如何在單擊同一UIbutton的同時更改UIButton backgroundimage？

Question

我在xib backgroundImage是check_box_off.png的情況下使用UIButton ，同時單擊atmbtn backgroundImage更改為check_box_on.png，同時NSLog打印yesString ，再次單擊atmbtn，backgroundImage相同check_box_on.png不變，而NSLog僅打印相同的yesString 。再次叮當響atmbutton一樣只發生..

- (IBAction)atmAction:(id)sender{  
    if( [atmbtn backgroundImageForState:UIControlStateNormal] ==
        [UIImage imageNamed:@"check_box_on.png"] ) {
       [atmbtn setImage:[UIImage imageNamed:@"check_box_off.png"] 
               forState:UIControlStateNormal]; 

        noString = @"No"; 
        NSLog(@"atm=%@",noString);
    } else if( [atmbtn backgroundImageForState:UIControlStateNormal] ==
                [UIImage imageNamed:@"check_box_off.png"]) {

        [atmbtn setImage:[UIImage imageNamed:@"check_box_on.png"]
                forState:UIControlStateNormal];

         yesString = @"Yes";
         NSLog(@"atm = %@",yesString);
     }
}

輸出：

NSLog打印：

atm =是

atm =是

atm =是

我該如何解決？ 請分享您的想法。

Answer 1

用這個：

[atmbtn setBackgroundImage:[UIImage imageNamed:@"check_box_on.png"] forState:UIControlStateNormal];

Answer 2

設置一個BOOL變量而不是if條件

.h文件

BOOL _isClicked;

.m文件

-(IBAction)atmAction:(id)sender{  

    if(!isClicked){

       [atmbtn setImage:[UIImage imageNamed:@"check_box_off.png"]
               forState:UIControlStateNormal];   
        _isClicked = YES;      

     } else {

         [atmbtn setImage:[UIImage imageNamed:@"check_box_on.png"]
                 forState:UIControlStateNormal];    
          _isClicked = NO;
     }
}

Answer 3

您正在設置UIImage並且正在檢查backgroundImage 。

嘗試

if([atmbtn imageForState:UIControlStateNormal] ==
   [UIImage imageNamed:@"check_box_on.png"])

代替

if([atmbtn backgroundImageForState:UIControlStateNormal] ==
   [UIImage imageNamed:@"check_box_on.png"])

Answer 4

您可以簡單地使用

    [atmbtn setBackgroundImage:[UIImage imageNamed:@"check_box_off.png"]
                    forState:UIControlStateNormal];
    [atmbtn setBackgroundImage:[UIImage imageNamed:@"check_box_on.png"]
                    forState:UIControlStateSelected];

其中atmbtn是atmbtn中按鈕的插座。

Answer 5

嗨，嘗試isEqual方法而不是==因為您是在比較對象而不是值。 嘗試這個：

-(IBAction)atmAction:(id)sender{

    if([[atmbtn imageForState:UIControlStateNormal] 
          isEqual:[UIImage imageNamed:@"check_box_on.png"]] ) {

        [atmbtn setImage:[UIImage imageNamed:@"check_box_off.png"]
                forState:UIControlStateNormal];
        noString = @"No";
        NSLog(@"atm = %@",noString);

    } else if( [[atmbtn imageForState:UIControlStateNormal] 
                  isEqual:[UIImage imageNamed:@"check_box_off.png"]] ){

        [atmbtn setImage:[UIImage imageNamed:@"check_box_on.png"]
                forState:UIControlStateNormal];

        yesString = @"Yes";
        NSLog(@"atm = %@",yesString);
    }
}