ios -bitmap上下文產生圖片 產生浮水印

標籤：gpo   nss   contex   context   rect   pat   make   point   image   

- (void)test{    // 0. 載入背景圖片    UIImage *image = [UIImage imageNamed:@"psb"];    // 1.建立bitmap上下文    // 執行完這一行在記憶體中就相遇建立了一個UIImage    UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);    // 2.繪圖圖片    // 2.1繪製背景圖片    [image drawAtPoint:CGPointMake(0, 0)];    // 2.2繪製浮水印     UIImage *logImage = [UIImage imageNamed:@"logo1"];     CGFloat margin = 10;     CGFloat logY = margin;     CGFloat logX = image.size.width - margin - logImage.size.width;     [logImage drawAtPoint:CGPointMake(logX, logY)];    // 2.3繪製文字浮水印    NSString *str = @"黑馬程式員";    [str drawAtPoint:CGPointMake(150, 50) withAttributes:nil];    // 3.獲得bitmap上下文中繪製號的圖片    UIImage *newImage =  UIGraphicsGetImageFromCurrentImageContext();    // 4.將圖片寫到檔案中    NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"aaa.png"];    NSLog(@"%@", path);    NSData *data = UIImagePNGRepresentation(newImage);    [data writeToFile:path atomically:YES];}

 

ios -bitmap上下文產生圖片 產生浮水印