#import <UIKit/UIKit.h>@interface watermarkView : UIImageView/** 設置水印 @param frame 水印大小 @param markText 水印顯示的文字 */- (instancetype)initWithFrame:(CGRect)frame WithText:(NSString *)markText;@end

#import "watermarkView.h"#define HORIZONTAL_SPACE 30//水平間距#define VERTICAL_SPACE 50//豎直間距#define CG_TRANSFORM_ROTATION (M_PI_2 / 3)//旋轉角度(正旋45度 || 反旋45度)@implementation watermarkView- (instancetype)initWithFrame:(CGRect)frame WithText:(NSString *)markText{ if(self = [super initWithFrame:frame]){    UIFont *font = [UIFont systemFontOfSize:14];    UIColor *color = YTHColorAlpha(152, 152, 152, 0.1);    //原始image的寬高  CGFloat viewWidth = frame.size.width;  CGFloat viewHeight = frame.size.height;    //為了防止圖片失真，繪制區域寬高和原始圖片寬高一樣  UIGraphicsBeginImageContext(CGSizeMake(viewWidth, viewHeight));    //sqrtLength：原始image的對角線length。在水印旋轉矩陣中只要矩陣的寬高是原始image的對角線長度，無論旋轉多少度都不會有空白。  CGFloat sqrtLength = sqrt(viewWidth*viewWidth + viewHeight*viewHeight);  //文字的屬性  NSDictionary *attr = @{        //設置字體大小        NSFontAttributeName: font,        //設置文字顏色        NSForegroundColorAttributeName :color,        };  NSString* mark = markText;  NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithString:mark attributes:attr];  //繪制文字的寬高  CGFloat strWidth = attrStr.size.width;  CGFloat strHeight = attrStr.size.height;    //開始旋轉上下文矩陣，繪制水印文字  CGContextRef context = UIGraphicsGetCurrentContext();    //將繪制原點（0，0）調整到原image的中心  CGContextConcatCTM(context, CGAffineTransformMakeTranslation(viewWidth/2, viewHeight/2));  //以繪制原點為中心旋轉  CGContextConcatCTM(context, CGAffineTransformMakeRotation(CG_TRANSFORM_ROTATION));  //將繪制原點恢復初始值，保證當前context中心和源image的中心處在一個點(當前context已經旋轉，所以繪制出的任何layer都是傾斜的)  CGContextConcatCTM(context, CGAffineTransformMakeTranslation(-viewWidth/2, -viewHeight/2));    //計算需要繪制的列數和行數  int horCount = sqrtLength / (strWidth + HORIZONTAL_SPACE) + 1;  int verCount = sqrtLength / (strHeight + VERTICAL_SPACE) + 1;    //此處計算出需要繪制水印文字的起始點，由于水印區域要大于圖片區域所以起點在原有基礎上移  CGFloat orignX = -(sqrtLength-viewWidth)/2;  CGFloat orignY = -(sqrtLength-viewHeight)/2;    //在每列繪制時X坐標疊加  CGFloat tempOrignX = orignX;  //在每行繪制時Y坐標疊加  CGFloat tempOrignY = orignY;  for (int i = 0; i < horCount * verCount; i++) {   [mark drawInRect:CGRectMake(tempOrignX, tempOrignY, strWidth, strHeight) withAttributes:attr];   if (i % horCount == 0 && i != 0) {    tempOrignX = orignX;    tempOrignY += (strHeight + VERTICAL_SPACE);   }else{    tempOrignX += (strWidth + HORIZONTAL_SPACE);   }  }  //根據上下文制作成圖片    UIImage *finalImg = UIGraphicsGetImageFromCurrentImageContext();  UIGraphicsEndImageContext();  CGContextRestoreGState(context);    self.image = finalImg; }  return self;}-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{  //1.判斷自己能否接收事件 if(self.userInteractionEnabled == NO || self.hidden == YES || self.alpha <= 0.01) {  return nil; } //2.判斷當前點在不在當前View. if (![self pointInside:point withEvent:event]) {  return nil; } //3.從后往前遍歷自己的子控件.讓子控件重復前兩步操作,(把事件傳遞給,讓子控件調用hitTest) int count = (int)self.subviews.count; for (int i = count - 1; i >= 0; i--) {  //取出每一個子控件  UIView *chileV = self.subviews[I];  //把當前的點轉換成子控件坐標系上的點.  CGPoint childP = [self convertPoint:point toView:chileV];  UIView *fitView = [chileV hitTest:childP withEvent:event];  //判斷有沒有找到最適合的View  if(fitView){   return fitView;  } }  //4.沒有找到比它自己更適合的View.那么它自己就是最適合的View return self;}//作用:判斷當前點在不在它調用View,(誰調用pointInside,這個View就是誰)//什么時候調用:它是在hitTest方法當中調用的.//注意:point點必須得要跟它方法調用者在同一個坐標系里面-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event{ NSLog(@"%s",__func__); return NO;}

 //加水印 watermarkView *watermark = [[watermarkView alloc] initWithFrame:CGRectMake(0, 0, KScreenW, KScreenH) WithText:@"測試"]; [self.view addSubview:watermark];