1、绘制画板

1.1 绘制简单画板

• PaintBoardView.h

      @interface PaintBoardView : UIView
  
      @end

• PaintBoardView.m

      @interface PaintBoardView ()
  
      /// 路径
      @property (nonatomic, strong) UIBezierPath *path;
  
      /// 保存所有路径的数组
      @property (nonatomic, strong) NSMutableArray *pathsArrayM;
  
      @end
  
      @implementation PaintBoardView
  
      /// 初始化
      - (instancetype)initWithFrame:(CGRect)frame {
  
          if (self = [super initWithFrame:frame]) {
              self.backgroundColor = [UIColor whiteColor];
          }
          return self;
      }
  
      /// 触摸开始
      - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
  
          // 获取触摸起始点位置
          CGPoint startPoint = [touches.anyObject locationInView:self];
  
          // 添加路径描绘起始点
          [self.path moveToPoint:startPoint];
  
          // 添加一条触摸路径描绘
          [self.pathsArrayM addObject:self.path];
      }
  
      /// 触摸移动
      - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
  
          // 获取触摸点位置
          CGPoint touchPoint = [touches.anyObject locationInView:self];
  
          // 添加路径描绘
          [self.path addLineToPoint:touchPoint];
  
          // 刷新视图
          [self setNeedsDisplay];
      }
  
      /// 触摸结束
      - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
  
          // 获取绘制结果
          UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0);
          CGContextRef ctx = UIGraphicsGetCurrentContext();
          [self.layer renderInContext:ctx];
          UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
          UIGraphicsEndImageContext();
  
          NSData *data = UIImagePNGRepresentation(image);
          [data writeToFile:@"/Users/JHQ0228/Desktop/Images/pic.png" atomically:YES];
      }
  
      /// 触摸取消
      - (void)touchesCancelled:(NSSet *)touches withEvent:(nullable UIEvent *)event {
          [self touchesEnded:touches withEvent:event];
      }
  
      /// 绘制图形
      - (void)drawRect:(CGRect)rect {
  
          for (UIBezierPath *path in self.pathsArrayM) {
  
              // 绘制路径
              [path stroke];
          }
      }
  
      /// 懒加载
  
      - (UIBezierPath *)path {
  
          if (_path == nil) {
              _path = [UIBezierPath bezierPath];
          }
          return _path;
      }
  
      - (NSMutableArray *)pathsArrayM {
  
          if (_pathsArrayM == nil) {
              _pathsArrayM = [NSMutableArray array];
          }
          return _pathsArrayM;
      }
  
      @end

• ViewController.m

      // 创建画板
      CGRect frame = CGRectMake(20, 50, self.view.bounds.size.width - 40, 200);
      PaintBoardView *paintBoard = [[PaintBoardView alloc] initWithFrame:frame];
  
      [self.view addSubview:paintBoard];

• 效果

  

1.2 绘制画板封装

• 具体实现代码见 GitHub 源码 QExtension

• QPaintBoardPath.h

      @interface QPaintBoardPath : UIBezierPath
  
      /// 线的颜色
      @property (nonatomic, strong) UIColor *pathColor;
  
      /// 线的宽度
      @property (nonatomic, assign) CGFloat pathWidth;
  
      @end

• QPaintBoardPath.m

      @implementation QPaintBoardPath
  
      @end

• QPaintBoardView.h

      @interface QPaintBoardView : UIView
  
      /// 画线的宽度，default is 1，max is 30
      @property (nonatomic, assign) CGFloat paintLineWidth;
  
      /// 画笔的颜色，default is blackColor
      @property (nonatomic, strong) UIColor *paintLineColor;
  
      /// 画板的颜色，default is whiteColor
      @property (nonatomic, strong) UIColor *paintBoardColor;
  
      /**
       *  创建画板视图控件，获取绘画结果
       *
       *  @param frame        画板视图控件 frame
       *  @param lineWidth    画笔的线宽，default is 1，max is 30
       *  @param lineColor    画笔的颜色，default is blackColor
       *  @param boardColor   画板的颜色，default is whiteColor
       *  @param result       绘画结果
       *
       *  @return 手势锁视图控件
       */
      + (instancetype)q_paintBoardViewWithFrame:(CGRect)frame
                                      lineWidth:(CGFloat)lineWidth
                                      lineColor:(nullable UIColor *)lineColor
                                     boardColor:(nullable UIColor *)boardColor
                                    paintResult:(void (^)(UIImage * _Nullable image))result;
  
      /**
       *  创建简单画板视图控件
       *
       *  @param frame    画板视图控件 frame
       *
       *  @return 手势锁视图控件
       */
      + (instancetype)q_paintBoardViewWithFrame:(CGRect)frame;
  
      /**
       *  获取绘画结果
       *
       *  @return 绘画结果图片
       */
      - (UIImage * _Nullable)q_getPaintImage;
  
      /**
       *  清除绘画结果
       */
      - (void)q_clear;
  
      /**
       *  撤销绘画结果
       */
      - (void)q_back;
  
      @end

• QPaintBoardView.m

      #import "QPaintBoardPath.h"
  
      @interface QPaintBoardView ()
  
      /// 路径
      @property (nonatomic, strong, nullable) QPaintBoardPath *path;
  
      /// 保存所有路径的数组
      @property (nonatomic, strong) NSMutableArray *pathsArrayM;
  
      /// 绘画结果
      @property (nonatomic, copy) void (^resultBlock)(UIImage * _Nullable);
  
      /// 按钮工具条
      @property (nonatomic, strong) UIView *toolView;
  
      /// 画笔设置视图
      @property (nonatomic, strong) UIView *brushSetingView;
  
      /// 颜色选择视图
      @property (nonatomic, strong) UIScrollView *colorSelectedView;
  
      /// 画板设置视图
      @property (nonatomic, strong) UIScrollView *boardSetingView;
  
      /// 记录线的颜色
      @property (nonatomic, strong) UIColor *lastPaintLineColor;
  
      /// 记录线的宽度
      @property (nonatomic, assign) CGFloat lastPaintLineWidth;
  
      @end
  
      @implementation QPaintBoardView
  
      #pragma mark - 创建画板
  
      /// 创建画板视图控件，获取绘画结果
      + (instancetype)q_paintBoardViewWithFrame:(CGRect)frame
                                      lineWidth:(CGFloat)lineWidth
                                      lineColor:(nullable UIColor *)lineColor
                                     boardColor:(nullable UIColor *)boardColor
                                    paintResult:(void (^)(UIImage * _Nullable image))result {
  
          QPaintBoardView *paintBoardView = [[self alloc] init];
  
      //    CGRect tmpFrame = frame;
      //    tmpFrame.size.height = frame.size.height + 44;
  
          paintBoardView.frame = frame;
          paintBoardView.paintLineWidth = (lineWidth > 30 ? 30 : lineWidth) ? : 1;
          paintBoardView.paintLineColor = lineColor ? : [UIColor blackColor];
          paintBoardView.paintBoardColor = boardColor ? : [UIColor whiteColor];
          paintBoardView.resultBlock = result;
  
          return paintBoardView;
      }
  
      /// 创建简单画板视图控件
      + (instancetype)q_paintBoardViewWithFrame:(CGRect)frame {
  
          QPaintBoardView *paintBoardView = [[self alloc] initWithFrame:frame];
  
          paintBoardView.paintLineWidth = 1;
          paintBoardView.paintLineColor = [UIColor blackColor];
          paintBoardView.paintBoardColor = [UIColor whiteColor];
  
          return paintBoardView;
      }
  
      #pragma mark - 自定义画板
  
      /// 初始化，自定义画板界面
      - (instancetype)init {
  
          if (self = [super init]) {
  
              self.clipsToBounds = YES;
  
              // 添加工具按钮视图
  
              self.toolView = [[UIView alloc] init];
              self.toolView.backgroundColor = [UIColor blackColor];
              [self addSubview:self.toolView];
  
              NSArray *imageNames = @[@"btn_brush", @"btn_board", @"btn_eraser", @"btn_back", @"btn_clear", @"btn_save"];
              NSArray *selectedImageNames = @[@"btn_brush_pressed", @"btn_board_pressed", @"btn_eraser_pressed"];
  
              for (NSUInteger i = 0; i < 6; i++) {
  
                  UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
                  button.tag = i;
                  [button setBackgroundImage:[self q_getBundleImageWithName:imageNames[i]] forState:UIControlStateNormal];
                  [button addTarget:self action:@selector(toolButtonClick:) forControlEvents:UIControlEventTouchUpInside];
                  [self.toolView addSubview:button];
  
                  if (i < 3) {
                      [button setBackgroundImage:[self q_getBundleImageWithName:selectedImageNames[i]] forState:UIControlStateSelected];
                  }
              }
  
              // 添加画笔设置视图
  
              self.brushSetingView = [[UIView alloc] init];
              self.brushSetingView.backgroundColor = [UIColor grayColor];
              [self addSubview:self.brushSetingView];
              [self sendSubviewToBack:self.brushSetingView];
  
              UIView *widthBackView = [[UIView alloc] init];
              widthBackView.layer.borderWidth = 1;
              widthBackView.layer.borderColor = [UIColor lightGrayColor].CGColor;
              UIView *widthView = [[UIView alloc] init];
              [widthBackView addSubview:widthView];
              [self.brushSetingView addSubview:widthBackView];
  
              UISlider *widthSlider = [[UISlider alloc] init];
              widthSlider.thumbTintColor = [UIColor orangeColor];
              [widthSlider addTarget:self action:@selector(widthSliderClick:) forControlEvents:UIControlEventValueChanged];
              [self.brushSetingView addSubview:widthSlider];
  
              UIButton *colorSelectedBtn = [[UIButton alloc] init];
              colorSelectedBtn.layer.borderWidth = 1;
              colorSelectedBtn.layer.borderColor = [UIColor lightGrayColor].CGColor;
              [colorSelectedBtn addTarget:self action:@selector(colorSelectedBtnClick:) forControlEvents:UIControlEventTouchUpInside];
              [self.brushSetingView addSubview:colorSelectedBtn];
  
              // 添加画笔颜色选择视图
  
              self.colorSelectedView = [[UIScrollView alloc] init];
              self.colorSelectedView.backgroundColor = [[UIColor grayColor] colorWithAlphaComponent:0.3];
              self.colorSelectedView.showsHorizontalScrollIndicator = NO;
              [self addSubview:self.colorSelectedView];
              [self sendSubviewToBack:self.colorSelectedView];
  
              NSArray *colorArray = @[[UIColor blackColor], [UIColor whiteColor], [UIColor redColor],
                                      [UIColor greenColor], [UIColor blueColor], [UIColor cyanColor],
                                      [UIColor magentaColor], [UIColor orangeColor], [UIColor yellowColor],
                                      [UIColor darkGrayColor], [UIColor lightGrayColor], [UIColor brownColor],
                                      [UIColor grayColor], [UIColor purpleColor]];
  
              for (NSUInteger i = 0; i < 14; i++) {
                  UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
                  button.layer.borderWidth = 1;
                  button.layer.borderColor = [UIColor lightGrayColor].CGColor;
                  [button setBackgroundColor:colorArray[i]];
                  [button addTarget:self action:@selector(colorSelectedClick:) forControlEvents:UIControlEventTouchUpInside];
                  [self.colorSelectedView addSubview:button];
              }
  
              // 添加画板设置视图
  
              self.boardSetingView = [[UIScrollView alloc] init];
              self.boardSetingView.backgroundColor = [UIColor grayColor];
              self.boardSetingView.showsHorizontalScrollIndicator = NO;
              [self addSubview:self.boardSetingView];
              [self sendSubviewToBack:self.boardSetingView];
  
              for (NSUInteger i = 0; i < 14; i++) {
                  UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
                  button.layer.borderWidth = 1;
                  button.layer.borderColor = [UIColor lightGrayColor].CGColor;
                  [button setBackgroundColor:colorArray[i]];
                  [button addTarget:self action:@selector(boardColorSelectedClick:) forControlEvents:UIControlEventTouchUpInside];
                  [self.boardSetingView addSubview:button];
              }
          }
          return self;
      }
  
      /// 布局子控件
      - (void)layoutSubviews {
          [super layoutSubviews];
  
          if (self.subviews.count) {
  
              // 设置工具按钮视图
  
              self.toolView.frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 44);
  
              for (NSUInteger i = 0; i < 6; i++) {
                  CGFloat margin = (self.bounds.size.width - 44 * 6) / 7;
                  CGFloat x = margin + (margin + 44) * i;
                  self.toolView.subviews[i].frame = CGRectMake(x, 0, 44, 44);
              }
  
              // 设置画笔设置视图
  
              self.brushSetingView.frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 60);
  
              self.brushSetingView.subviews[0].frame = CGRectMake(15, 15, 30, 30);
              self.brushSetingView.subviews[0].layer.cornerRadius = 15;
              self.brushSetingView.subviews[0].layer.masksToBounds = YES;
  
              CGFloat w = self.paintLineWidth;
              self.brushSetingView.subviews[0].subviews[0].frame = CGRectMake(15 - w / 2, 15 - w / 2, w, w);
              self.brushSetingView.subviews[0].subviews[0].layer.cornerRadius = w / 2;
              self.brushSetingView.subviews[0].subviews[0].layer.masksToBounds = YES;
              self.brushSetingView.subviews[0].subviews[0].backgroundColor = self.paintLineColor;
  
              self.brushSetingView.subviews[1].frame = CGRectMake(60, 15, self.bounds.size.width - 60 - 80, 32);
              UISlider *slider = self.brushSetingView.subviews[1];
              slider.value = self.paintLineWidth / 30;
  
              self.brushSetingView.subviews[2].frame = CGRectMake(self.bounds.size.width - 60, 15, 50, 30);
              self.brushSetingView.subviews[2].backgroundColor = self.paintLineColor;
  
              // 设置画笔颜色选择视图
  
              self.colorSelectedView.frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 60);
              self.colorSelectedView.contentSize = CGSizeMake(14 * (50 + 20) + 20, 50);
  
              for (NSUInteger i = 0; i < 14; i++) {
                  CGFloat x = 20 + (20 + 50) * i;
                  self.colorSelectedView.subviews[i].frame = CGRectMake(x, 10, 50, 40);
              }
  
              // 设置画板设置视图
  
              self.boardSetingView.frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 60);
              self.boardSetingView.contentSize = CGSizeMake(14 * (50 + 20) + 20, 50);
  
              for (NSUInteger i = 0; i < 14; i++) {
                  CGFloat x = 20 + (20 + 50) * i;
                  self.boardSetingView.subviews[i].frame = CGRectMake(x, 10, 50, 40);
              }
          }
      }
  
      /// 工具按钮点击事件处理
      - (void)toolButtonClick:(UIButton *)btn {
  
          switch (btn.tag) {
  
              case 0: {
                  // 画笔设置
  
                  [self exitEraseState];
  
                  if (btn.isSelected == NO) {
  
                      [self hideBoardSetingView];
  
                      [self showColorSelectedView];
                      [self showBrushSetingView];
  
                  } else {
  
                      [self hideColorSelectedView];
                      [self hideBrushSetingView];
                  }
                  break;
              }
  
              case 1: {
                  // 画板设置
  
                  [self exitEraseState];
  
                  if (btn.isSelected == NO) {
  
                      [self hideColorSelectedView];
                      [self hideBrushSetingView];
  
                      [self showBoardSetingView];
  
                  } else {
  
                      [self hideBoardSetingView];
                  }
                  break;
              }
  
              case 2: {
                  // 擦除
  
                  [self hideBoardSetingView];
  
                  [self hideColorSelectedView];
                  [self hideBrushSetingView];
  
                  if (btn.selected == NO) {
  
                      [self enterEraseState];
  
                  } else {
                      [self exitEraseState];
                  }
                  break;
              }
  
              case 3: {
                  // 撤销
  
                  [self hideBoardSetingView];
  
                  [self hideColorSelectedView];
                  [self hideBrushSetingView];
  
                  [self q_back];
  
                  break;
              }
  
              case 4: {
                  // 清除
  
                  [self hideBoardSetingView];
  
                  [self hideColorSelectedView];
                  [self hideBrushSetingView];
  
                  [self exitEraseState];
  
                  [self q_clear];
  
                  break;
              }
  
              case 5: {
                  // 获取绘制结果
  
                  [self hideBoardSetingView];
  
                  [self hideColorSelectedView];
                  [self hideBrushSetingView];
  
                  [self exitEraseState];
  
                  if (self.resultBlock) {
                      self.resultBlock([self q_getPaintImage]);
                  }
  
                  break;
              }
  
              default:
                  break;
          }
      }
  
      /// 画笔线宽设置按钮点击事件处理
      - (void)widthSliderClick:(UISlider *)slider {
  
          if (slider.value == 0) {
              self.paintLineWidth = 1;
          } else {
              self.paintLineWidth = slider.value * 30;
          }
  
          CGFloat w = self.paintLineWidth;
          self.brushSetingView.subviews[0].subviews[0].frame = CGRectMake(15 - w / 2, 15 - w / 2, w, w);
          self.brushSetingView.subviews[0].subviews[0].layer.cornerRadius = w / 2;
      }
  
      /// 画笔颜色选择按钮点击事件处理
      - (void)colorSelectedBtnClick:(UIButton *)btn {
  
          if (btn.selected == NO) {
              [self showColorSelectedView];
          } else {
              [self hideColorSelectedView];
          }
      }
  
      /// 画笔颜色选择点击响应事件处理
      - (void)colorSelectedClick:(UIButton *)btn {
  
          self.paintLineColor = btn.backgroundColor;
  
          self.brushSetingView.subviews[0].subviews[0].backgroundColor = btn.backgroundColor;
          self.brushSetingView.subviews[2].backgroundColor = btn.backgroundColor;
      }
  
      /// 画板颜色选择点击响应事件处理
      - (void)boardColorSelectedClick:(UIButton *)btn {
  
          self.paintBoardColor = btn.backgroundColor;
      }
  
      /// 显示画笔设置视图
      - (void)showBrushSetingView {
  
          UIButton *setBrushBtn = self.toolView.subviews[0];
  
          if (setBrushBtn.selected == NO) {
  
              setBrushBtn.selected = YES;
  
              [UIView animateWithDuration:0.2 animations:^{
                  CGRect frame = CGRectMake(0, self.bounds.size.height - 44 - 60, self.bounds.size.width, 60);
                  self.brushSetingView.frame = frame;
              }];
          }
      }
  
      /// 隐藏画笔设置视图
      - (void)hideBrushSetingView {
  
          UIButton *setBrushBtn = self.toolView.subviews[0];
  
          if (setBrushBtn.selected) {
  
              setBrushBtn.selected = NO;
  
              [UIView animateWithDuration:0.2 animations:^{
                  CGRect frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 60);
                  self.brushSetingView.frame = frame;
              }];
          }
      }
  
      // 显示画笔颜色选择视图
      - (void)showColorSelectedView {
  
          UIButton *colorSelectedBtn = self.brushSetingView.subviews[2];
  
          if (colorSelectedBtn.selected == NO) {
  
              colorSelectedBtn.selected = YES;
  
              [UIView animateWithDuration:0.2 animations:^{
                  CGRect frame = CGRectMake(0, self.bounds.size.height - 44 - 60 - 60, self.bounds.size.width, 60);
                  self.colorSelectedView.frame = frame;
              }];
          }
      }
  
      /// 隐藏画笔颜色选择视图
      - (void)hideColorSelectedView {
  
          UIButton *colorSelectedBtn = self.brushSetingView.subviews[2];
  
          if (colorSelectedBtn.selected) {
  
              colorSelectedBtn.selected = NO;
  
              [UIView animateWithDuration:0.2 animations:^{
                  CGRect frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 60);
                  self.colorSelectedView.frame = frame;
              }];
          }
      }
  
      /// 显示画板设置视图
      - (void)showBoardSetingView {
  
          UIButton *setBoardBtn = self.toolView.subviews[1];
  
          if (setBoardBtn.selected == NO) {
  
              setBoardBtn.selected = YES;
  
              [UIView animateWithDuration:0.2 animations:^{
                  CGRect frame = CGRectMake(0, self.bounds.size.height - 44 - 60, self.bounds.size.width, 60);
                  self.boardSetingView.frame = frame;
              }];
          }
      }
  
      /// 隐藏画板设置视图
      - (void)hideBoardSetingView {
  
          UIButton *setBoardBtn = self.toolView.subviews[1];
  
          if (setBoardBtn.selected) {
  
              setBoardBtn.selected = NO;
  
              [UIView animateWithDuration:0.2 animations:^{
                  CGRect frame = CGRectMake(0, self.bounds.size.height - 44, self.bounds.size.width, 60);
                  self.boardSetingView.frame = frame;
              }];
          }
      }
  
      /// 进入擦除状态
      - (void)enterEraseState {
  
          UIButton *setEraseBtn = self.toolView.subviews[2];
  
          if (setEraseBtn.selected == NO) {
  
              setEraseBtn.selected = YES;
  
              self.lastPaintLineColor = self.paintLineColor;
              self.paintLineColor = self.paintBoardColor;
  
              self.lastPaintLineWidth = self.paintLineWidth;
              self.paintLineWidth = self.paintLineWidth + 5;
          }
      }
  
      /// 退出擦除状态
      - (void)exitEraseState {
  
          UIButton *setEraseBtn = self.toolView.subviews[2];
  
          if (setEraseBtn.isSelected) {
  
              setEraseBtn.selected = NO;
  
              self.paintLineColor = self.lastPaintLineColor;
              self.paintLineWidth = self.lastPaintLineWidth;
          }
      }
  
      #pragma mark - 绘制图案
  
      /// 触摸开始
      - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
  
          if (self.subviews.count) {
  
              [self hideColorSelectedView];
              [self hideBrushSetingView];
              [self hideBoardSetingView];
          }
  
          // 获取触摸起始点位置
          CGPoint startPoint = [touches.anyObject locationInView:self];
  
          // 添加路径描绘起始点
          [self.path moveToPoint:startPoint];
  
          // 记录线的属性
          self.path.pathColor = self.paintLineColor;
          self.path.pathWidth = self.paintLineWidth;
  
          // 添加一条触摸路径描绘
          [self.pathsArrayM addObject:self.path];
      }
  
      /// 触摸移动
      - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
  
          // 获取触摸点位置
          CGPoint touchPoint = [touches.anyObject locationInView:self];
  
          // 添加路径描绘
          [self.path addLineToPoint:touchPoint];
  
          // 刷新视图
          [self setNeedsDisplay];
      }
  
      /// 触摸结束
      - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
  
          // 销毁 path
          self.path = nil;
      }
  
      /// 触摸取消
      - (void)touchesCancelled:(NSSet *)touches withEvent:(nullable UIEvent *)event {
          [self touchesEnded:touches withEvent:event];
      }
  
      /// 绘制图形，只要调用 drawRect 方法就会把之前的内容全部清空
      - (void)drawRect:(CGRect)rect {
  
          for (QPaintBoardPath *path in self.pathsArrayM) {
  
              // 绘制路径
              path.lineWidth = path.pathWidth;
              [path.pathColor setStroke];
  
              path.lineCapStyle = kCGLineCapRound;
              path.lineJoinStyle = kCGLineJoinRound;
              [path stroke];
          }
      }
  
      /// 获取绘画结果
      - (UIImage * _Nullable)q_getPaintImage {
  
          UIImage *image = nil;
  
          CGSize boardSize = self.bounds.size;
  
          if (self.subviews.count) {
              boardSize.height = self.bounds.size.height - 44;
          }
  
          if (self.pathsArrayM.count) {
              UIGraphicsBeginImageContextWithOptions(boardSize, NO, 0);
              CGContextRef ctx = UIGraphicsGetCurrentContext();
              [self.layer renderInContext:ctx];
              image = UIGraphicsGetImageFromCurrentImageContext();
              UIGraphicsEndImageContext();
          }
  
          return image;
      }
  
      /// 清除绘画结果
      - (void)q_clear {
  
          if (self.pathsArrayM.count) {
              [self.pathsArrayM removeAllObjects];
  
              [self setNeedsDisplay];
          }
      }
  
      /// 撤销绘画结果
      - (void)q_back {
  
          if (self.pathsArrayM.count) {
              [self.pathsArrayM removeLastObject];
  
              [self setNeedsDisplay];
          }
      }
  
      /// 懒加载
  
      - (QPaintBoardPath * _Nullable)path {
  
          // path 每次绘制完成后需要销毁，否则无法清除之前绘制的路径
  
          if (_path == nil) {
              _path = [QPaintBoardPath bezierPath];
          }
          return _path;
      }
  
      - (NSMutableArray *)pathsArrayM {
  
          if (_pathsArrayM == nil) {
              _pathsArrayM = [NSMutableArray array];
          }
          return _pathsArrayM;
      }
  
      /// 设置属性值
      - (void)setPaintBoardColor:(UIColor *)paintBoardColor {
          _paintBoardColor = paintBoardColor;
          self.backgroundColor = paintBoardColor;
      }
  
      /// 加载 bundle 中的图片
      - (UIImage *)q_getBundleImageWithName:(NSString *)name {
  
          NSString *bundlePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"QPaintBoardView.bundle"];
  
          UIImage *image = [[UIImage imageWithContentsOfFile:[bundlePath stringByAppendingPathComponent:name]]
                            imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
          return image;
      }
  
      @end

• 1、创建简单画板

      // 创建简单画板
      CGRect frame = CGRectMake(20, 50, self.view.bounds.size.width - 40, 200);
  
      QPaintBoardView *paintBoardView = [QPaintBoardView q_paintBoardViewWithFrame:frame];
  
      // 可选属性值设置
      paintBoardView.paintLineWidth = 5;                         // default is 1
      paintBoardView.paintLineColor = [UIColor redColor];        // default is blackColor
      paintBoardView.paintBoardColor = [UIColor cyanColor];      // default is whiteColor
  
      [self.view addSubview:paintBoardView];
      self.paintBoardView = paintBoardView;
  
      // 撤销绘画结果
      [self.paintBoardView q_back];
  
      // 清除绘画结果
      [self.paintBoardView q_clear];
  
      // 获取绘画结果
      UIImage *image = [self.paintBoardView q_getPaintImage];

  • 效果

    

• 2、创建画板

      // 创建画板
      QPaintBoardView *paintBoard = [QPaintBoardView q_paintBoardViewWithFrame:self.view.bounds
                                                                     lineWidth:0
                                                                     lineColor:nil
                                                                    boardColor:nil
                                                                   paintResult:^(UIImage * _Nullable image) {
  
          if (image) {
              NSData *data = UIImagePNGRepresentation(image);
              [data writeToFile:@"/Users/JHQ0228/Desktop/Images/pic.png" atomically:YES];
          }
      }];
  
      [self.view addSubview:paintBoard];

  • 效果