Question

我正在开发一个计算器应用程序，我试图通过更改背景颜色突出显示触摸的按钮。我的问题是，当我第一次触摸按钮时，它会显示数字，但背景颜色不会改变。但后来它工作正常，只是第一次触摸根本不起作用。我感谢任何帮助！

#import "ViewController.h"
#import <QuartzCore/QuartzCore.h>
#import <AudioToolbox/AudioToolbox.h>

@interface ViewController ()

@end

@implementation ViewController
@synthesize resultLabel;

BOOL isDecimal;
NSArray *array;
NSNumber *number;
NSNumberFormatter *formatter;

- (void)viewDidLoad
{
    [super viewDidLoad];

    array = [[NSArray alloc]initWithObjects:ACbuttonOutlet, deleteButtonOutlet, plusMinusOutlet, divideOutlet, number7Outlet, number8Outlet, number9Outlet, multiplicationOutlet, number4Outlet, number5Outlet, number6Outlet, plusOutlet, number1Outlet, number2Outlet, number3Outlet, minusOutlet, number0Outlet, decimalOutlet, resultOutlet, nil];

    for(UIButton *button in array)

    {
        [button.layer setBorderWidth:0.25];
        [button.layer setBorderColor:[UIColor blackColor].CGColor];
    }

    resultLabel.adjustsFontSizeToFitWidth = YES;

    /*formatter = [[NSNumberFormatter alloc]init];
    [formatter setNumberStyle:NSNumberFormatterDecimalStyle];
    [formatter setGroupingSize:3];
    [formatter setGroupingSeparator:@" "];
    number = [NSNumber numberWithInt:[resultLabel.text intValue]];
    resultLabel.text = [formatter stringFromNumber:number];*/

    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(void)highlightButton:(UIButton *)button
{
    AudioServicesPlaySystemSound(0x450);
    [button setBackgroundColor:[UIColor colorWithRed:239/255.0 green:232/255.0 blue:232/255.0 alpha:1]];
    NSLog(@"1");
}

- (void)resetButtonBackGroundColor: (UIButton *)sender{
    [sender setBackgroundColor:[UIColor whiteColor]];
    NSLog(@"2");
}

- (IBAction)ACbutton:(id)sender  {

    [sender addTarget:self action:@selector(highlightButton:) forControlEvents:UIControlEventTouchDown];
    [sender addTarget:self action:@selector(resetButtonBackGroundColor:) forControlEvents:UIControlEventTouchUpInside];

    isDecimal = NO;
    Method = 0;
    SelectNumber = 0;
    RunningTotal = 0;
    resultLabel.text = [NSString stringWithFormat:@"0"];
}

Answer 1

尝试将viewDidLoad方法中的这一行添加到循环中

for(UIButton *button in array)

    {


        [button.layer setBorderWidth:0.25];
        [button.layer setBorderColor:[UIColor blackColor].CGColor];
        [button addTarget:self action:@selector(highlightButton:)   forControlEvents:UIControlEventTouchDown];

    }

Answer 2

我建议你不要使用按钮的背景颜色。而是切换/更改按钮的背景图像。

IBAction addTarget：action：forControlEvents：第一次触摸时不工作，否则很好

2 个答案: