIButton *btnBack = [UIButton buttonWithType:UIButtonTypeCustom];
    [btnBack setFrame:CGRectMake(40, 30, 30, 30)];
    [btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close.png"]forState:UIControlStateNormal];
    [btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close_on.png"] forState:UIControlStateHighlighted|UIControlStateSelected];
    [btnBack addTarget:self action:@selector(btnBackClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btnBack];

点击时的方法：

-(void) btnBackClick:(id)sender{
[self.navigationController popToRootViewControllerAnimated:YES];
}

但是，单击按钮时图像的背景不会改变。唯一的影响是灰色。

如果我在xib文件上绘制该按钮，则图像更改就像魅力一样。

有什么不对吗？请帮忙。

Answer 1

-(void) btnBackClick:(id)sender{
   UIButton *myButton = (UIButton *)sender;

   [myButton setSelected: YES]; // Add this line
   [self.navigationController popToRootViewControllerAnimated:YES];
 }

同样在viewWillAppear方法中设置与NO

相同

[myButton setSelected: NO]; // Add this line

Answer 2

UIButton *btnBack = [UIButton buttonWithType:UIButtonTypeCustom];
[btnBack setFrame:CGRectMake(40, 30, 30, 30)];
[btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close.png"]forState:UIControlStateNormal];
[btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close_on.png"] forState:UIControlStateHighlighted|UIControlStateSelected];
[btnBack addTarget:self action:@selector(btnBackClick:) forControlEvents:UIControlEventTouchUpInside];
[btnBack setSelected:YES];
[self.view addSubview:btnBack];

// ********** *******更新

UIButton *btnBack = [UIButton buttonWithType:UIButtonTypeCustom];
[btnBack setFrame:CGRectMake(40, 30, 30, 30)];
[btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close.png"]forState:UIControlStateNormal];
[btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close_on.png"] forState:UIControlStateHighlighted];
[btnBack setBackgroundImage:[UIImage imageNamed:@"btn_close_on.png"] forState:UIControlStateSelected];
[btnBack addTarget:self action:@selector(btnBackClick:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btnBack];

-(void)btnBackClick:(UIButton *)btn
{
    if ([btn isSelected])
    {
        [btn setSelected:NO];
    }
    else
        [btn setSelected:YES];
}

UHTutton图像在Hightlight或Selected状态下未更改

2 个答案: