iOS开发代码片段整理.Part1

1.将NavigationBar设置为透明

在viewWillAppear中

[self.navigationController.navigationBar setBackgroundImage:[UIImage imageWithColor:[UIColor colorWithRed:0 green:0 blue:0 alpha:0]] forBarMetrics:0];
[self.navigationController.navigationBar setShadowImage:[UIImage imageWithColor:[UIColor colorWithRed:0 green:0 blue:0 alpha:0]]];

记得在viewWillDisappear中设置回原来的颜色

[self.navigationController.navigationBar setBackgroundImage:[UIImage imageWithColor:BlackCustom] forBarMetrics:0];
[self.navigationController.navigationBar setShadowImage:[UIImage imageWithColor:BlackCustom]];

2.创建纯色图片

@interface UIImage (ImageExtend）
+ (UIImage *)imageWithColor:(UIColor *)color;
@end

@implementation  UIImage (ImageExtend)

+ (UIImage *)imageWithColor:(UIColor *)color {
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return image;
}

3.水印图片

/**
 加半透明水印
 @param useImage 需要加水印的图片
 @param addImage1 水印
 @returns 加好水印的图片
 */
+ (UIImage *)addImage:(UIImage *)useImage addMaskImage:(UIImage *)maskImage
{
    CGFloat w = useImage.size.width;
    CGFloat h = useImage.size.height;
    
    //TV提供的useImage的尺寸有所不同，用scale作统一化
    CGFloat scale = w /1920.0;
    //NSLog(@"scale:%f",scale);
    
    //这个数值不是pt，且为px ; 应按照画布的坐标体系（左下角为原点）
    CGFloat logoWidth = maskImage.size.width*scale;
    CGFloat logoHeight = maskImage.size.height*scale;
    //NSLog(@"useImageWidth:%f,useImageHeight:%f",w,h);
    //NSLog(@"logoWidth:%f,logoHeight:%f",logoWidth,logoHeight);
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    //create a graphic context with CGBitmapContextCreate
    CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 44 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
    CGContextDrawImage(context, CGRectMake(0, 0, w, h), useImage.CGImage);
    CGContextDrawImage(context, CGRectMake(w-logoWidth, 0, logoWidth, logoHeight), [maskImage CGImage]);
    CGImageRef imageMasked = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    return [UIImage imageWithCGImage:imageMasked];
}

注意：用image.size.width得到的尺寸，在数值上是原图useImage的尺寸，单位为px，所以原图的分辨率直接影响了最后水印的尺寸，所以要做了一下同一化。

4. RGBA与Hex Color

//#根据十六进制换算成颜色
#define UIColorBaseRGB(rgbValue) \
[UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]
//#根据十进制换算成颜色并可以设置透明度
#define RGBACOLOR(r,g,b,a) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f \
alpha:(a)]

5.设备信息

#define INTERFACE_IS_PAD     ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad)
#define INTERFACE_IS_PHONE   ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
#define isPhone5 ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size) : NO)
#define isPadMini ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(768, 1024), [[UIScreen mainScreen] currentMode].size) : NO)

#define ScreenHeight [[UIScreen mainScreen] bounds].size.height
#define ScreenWidth  [[UIScreen mainScreen] bounds].size.width

#define DEV_UUID [[UIDevice currentDevice].identifierForVendor UUIDString]

#define BUNDLE_VERSION NSDictionary [[[NSBundle mainBundle] infoDictionary]objectForKey:@"CFBundleShortVersionString"]