ios – 如何在UIToolbar中沿长度分配按钮？

在我的应用程序中,我使用一些代码,动态地将带有图像的按钮添加到UIToolbar：

[self.navigationController setToolbarHidden:NO];
UIImage *buttonImage1 = [UIImage imageNamed:@"1.png"];
UIImage *buttonImage2 = [UIImage imageNamed:@"2.png"];
UIImage *buttonImage3 = [UIImage imageNamed:@"3.png"];

UIBarButtonItem *toolButton1 = [[UIBarButtonItem alloc] initWithImage:buttonImage1 style:UIBarButtonItemStylePlain target:self action:@selector(btnSettingsClick:)];
UIBarButtonItem *toolButton2= [[UIBarButtonItem alloc] initWithImage:buttonImage2 style:UIBarButtonItemStylePlain target:self action:@selector(btnSettingsClick:)];
UIBarButtonItem *toolButton3 = [[UIBarButtonItem alloc] initWithImage:buttonImage3 style:UIBarButtonItemStylePlain target:self action:@selector(btnSettingsClick:)];

[self settoolbaritems:[NSArray arrayWithObjects:toolButton1,toolButton2,toolButton3,nil]];

但它运作不佳：

如果我尝试设置另一个按钮样式：

toolButton1.style = UIBarButtonSystemItemFlexibleSpace;
toolButton2.style = UIBarButtonSystemItemFlexibleSpace;
toolButton3.style = UIBarButtonSystemItemFlexibleSpace;

它看起来也很差：

我怎样才能解决这个问题？

解决方法

添加两个使用系统样式UIBarButtonSystemItemFlexibleSpace的附加栏按钮,并在每个现有按钮之间放置一个：

[self.navigationController setToolbarHidden:NO];
UIImage *buttonImage1 = [UIImage imageNamed:@"1"];
UIImage *buttonImage2 = [UIImage imageNamed:@"2"];
UIImage *buttonImage3 = [UIImage imageNamed:@"3"];

UIBarButtonItem *toolButton1 = [[UIBarButtonItem alloc] initWithImage:buttonImage1 style:UIBarButtonItemStylePlain target:self action:@selector(btnSettingsClick:)];
UIBarButtonItem *toolButton2= [[UIBarButtonItem alloc] initWithImage:buttonImage2 style:UIBarButtonItemStylePlain target:self action:@selector(btnSettingsClick:)];
UIBarButtonItem *toolButton3 = [[UIBarButtonItem alloc] initWithImage:buttonImage3 style:UIBarButtonItemStylePlain target:self action:@selector(btnSettingsClick:)];

[self settoolbaritems:[NSArray arrayWithObjects:
    toolButton1,[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil],nil]];

概念化是很奇怪的,但灵活空间实际上是一个独特的对象,而不是应用于其他对象的样式.