ios 多點觸 遍曆

標籤：

案例：根據多點觸控用圖片來繪製路徑 和 清除路徑。

主要擷取座標 設定imageview的座標。

視圖預設不支援 多點觸控：設定為支援多點觸控：[self.view  setMultipleTouchEnabled:YES];

1.迴圈建立imageView

 4 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 5 { 6     NSInteger i = 0; 7     for (UITouch *touch in touches) { 8         UIImageView *imageview = [[UIImageView alloc]initWithImage:self.imageData[i]]; 9         CGPoint location = [touch locationInView:self.view];10         [imageview setCenter:location];11         [self.view addSubview:imageview];12         i++;13     }14 }

 

2.清除self.view

isKindOfClass：  來判斷是什麼類型的控制項。

 1         [imageview setCenter:location]; 2         [self.view addSubview:imageview]; 3         i++; 4     } 5 } 6  7 - (void)clearView 8 { 9     for (UIImageView *imageView in self.view.subviews) {10         11         if ([imageView isKindOfClass:[UIImageView class]]) {12             [UIView animateWithDuration:5.0f animations:^{13                 [imageView setAlpha:0.1f];14             } completion:^(BOOL finished) {15                 [imageView removeFromSuperview];16             }] ;17         }18     }19 }

 

ios 多點觸 遍曆