如何使用内部阴影创建圆角UITextField

Question

我正在定制一个UITextfield看起来像一个UISearchbar.

我做的事情

self.back_textfield = [[UITextField alloc]initWithFrame:CGRectMake(5, 7, 310, 30)];
[self.back_textfield setBorderStyle:UITextBorderStyleRoundedRect];
self.back_textfield.layer.cornerRadius = 15.0;

但我明白这一点:

正如您所看到的,内部阴影不会跟随边界.

Answer 1

我猜a UITextField上的背景是一个图像,所以它没有跟随你的角半径.
在iOS中创建内部阴影很棘手.你有2个选择.
1)使用图像作为背景UITextField
2)以编程方式设置阴影(但它看起来不如选项1吸引人).

以下是使用@Matt Wilding的解决方案为文本字段设置圆形内部阴影的代码

_textField.layer.cornerRadius = 10.0f;

CAShapeLayer* shadowLayer = [CAShapeLayer layer];
[shadowLayer setFrame:_textField.bounds];

// Standard shadow stuff
[shadowLayer setShadowColor:[[UIColor colorWithWhite:0 alpha:1] CGColor]];
[shadowLayer setShadowOffset:CGSizeMake(0.0f, 0.0f)];
[shadowLayer setShadowOpacity:1.0f];
[shadowLayer setShadowRadius:4];

// Causes the inner region in this example to NOT be filled.
[shadowLayer setFillRule:kCAFillRuleEvenOdd];

// Create the larger rectangle path.
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddRect(path, NULL, CGRectInset(_textField.bounds, -42, -42));

// Add the inner path so it's subtracted from the outer path.
// someInnerPath could be a simple bounds rect, or maybe
// a rounded one for some extra fanciness.
CGPathRef someInnerPath = [UIBezierPath bezierPathWithRoundedRect:_textField.bounds cornerRadius:10.0f].CGPath;
CGPathAddPath(path, NULL, someInnerPath);
CGPathCloseSubpath(path);

[shadowLayer setPath:path];
CGPathRelease(path);

[[_textField layer] addSublayer:shadowLayer];

CAShapeLayer* maskLayer = [CAShapeLayer layer];
[maskLayer setPath:someInnerPath];
[shadowLayer setMask:maskLayer];

别忘了导入

#import <QuartzCore/QuartzCore.h>