Question

我正在研究一个项目，我需要一些建议。我有这个按钮处理程序代码来处理我的所有按钮点击（如调查）。我想单击一个按钮，然后按钮将相应的对象添加到NSMutable数组。现在我的问题是使用可变数组或字典是否安全，因为可以添加或删除可变对象。以及如何检查对象是否正确添加到数组中。我有一个NSUInteger来查看对象是否正确添加但是我在数组1中的NSlog对象中接收，每当我点击另一个按钮添加另一个对象时，我收到相同的消息，但是它的NSlog再次打印1我不确定对象是否正确添加。

-(IBAction)checkBoxButtonHandler:(id)sender
{// array being allocated
    NSMutableArray *arrayOfselections = [NSMutableArray array];


    if (sender == checkButton1)

{

        if (!buttonChecked)
    {

        [arrayOfselections addObject:@"Freshman"];
        NSLog(@"Freshman Checked");

        [checkButton1 setImage:[UIImage imageNamed:@"checkBoxMarked.png"] forState:UIControlStateNormal];
        buttonChecked = YES;

    }
    else
    {
        [checkButton1 setImage:[UIImage imageNamed:@"checkBox.png"] forState:UIControlStateNormal];
        buttonChecked = NO;
    }


}

if (sender == checkB2)
{
    //    [arrayOfselections addObject:@"Sophmore"];
   // NSLog(@"check 2");

    if (!buttonChecked)
    {
        [arrayOfselections addObject:@"Sophmore"];
        NSLog(@"Sophmore Checked");
        [checkB2 setImage:[UIImage imageNamed:@"checkBoxMarked.png"] forState:UIControlStateNormal];
        buttonChecked = YES;

    }
    else
    {
        [checkB2 setImage:[UIImage imageNamed:@"checkBox.png"] forState:UIControlStateNormal];
        buttonChecked = NO;
    }

}
    [arrayOfselections accessibilityElementCount];

 if (sender == checkBox3)
    {

        //NSLog(@"check 3");

    if (!buttonChecked)
    {
        [arrayOfselections addObject:@"Junior"];
        NSLog(@"Junior Checked");
        [checkBox3 setImage:[UIImage imageNamed:@"checkBoxMarked.png"] forState:UIControlStateNormal];
        buttonChecked = YES;



    }
    else
    {
        [checkBox3 setImage:[UIImage imageNamed:@"checkBox.png"] forState:UIControlStateNormal];
        buttonChecked = NO;
    }


    }

  if (sender == checkBx4)
{

    NSLog(@"Checked 4");
    if (!buttonChecked)
    {
        [arrayOfselections addObject:@"Senior"];
        NSLog(@"Senior Checked");
        [checkBx4 setImage:[UIImage imageNamed:@"checkBoxMarked.png"] forState:UIControlStateNormal];
        buttonChecked = YES;

    }
    else
    {
        [checkBx4 setImage:[UIImage imageNamed:@"checkBox.png"] forState:UIControlStateNormal];
        buttonChecked = NO;
        }
NSUInteger arraySize = [arrayOfselections count];
NSLog(@"Number of stuff inside array: %ui",arraySize);
     }

Answer 1

每次按下按钮都会创建新数组，这发生在以下行中：

NSMutableArray *arrayOfselections = [NSMutableArray array];

您只需创建一次。最好的方法是将它移动到viewDidLoad方法，它应该完成这项工作。

Answer 2

您需要使数组成为视图控制器的属性：

MyViewController.m：

@interface MyViewController ()
@property (nonatomic) NSMutableArray *arrayOfSelections;
@end

在viewDidLoad中初始化：

- (void)viewDidLoad {
    [super viewDidLoad];
    self.arrayOfSelections = [NSMutableArray new];
    ...
}

-(IBAction)checkBoxButtonHandler:(id)sender
{   
    // Remove this line:
    //NSMutableArray *arrayOfselections = [NSMutableArray array];

    ...
    // and change any references to self.arrayOfSelections:
    [self.arrayOfselections addObject:@"Freshman"];
}

Answer 3

更漂亮的设计是使用标签和字典而不是if-else，所以

// assign tags:
checkButton1.tag = 1;
checkButton2.tag = 2;

// etc., then setup data beforehand
NSDictionary *mapTags = @{ @1:@"Freshman", @2:@"Sophomore" /* etc */ };
NSMutableArray *arrayOfselections = [NSMutableArray array];

// then look how small this gets:
-(IBAction)checkBoxButtonHandler:(id)sender {

    NSNumber *tagNumber = [NSNumber numberWithInt:sender.tag];
    [self.arrayOfselections addObject:self.mapTags[tagNumber]];
}

我的NSMutablearray是否在数组中添加对象和我的NSLog正确数量的对象？

3 个答案: