UIPickerView 委托被无限次调用

Question

我有一个非常旧的应用程序，其中有 UIPickerView，其中委托方法被调用 n 次，因为哪个应用程序崩溃了。

以下是我所拥有的。

1. 我已经将 UIPickerView 连接到它的代理。

2. 我有标签，点击它，我会在 uipickerview 中显示性别。

   langLabel.userInteractionEnabled = YES;
   UITapGestureRecognizer *tapGestureRecognizergenderLabel = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(genderLabelTapped)];
   tapGestureRecognizergenderLabel.numberOfTapsRequired = 1;
   [langLabel addGestureRecognizer:tapGestureRecognizergenderLabel];
   [tapGestureRecognizergenderLabel release];
   
   -(void) genderLabelTapped {
       NSLog(@"genderLabelTapped");
       [normalPicker reloadAllComponents];
       normalPicker.hidden = NO;
       pickerImage.hidden = NO;
       continueButton.userInteractionEnabled = NO;
   }
   

3. 我有如下代表。

   #pragma mark -
   #pragma mark PickerView DataSource
   
   - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
   {
       NSLog(@"numberOfComponentsInPickerView");
       return 1;
   }
   
   -(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
   {
       CGRect screenRect = [[UIScreen mainScreen] bounds];
       CGFloat screenHeight = screenRect.size.height;
   
       if (screenHeight==568) {
           [pickerView setFrame: CGRectMake(10, 332, 300, 216)];
       } else {
           [pickerView setFrame: CGRectMake(10, 244, 300, 216)];
       }
       UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 204, 44)]; // your frame, so picker gets "colored"
   
       label.textColor = [UIColor blackColor];
       label.font = [UIFont fontWithName:[NSString stringWithFormat:@"%@", localize(@"myFontNameB")] size:14];
       label.textAlignment = NSTextAlignmentCenter;
   
       label.text = [NSString stringWithFormat:@"%@", [arrayGender objectAtIndex:row]];
       NSLog(@"changing font 1111...===%@", [arrayGender objectAtIndex:row]);
       return label;
   }
   
   - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
   {
       return [arrayGender count];
   }
   
   - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
   {
       return [arrayGender objectAtIndex:row];
   }
   

4. 我拥有的性别数组如下。

   arrayGender = [[NSMutableArray alloc] init];
   [arrayGender addObject:@"ENGLISH"];
   [arrayGender addObject:@"العربية"];
   

每当我运行这段代码时，我总是看到下面的输出...

    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===ENGLISH
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===العربية
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===ENGLISH
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===العربية
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===ENGLISH
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===العربية
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===ENGLISH
    Oct 24 12:36:25 HardTask-iPad AppName[543] <Warning>: changing font 1111...===العربية
    .
    .
    .
    Oct 24 12:36:26 HardTask-iPad AppName[543] <Warning>: changing font 1111...===ENGLISH
    Oct 24 12:36:26 HardTask-iPad AppName[543] <Warning>: changing font 1111...===العربية
    Oct 24 12:36:26 HardTask-iPad AppName[543] <Warning>: changing font 1111...===ENGLISH
    Oct 24 12:36:26 HardTask-iPad AppName[543] <Warning>: changing font 1111...===العربية

知道出了什么问题吗？

Answer 1

当您 setFrame 或 UIPickerView 时，它将调用 -(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view。

在这种情况下，要停止循环，请删除：

if (screenHeight==568) {
    [pickerView setFrame: CGRectMake(10, 332, 300, 216)];
} else {
    [pickerView setFrame: CGRectMake(10, 244, 300, 216)];
}

P/s：如果您想在其委托/回调方法中更改对象的任何内容，请谨慎操作。