ios - 如何在 UIImageView 的左上角和右下角创建 UIButton

Question

我希望在 imageview 的左上角和右下角创建删除按钮。但它看起来不像我需要的。

我希望两个按钮都应该放在红色边框的角落

要创建按钮，我使用了下面的代码

   UIImageView * tappedView = (UIImageView *)[recognizer view];

[tappedView.layer setBorderColor: [[UIColor redColor] CGColor]];
[tappedView.layer setBorderWidth: 2.0];
tappedView.layer.cornerRadius = 10;
tappedView.layer.masksToBounds = NO;


UIButton *deleteBtn = [UIButton buttonWithType:UIButtonTypeCustom];
deleteBtn.frame = CGRectMake(0, 0, 20, 20);

[deleteBtn setImage:[UIImage imageNamed:@"close.png"]forState:UIControlStateNormal];

deleteBtn.layer.shadowColor = [[UIColor blackColor] CGColor];
deleteBtn.layer.shadowOffset = CGSizeMake(0,4);
deleteBtn.layer.shadowOpacity = 0.3;
[tappedView addSubview:deleteBtn];
[deleteBtn addTarget:self action:@selector(deleteProperties:) forControlEvents:UIControlEventTouchUpInside];



UIButton *zoomBtn = [UIButton buttonWithType:UIButtonTypeCustom];
zoomBtn.frame = CGRectMake(tappedView.frame.size.width, tappedView.frame.size.height, 20, 20);

[zoomBtn setImage:[UIImage imageNamed:@"close.png"]forState:UIControlStateNormal];

zoomBtn.layer.shadowColor = [[UIColor blackColor] CGColor];
zoomBtn.layer.shadowOffset = CGSizeMake(0,4);
zoomBtn.layer.shadowOpacity = 0.3;
[tappedView addSubview:zoomBtn];
[zoomBtn addTarget:self action:@selector(ZoomIn:) forControlEvents:UIControlEventTouchUpInside];

请指导我。

我想要这样

Answer 1

只需使用按钮的框架：例如

deleteBtn.frame = CGRectMake(-5, -5, 20, 20);

和

zoomBtn.frame = CGRectMake(tappedView.frame.size.width - 20, tappedView.frame.size.height - 20, 20, 20);

因为前 2 个数字是坐标 x 和 y，并且框架相对于包含的视图框架。

Answer 2

只需使用 zoomBtn.center 而不是 zoomBtn.frame - 这样，您不必考虑按钮的大小 - 它适用于任何大小的按钮。

// Create the button's frame - doesn't matter the x & y
CGRect btnFrame = CGRectMake(0.0f, 0.0f, 20.0f, 20.0f);

zoomBtn.frame = btnFrame;

// Set the zoomBtn center to the bottom right corner
zoomBtn.center = CGPointMake(tappedView.frame.size.width, tappedView.frame.size.height);

deleteBtn.frame = btnFrame;

// Set the deleteBtn center to the top left corner
deleteBtn.center = CGPointMake(0.0f, 0.0f);