Question

我正在处理一个脚本，该脚本循环遍历一系列LED UIImageView，它们按数字顺序设置并由标签选择。根据步骤（又名号码），led图像上的显示为开或关。此方法的主要目标是采用当前步骤并在＆＃34;上显示＆＃34; LED。将图像减去1并显示＆＃34; LED熄灭＆＃34;上一步的图像。因此，一次只能点亮一个LED。

不幸的是，我只能打开＆＃34; LED？图像显示正确。序列中的所有LED都亮起，但它们从不关闭。我的第一个猜测是我没有以正确的方式减去NSInterger。但是，当我检查日志时，一切都应该是它。如果当前步骤为2，则先前为1.不知道为什么这不起作用。谢谢！

sequencerLocation和previousLocation都设置为属性。

- (void)clockLoop:(UInt8)seqClockPulse
{
//cast to an int to use in loop
NSInteger stepCount = sequencerSteps;

//increment sequencer on pulse in
sequencerLocation++;

if(sequencerLocation > stepCount)
{
    sequencerLocation = 1;
}

//setup previous step location
previousLocation = (sequencerLocation - 1);

if (previousLocation == 0)
{
    previousLocation = stepCount;
}

//change led color in led array
for (UIImageView *led in sequencerLEDArray)
{
    if(led.tag == sequencerLocation)
    {
        UIImageView *previousLed = (UIImageView *)[led viewWithTag:previousLocation];
        [previousLed setImage:[UIImage imageNamed:@"images/seq_LED_off.png"]];
        NSLog(@"Previous: %d", previousLocation);

        UIImageView *currentLed = (UIImageView *)[led viewWithTag:sequencerLocation];
        [currentLed setImage:[UIImage imageNamed:@"images/seq_LED_on.png"]];
        NSLog(@"Current: %d", sequencerLocation);
    }
}

}

Answer 1

//change led color in led array
for (UIImageView *led in sequencerLEDArray)
{
if(led.tag == sequencerLocation)
{
    //  I THINK the problem is here
  //  UIImageView *previousLed = (UIImageView *)[led viewWithTag:previousLocation];
    //  TRY THIS instead
    UIImageView *previousLed = [led.superview viewWithTag:previousLocation];
    [previousLed setImage:[UIImage imageNamed:@"images/seq_LED_off.png"]];
    NSLog(@"Previous: %d", previousLocation);

    // HERE you don't need to search for the tag you already tested for it in your if statement
    UIImageView *currentLed = (UIImageView *)[led viewWithTag:sequencerLocation];
    [currentLed setImage:[UIImage imageNamed:@"images/seq_LED_on.png"]];
    NSLog(@"Current: %d", sequencerLocation);
}
}

viewWithTag：
Discussion

此方法搜索指定视图的当前视图及其所有子视图。

所以，当你从它自己的标签中搜索led时，它会自行返回，但是当你搜索它的兄弟时它没有找到它，这就是为什么我建议将led.superview作为地方为了搜索您的标签，父母应该能够找到其他孩子。

根据标记设置UIImage

1 个答案: