更改不同列的 UIPickerView 字体大小

Question

我正在构建一个 UIPickerView，它与我的以下代码配合使用效果很好。

//Title for Row
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{

    if (component==kNumComponent)
        return Number[row];
        else if(component==kSeaComponent)
            return Season[row];
        else
            return Course[row];

}

其中 Number、Season 和 Course 是存储字符串的 NSArray。这里我当然想把字号改小一点。我在这里学到了一些例子。

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row
forComponent:(NSInteger)component reusingView:(UIView *)view {
            UILabel *retval = (id)view;
            if (!retval) {
                retval= [[[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)] autorelease];
            }

            retval.font = [UIFont systemFontOfSize:22];
            retval.text = [pickerViewArray objectAtIndex:row];
       return retval;
    }

有什么快速的方法可以让我将上面的代码合并到我可用的代码中来更改字体大小吗？说吧，我想需要在某个地方传递 "Retval"？

更新：感谢 Scotts 的提示（见下文），我的方法有效，张贴在这里：

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row
          forComponent:(NSInteger)component reusingView:(UIView *)view {

    UILabel *retval = (UILabel*)view;
    if (!retval) {
        retval = [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)];
    }

    retval.font = [UIFont systemFontOfSize:22];

    if (component==kNumComponent)
        retval.text = Number[row];
    else if(component==kSeaComponent)
    {retval.font = [UIFont systemFontOfSize:14];
        retval.text = Season[row];}
    else
    { retval.font = [UIFont systemFontOfSize:14];
        retval.text = Course[row];}

    return retval;
}

Answer 1

要自定义选择器的视图，您必须使用 pickerView:viewForRow:。为此，请完全删除 pickerView:titleForRow:，并在 pickerView:viewForRow: 中使用您最初在 pickerView:titleForRow:.

中使用的条件设置 retval 的文本

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row
 forComponent:(NSInteger)component reusingView:(UIView *)view {

        UILabel *retval = (UILabel*)view;
        if (!retval) {
            retval = [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)];
        }

        retval.font = [UIFont systemFontOfSize:22];

        if (component==kNumComponent)
            retval.text = Number[row];
        else if(component==kSeaComponent)
            retval.text = Season[row];
        else
            retval.text = Course[row];

        return retval;
}

或者不创建标签子视图，您可以使用 UIPickerViewDelegate 的 pickerView:attributedTitleForRow:forComponent: 方法直接编辑标题的字体，例如：

- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    NSString *title;
    if (component==kNumComponent)
        title = Number[row];
    else if(component==kSeaComponent)
        title = Season[row];
    else
        title = Course[row];

    UIFont *font = [UIFont systemFontOfSize:22];
    NSDictionary *attributes = @{NSFontAttributeName:font};

    return [[NSAttributedString alloc] initWithString:title attributes:attributes];
}

更改不同列的 UIPickerView 字体大小

Change UIPickerView font size for different column

iphone

uipickerview

ios