iOS 常用公共方法（四）

原文連結：點選這裡

1、navigationBar變為純透明

//第一種方法
//導航欄純透明
[self.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
//去掉導航欄底部的黑線
self.navigationBar.shadowImage = [UIImage new];

//第二種方法
[[self.navigationBar subviews] objectAtIndex:].alpha = ;
           

tabBar同理

[self.tabBar setBackgroundImage:[UIImage new]];
self.tabBar.shadowImage = [UIImage new];
           

2、navigationBar根據滑動距離的漸變色實作

//第一種
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat offsetToShow = ;//滑動多少就完全顯示
    CGFloat alpha =  - (offsetToShow - scrollView.contentOffset.y) / offsetToShow;
    [[self.navigationController.navigationBar subviews] objectAtIndex:].alpha = alpha;
}
           

//第二種
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat offsetToShow = ;
    CGFloat alpha =  - (offsetToShow - scrollView.contentOffset.y) / offsetToShow;

    [self.navigationController.navigationBar setShadowImage:[UIImage new]];
    [self.navigationController.navigationBar setBackgroundImage:[self imageWithColor:[[UIColor orangeColor]colorWithAlphaComponent:alpha]] forBarMetrics:UIBarMetricsDefault];
}
           

3、生成一張純色的圖檔

- (UIImage *)imageWithColor:(UIColor *)color
{
    CGRect rect = CGRectMake(f, f, f, f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return theImage;
}
           

4、iOS 開發中一些相關的路徑

模拟器的位置:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs 

文檔安裝位置:
/Applications/Xcode.app/Contents/Developer/Documentation/DocSets

插件儲存路徑:
~/Library/ApplicationSupport/Developer/Shared/Xcode/Plug-ins

自定義代碼段的儲存路徑:
~/Library/Developer/Xcode/UserData/CodeSnippets/ 
如果找不到CodeSnippets檔案夾，可以自己建立一個CodeSnippets檔案夾。

描述檔案路徑
~/Library/MobileDevice/Provisioning Profiles