28、Cocoa开发：文本处理、视图操作与开发要点

Cocoa开发：文本处理、视图操作与开发要点

文本排列与居中显示

在视图中，文本块的排列可通过对齐方式、行间距和缩进等属性来实现。以下是在属性字符串中实现文本居中的示例代码：

[[NSColor colorWithDeviceRed: 168.0 / 255.0
                       green: 128.0 / 255.0
                        blue:   0.0 / 255.0
                       alpha: 255.0 / 255.0] set];
NSRectFill ( self.bounds );
NSString* text = @"Centered Text.";
NSMutableDictionary* attributes = [NSMutableDictionary dictionary];
[attributes setObject: [NSFont fontWithName:@"Helvetica" size:85.0]
               forKey: NSFontAttributeName];
[attributes setObject: [NSColor yellowColor]
               forKey: NSForegroundColorAttributeName];
// center text with paragraph style.
NSMutableParagraphStyle* centerStyle = [[NSMutableParagraphStyle alloc] init];