如果条件转换为switch语句,如何更改？

Question

我试图将以下代码从if语句更改为switch语句,但我得到一个错误,说我需要一个整数而不是id对象.

这是我的开关:

-(void) nearestIndexAfterRotationEnded:(int)index {
NSLog(@"Selected item is: %@", [colorNames objectAtIndex:index]);
statusLabel.text = [NSString stringWithFormat:@"Selected item is: %@", [colorNames objectAtIndex:index]];

switch ([colorNames objectAtIndex:])) {
    case 1:
        [redButton setImage:[UIImage imageNamed:@"Btn1_1.png"] forState:UIControlStateNormal];

        break;

    case 2:
        [redButton setImage:[UIImage imageNamed:@"Btn1_2.png"] forState:UIControlStateNormal];

        break;

    default:
        break;
}

这是我的if条件声明:

-(void) nearestIndexAfterRotationEnded:(int)index {
NSLog(@"Selected item is: %@", [colorNames objectAtIndex:index]);
statusLabel.text = [NSString stringWithFormat:@"Selected item is: %@", [colorNames objectAtIndex:index]];


if ([colorNames objectAtIndex:0]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_1.png"] forState:UIControlStateNormal];

}

if ([colorNames objectAtIndex:1]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_2.png"] forState:UIControlStateNormal];

}

if ([colorNames objectAtIndex:2]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_3.png"] forState:UIControlStateNormal];
}

if ([colorNames objectAtIndex:3]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_4.png"] forState:UIControlStateNormal];
}

if ([colorNames objectAtIndex:4]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_5.png"] forState:UIControlStateNormal];
}

if ([colorNames objectAtIndex:5]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_6.png"] forState:UIControlStateNormal];
}

if ([colorNames objectAtIndex:6]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_7.png"] forState:UIControlStateNormal];
}

if ([colorNames objectAtIndex:7]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_8.png"] forState:UIControlStateNormal];
}

if ([colorNames objectAtIndex:8]) {
    [redButton setImage:[UIImage imageNamed:@"Btn1_9.png"] forState:UIControlStateNormal];
}

}

谢谢你的帮助

Answer 1

- (void)nearestIndexAfterRotationEnded:(int)index {
    NSLog(@"Selected item is: %@", [colorNames objectAtIndex:index]);
    statusLabel.text = [NSString stringWithFormat:@"Selected item is: %@", [colorNames objectAtIndex:index]];

    for (int i=0; i<9; i++) {
        if ([colorNames objectAtIndex:i]) {
            [redButton setImage:[UIImage imageNamed:[NSString stringWithFormat:@"Btn1_%d.png", i+1]] forState:UIControlStateNormal];
        }
    }
}