给图片增加水印 UIImage+Category

// // UIImage+Category.h // Created by Dennis Deng on 12/05/04. // #import <UIKit/UIKit.h> @interface UIImage (wiCategory) // 裁剪图片 - (UIImage *) imageCroppedToRect:(CGRect)rect; // 裁减正方形区域 - (UIImage *) squareImage; // 画水印 // 图片水印 - (UIImage *) imageWithWaterMask:(UIImage*)mask inRect:(CGRect)rect; // 文字水印 - (UIImage *) imageWithStringWaterMark:(NSString *)markString inRect:(CGRect)rect color:(UIColor *)color font:(UIFont *)font; - (UIImage *) imageWithStringWaterMark:(NSString *)markString atPoint:(CGPoint)point color:(UIColor *)color font:(UIFont *)font; // 蒙板 - (void) drawInRect:(CGRect)rect withImageMask:(UIImage*)mask; - (void) drawMaskedColorInRect:(CGRect)rect withColor:(UIColor*)color; // 保存图像文件 - (BOOL) writeImageToFileAtPath:(NSString*)aPath; @end