ios - 面对 UISwitch 打开/关闭的问题

Question

屏幕上有 6 个开关控件。一次只能启用一个开关。如果第 5 个开关打开，则一个标签和一个文本字段应该可见或者隐藏。

当 5 开关从关闭变为打开并再次变为关闭时，我遇到了问题。标签和提交的文本应该被隐藏，但它没有按要求工作。

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.sw_switch1.on = NO;
    self.sw_switch2.on = NO;
    self.sw_switch3.on = NO;
    self.sw_switch4.on = NO;
    self.sw_switch5.on = NO;
    self.sw_switch6.on = NO;

    lbl_desc.hidden = YES;
    txt_desc.hidden = YES;

}


-(IBAction)switchChange:(id)sender
{

        if(sw_switch1.isOn)
        {
            //self.sw_switch1.on = NO;
            self.sw_switch2.on = NO;
            self.sw_switch3.on = NO;
            self.sw_switch4.on = NO;
            self.sw_switch5.on = NO;
            self.sw_switch6.on = NO;

        }


        else if(sw_switch2.isOn)
        {
            self.sw_switch1.on = NO;
            //self.sw_switch2.on = NO;
            self.sw_switch3.on = NO;
            self.sw_switch4.on = NO;
            self.sw_switch5.on = NO;
            self.sw_switch6.on = NO;

        }


        else if(sw_switch3.isOn)
        {
            self.sw_switch1.on = NO;
            self.sw_switch2.on = NO;
            //self.sw_switch3.on = NO;
            self.sw_switch4.on = NO;
            self.sw_switch5.on = NO;
            self.sw_switch6.on = NO;

        }
        else if(sw_switch4.isOn)
        {
            self.sw_switch1.on = NO;
            self.sw_switch2.on = NO;
            self.sw_switch3.on = NO;
            //self.sw_switch4.on = NO;
            self.sw_switch5.on = NO;
            self.sw_switch6.on = NO;

        }

        else if(sw_switch5.isOn)
        {
            self.sw_switch1.on = NO;
            self.sw_switch2.on = NO;
            self.sw_switch3.on = NO;
            self.sw_switch4.on = NO;
            //self.sw_switch5.on = NO;
            self.sw_switch6.on = NO;
            lbl_desc.hidden = YES;
            txt_desc.hidden = YES;

        }

        else if(sw_switch6.isOn)
        {
            lbl_desc.hidden = NO;
            txt_desc.hidden = NO;
            self.sw_switch1.on = NO;
            self.sw_switch2.on = NO;
            self.sw_switch3.on = NO;
            self.sw_switch4.on = NO;
            self.sw_switch5.on = NO;
            //self.sw_switch6.on = NO;
        }


    [self viewWillAppear:NO];

}

Answer 1

当开关打开时，您隐藏标签 (.hidden = YES)。但是当其他人关闭时，您不会取消隐藏(.hidden = NO)。无论如何，您的代码有点不合逻辑。

我建议:

-(IBAction)switchChange:(id)sender
{

            UISwitch *theSwitch = (UISwitch *) sender; 
            BOOL switchState = theSwitch.on; //this method is called when changed to on or off. 

            self.sw_switch1.on = NO;  // force all switches off
            self.sw_switch2.on = NO;
            self.sw_switch3.on = NO;
            self.sw_switch4.on = NO;
            self.sw_switch5.on = NO;
            self.sw_switch6.on = NO;

            theSwitch.on = switchState; // recover the state set by the user. 

            //now hide or unhide the labels depending on the state of switch 5. 
            lbl_desc.hidden = self.sw_switch5.on;
            txt_desc.hidden = self.sw_switch5.on;

    // [self viewWillAppear:NO];   // What the h.... is this? You are not supposed to call that method. Use self.view.setNeedsDisplay or so instead.

    [self.view setNeedsDisplay];  // This may not be reqired but it forces the view to re-display itself. 

}