【iOS开发】---- UISegmentedControl在iOS 6与iOS 7下的异同

         

        在iOS 7下UISegmentedControl外观不仅与iOS 6不一样，而且iOS 7下UISegmentedControl的触摸状态也比iOS 6多了一种：高亮状态（UIControlStateHighlighted）。所以在iOS 6的时候，设置自定义外观需要添加高亮状态时的外观。

        前面有篇文章介绍了在iOS 5以后可以用UIAppearance来全局设置外观。今天在项目碰到个问题：有两处使用UISegmentedControl的地方外观不一样，好在UIAppearance有appearanceWhenContainedIn：这个方法，可以很方便的实现需求。不过如果按照前面的文章里那样写，估计代码量不少。在这里我把公用的代码抽出，这样不但代码量减少，看起来也会相当清晰：

        公用的代码如下：

-(void)segmentControlAppearanceContainedIn:(Class <UIAppearanceContainer>)ContainerClass
                              withMaterial:(NSDictionary *)material
{
    id appearance = [UISegmentedControl appearanceWhenContainedIn:ContainerClass, nil];
    
    //文本
    [appearance setTitleTextAttributes:[material objectForKey:@"TextAttributes_Highlighted"]
                              forState:UIControlStateHighlighted];
    [appearance setTitleTextAttributes:[material objectForKey:@"TextAttributes_Selected"]
                              forState:UIControlStateSelected];
    [appearance setTitleTextAttributes:[material objectForKey:@"TextAttributes_Normal"]
                              forState:UIControlStateNormal];
    
    //文字位置
    [appearance setContentPositionAdjustment:UIOffsetMake(0, 3)
                              forSegmentType:UISegmentedControlSegmentAny
                                  barMetrics:UIBarMetricsDefault];
    
    //背景
    [appearance setBackgroundImage:[material objectForKey:@"Bg_Normal"]
                          forState:UIControlStateNormal
                        barMetrics:UIBarMetricsDefault];
    [appearance setBackgroundImage:[material objectForKey:@"Bg_Selected"]
                          forState:UIControlStateSelected
                        barMetrics:UIBarMetricsDefault];
    [appearance setBackgroundImage:[material objectForKey:@"Bg_Highlighted"]
                          forState:UIControlStateHighlighted
                        barMetrics:UIBarMetricsDefault];
    
    //分割线
    //Unselected | Unselected
    [appearance setDividerImage:[material objectForKey:@"Divider_Unselected_Unselected"]
            forLeftSegmentState:UIControlStateNormal
              rightSegmentState:UIControlStateNormal
                     barMetrics:UIBarMetricsDefault];
    //Selected | Unselected
    [appearance setDividerImage:[material objectForKey:@"Divider_Selected_Unselected"]
            forLeftSegmentState:UIControlStateSelected
              rightSegmentState:UIControlStateNormal
                     barMetrics:UIBarMetricsDefault];
    //Unselected | Selected
    [appearance setDividerImage:[material objectForKey:@"Divider_Unselected_Selected"]
            forLeftSegmentState:UIControlStateNormal
              rightSegmentState:UIControlStateSelected
                     barMetrics:UIBarMetricsDefault];
}

        material是需要添加的素材：文本属性，背景，分割线等。ContainerClass表示你需要只在哪个类中实现这个外观，示例如下：

//文本
        NSDictionary *dic_TextAttributes_Highlighted = @{
                                                         UITextAttributeTextColor: [UIColor grayColor],
                                                         UITextAttributeTextShadowOffset:[NSValue valueWithCGSize:CGSizeMake(0, 0)],
                                                         UITextAttributeFont:[self SDFontWithFamilyName:_SubTitleFontName_ size:13.0f]
                                                         };
        NSDictionary *dic_TextAttributes_Selected    = @{
                                                         UITextAttributeTextColor: [UIColor whiteColor],
                                                         UITextAttributeTextShadowOffset:[NSValue valueWithCGSize:CGSizeMake(0, 0)],
                                                         UITextAttributeFont:[self SDFontWithFamilyName:_SubTitleFontName_ size:13.0f]
                                                         };
        NSDictionary *dic_TextAttributes_Normal      = @{
                                                         UITextAttributeTextColor: [UIColor grayColor],
                                                         UITextAttributeTextShadowOffset:[NSValue valueWithCGSize:CGSizeMake(0, 0)],
                                                         UITextAttributeFont:[self SDFontWithFamilyName:_SubTitleFontName_ size:13.0f]
                                                         };
        //背景
        UIImage *bg_Normal      = [[[UIImage imageNamed:@"whiteDot_1pix.png"]imageWithTintColor:[UIColor whiteColor]]  resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0,0)];
        UIImage *bg_Selected    = [[[UIImage imageNamed:@"whiteDot_1pix.png"] imageWithTintColor:[UIColor grayColor]] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];
        UIImage *bg_Highlighted = [[[UIImage imageNamed:@"whiteDot_1pix.png"] imageWithGradientTintColor:HighLightColor_SegmentControl_In_Product] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];
        
        //分割线
        UIImage *divider_U_U = [[UIImage imageNamed:@"bgSegmentDivider.png"] imageWithTintColor:[UIColor grayColor]];
        UIImage *divider_S_U = [[UIImage imageNamed:@"bgSegmentDivider.png"] imageWithTintColor:[UIColor grayColor]];
        UIImage *divider_U_S = [[UIImage imageNamed:@"bgSegmentDivider.png"] imageWithTintColor:[UIColor grayColor]];
        
        NSDictionary *material = @{@"TextAttributes_Highlighted":dic_TextAttributes_Highlighted,
                                   @"TextAttributes_Selected":dic_TextAttributes_Selected,
                                   @"TextAttributes_Normal":dic_TextAttributes_Normal,
                                   @"Bg_Normal":bg_Normal,
                                   @"Bg_Selected":bg_Selected,
                                   @"Bg_Highlighted":bg_Highlighted,
                                   @"Divider_Unselected_Unselected":divider_U_U,
                                   @"Divider_Selected_Unselected":divider_S_U,
                                   @"Divider_Unselected_Selected":divider_U_S};
        [self segmentControlAppearanceContainedIn:nil withMaterial:material];

         虽然看起来还是很多，但是都是必须的，以后类似其它的视图如果也有多种全局外观需要设置，方便起见，也可以这样写。

        上面的代码是iOS 6和iOS同时UISegmentedControl外观设置。如果只在iOS7进行外观设置，是非常简单的，代码如下：

        id appearance = [UISegmentedControl appearance];
        [appearance setTintColor:[UIColor grayColor]];
        appearance = [UISegmentedControl appearanceWhenContainedIn:[UINavigationBar class], nil];
        [appearance setTintColor:[UIColor whiteColor]];