iphone - UIPickerView EXC 访问错误？

Question

我不断收到错误访问错误，我认为这与我的 UIPickerView 有关，因为这是应用程序崩溃的时候。一切正常，直到我从 UIPickerView 中做出第九个选择。每次应用程序在第 9 个选择时崩溃。有什么想法吗？

- (void)viewDidLoad {
        [super viewDidLoad];



     list = [[NSMutableArray alloc] init];
     [list addObject:@"Anvil"];
     [list addObject:@"Apple"];
     [list addObject:@"Arrow"];
     [list addObject:@"Baby"];
     [list addObject:@"Basketball"];
     [list addObject:@"Beehive"];
     [list addObject:@"Blimp"];
     [list addObject:@"Bomb"];
     [list addObject:@"Bungee Jumper"];
     [list addObject:@"Cactus"];
     [list addObject:@"Cake"];
     [list addObject:@"Car"];
     [list addObject:@"Caterpillar"];
     [list addObject:@"Couch"];
     [list addObject:@"Dennis"];

        anvil = [UIImage imageNamed:@"anvil.png"];
     apple = [UIImage imageNamed:@"apple.png"];
     arrow = [UIImage imageNamed:@"arrow.png"];
     baby = [UIImage imageNamed:@"baby.png"];
     basketball = [UIImage imageNamed:@"basketball.png"];
     beehive = [UIImage imageNamed:@"beehive.png"];
     blimp = [UIImage imageNamed:@"blimp.png"];
     bomb = [UIImage imageNamed:@"bomb.png"];
     bungeejumper = [UIImage imageNamed:@"bungeejumper.png"];
     cactus = [UIImage imageNamed:@"cactus.png"];
     cake = [UIImage imageNamed:@"cake.png"];
     car = [UIImage imageNamed:@"car.png"];
     caterpillar = [UIImage imageNamed:@"caterpillar.png"];
     couch = [UIImage imageNamed:@"couch.png"];
     dennis = [UIImage imageNamed:@"dennis.png"];
    }

    -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)thePickerView{
     return 1;
    }

    -(NSInteger)pickerView:(UIPickerView *)thePickerView numberOfRowsInComponent:(NSInteger)component{

     return [list count];
    }

    -(NSString *)pickerView:(UIPickerView *)thePickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{

     return [list objectAtIndex:row];
    }

    - (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {

     if([[list objectAtIndex:row] isEqual:@"Anvil"]) {
      [object setImage:anvil];
     }
     else if([[list objectAtIndex:row] isEqual:@"Apple"]) {
      [object setImage:apple];
     }
     else if([[list objectAtIndex:row] isEqual:@"Arrow"]) {
      [object setImage:arrow];
     }
     else if([[list objectAtIndex:row] isEqual:@"Baby"]) {
      [object setImage:baby];
     }
     else if([[list objectAtIndex:row] isEqual:@"Basketball"]) {
      [object setImage:basketball];
     }
     else if([[list objectAtIndex:row] isEqual:@"Beehive"]) {
      [object setImage:beehive];
     }
     else if([[list objectAtIndex:row] isEqual:@"Blimp"]) {
      [object setImage:blimp];
     }
     else if([[list objectAtIndex:row] isEqual:@"Bomb"]) {
      [object setImage:bomb];
     }
     else if([[list objectAtIndex:row] isEqual:@"Bungee Jumper"]) {
      [object setImage:bungeejumper];
     }
     else if([[list objectAtIndex:row] isEqual:@"Cactus"]) {
      [object setImage:cactus];
     }
     else if([[list objectAtIndex:row] isEqual:@"Cake"]) {
      [object setImage:cake];
     }
     else if([[list objectAtIndex:row] isEqual:@"Car"]) {
      [object setImage:car];
     }
     else if([[list objectAtIndex:row] isEqual:@"Caterpillar"]) {
      [object setImage:caterpillar];
     }
     else if([[list objectAtIndex:row] isEqual:@"Couch"]) {
      [object setImage:couch];
     }
     else if([[list objectAtIndex:row] isEqual:@"Dennis"]) {
      [object setImage:dennis];
     }
    }

- (void)dealloc {
 [list release];
    [super dealloc];
 [animation release];
}

Answer 1

您没有保留 UIImage，因此它们会自动释放。每次 imageNamed 调用后，您都需要保留，即

baby = [[UIImage imageNamed:@"baby.png"] retain];

或者，如果您已将它们声明为属性(即 @property (nonatomic, keep) UIImage *baby;)，您可以执行以下操作:

self.baby = [UIImage imageNamed:@"baby.png"];

这是更正确的方法。

<小时/>

但是，处理所有这些代码的更好方法可能是使用图像数组，而不是每次都检查名称。即

imageArray = [NSArray alloc] initWithObjects:
              [UIImage imageNamed:@"Anvil.png"],
              [UIImage imageNamed:@"Apple.png"],
              [UIImage imageNamed:@"Arrow.png"],
              nil];

然后，当选择一个项目时，

- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    [object setImage:[imagearray objectAtIndex:row]];
 }

这更干净一点;)

编辑:Douglas当我写答案的后半部分时，我也有同样的清理代码的想法:)