UIToolBar使用技巧 ( 设置UIBarButtonItem 之间的间距，居中对齐 )

可以在toolBar上添加任何View。其实它的原理是把你要添加的View先加到UIBarButtonItem里面，最后再把UIBarButtonItem数组一次性放到toolbar的items里面。

toolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
 
 toolBar.barStyle = UIBarStyleDefault;
 
  
 
 UIBarButtonItem *titleButton = [[UIBarButtonItem alloc] initWithTitle:title 
 
                                                                         style: UIBarButtonItemStylePlain 
 
                                                                        target: nil 
 
                                                                        action: nil];
 
         
 
 UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithTitle:@"完成" 
 
                                                                         style: UIBarButtonItemStyleDone 
 
                                                                        target: self 
 
                                                                        action: @selector(done)];
 
         
 
 //UIBarButtonItem *leftButton  = [[UIBarButtonItem alloc] initWithTitle:@"取消" 
 
 //                                                                        style: UIBarButtonItemStyleBordered 
 
 //                                                                       target: self 
 
 //                                                                       action: @selector(docancel)];
 
         
 
 UIBarButtonItem *fixedButton  = [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemFlexibleSpace 
 
                                                                                       target: nil 
 
                                                                                       action: nil];
 
         
 
 NSArray *array = [[NSArray alloc] initWithObjects:fixedButton,fixedButton, titleButton,fixedButton, rightButton, nil];
 
 [toolBar setItems: array];
 
 [titleButton release];
 
 //[leftButton  release];
 
 [rightButton release];
 
 [fixedButton release];
 
 [array       release];

通过 填充   fixedButton   来实现