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了 n 次，因此应用程序崩溃了。

下面是我的。

我已经将 UIPickerView 连接到它的委托。

我有标签，点击它，我在 uipickerview 中显示了性别。

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;
}

我有以下代表。

#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];
}

我的性别数组如下。

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 of UIPickerView 时，它会调用 -(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view。

在这种情况下，要停止循环，删除：

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

P/s：如果你想在它的delegate/callback方法中改变一个对象的任何东西，小心做。

UIPickerView 委托被无限次调用

UIPickerView delegate is called infinite number of times

delegates

objective-c

uipickerview

ios