如何更改UIPickerView的文本大小和组件宽度？

Question

我有以下代码来创建UIPickerView：

pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0.0f, 416.0f - height, 320.0f, height)];
pickerView.delegate = self;
pickerView.showsSelectionIndicator = YES;
[pickerView setSoundsEnabled:YES];

我想更改组件宽度并更改每个组件中的文本大小。有可能这样做吗？

谢谢！

Answer 1

您可以通过适当的委托方法

更改宽度

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
    switch(component) {
        case 0: return 22;
        case 1: return 44;
        case 2: return 88;
        default: return 22;
    }

    //NOT REACHED
    return 22;
}

对于自定义文本大小，您可以使用委托返回所需大小文本的自定义视图：

- (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.text = @"Demo";
        retval.font = [UIFont systemFontOfSize:22];
        return retval;
}

当然，您需要修改这些内容才能为您的应用设置适当的值，但它应该可以让您到达目的地。