objective-c - 显示 "screenshot flash"作为对用户的反馈

Question

我是 Objective-C 的新手，刚刚从头开始制作我的第一个应用程序。这是一个拼写应用程序，如果用户输入了错误的字母，我想显示屏幕上显示的相同白色闪光灯。我该怎么做？

Answer 1

// Create a empty view with the color white.

UIView *flashView = [[UIView alloc] initWithFrame:window.bounds];
flashView.backgroundColor = [UIColor whiteColor];
flashView.alpha = 1.0;

// Add the flash view to the window

[window addSubview:flashView];

// Fade it out and remove after animation.

[UIView animateWithDuration:0.05 animations:^{     flashView.alpha = 0.0;    }      completion:^(BOOL finished) {    [flashView removeFromSuperview];     }     ];