-（void）viewDidLoad

{

　　　　//1.1背景圖片

　　UIImage *bgImage  [UIImage imageNamed:@"new"];

　　CGFloat w = bgImage.size.width;

　　CGFloat h = bgImage.size.width;

　　//1.創建圖形上下文

　　UIGraphicsBeginImageContextWithOptions(bgImage.size,NO,0.0);

　　　　//1.2.畫圖

　　[bgImage drawInRect:CGRectMake(0,0,w,h)];

　　//2.創建水印圖片

　　UIImage *iconImage = [UIImage imageNamed:@"logo"];

　　CGFloat iconW = iconImage.size.width * 0.2;

　　CGFloat iconH = iconImage.size.height *0.2;

　　CGFloat iconX = w - iconW - 5;

　　CGFloat iconY = h - iconH - 5;

　　//2.1畫圖

　　[iconImage drawInRect:CGRectMake(iconX,iconY,iconW,iocnH)];

　　//3.獲取當前的圖片

　　UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

　　//4.結束圖形

　　UIGraphicsEndImageContext();

　　self.imageView.image = newImage;

　　//5.打印

　　NSData *data = UIImagePNGRePResentation(newImage);

　　[data writeToFile:@"/User/apple/DeskTop/new.png" atomically:YES];

}