iOS 11 使用两种方法替换(Method Swizzling)去掉导航栏返回按钮的文字

这篇文章主要介绍了iOS 11 使用方法替换(Method Swizzling)去掉导航栏返回按钮的文字,需要的朋友可以参考下

方法一：设置barbuttonitem的文本样式为透明颜色，代码如下：

1 2	`[[uibarbuttonitem appearance] settitletextattributes:@{nsforegroundcolorattributename: [uicolor clearcolor]} forstate:uicontrolstatenormal];` `[[uibarbuttonitem appearance] settitletextattributes:@{nsforegroundcolorattributename: [uicolor clearcolor]} forstate:uicontrolstatehighlighted];`

此外这种方法会导致title不能居中，被偏移很多，如下所示（虽然不被显示，也占了导航栏左边很大一部分位置）

iOS 11 使用两种方法替换(Method Swizzling)去掉导航栏返回按钮的文字

方法二：给uiviewcontroller添加类别，然后在load方法里面用method swzilling方法替换交换viewdidappear，部分代码如下

									+(void)load {

									  swizzlemethod([self class], @selector(viewdidappear:), @selector(ac_viewdidappear));

									}

									- (void)ac_viewdidappear{

									  self.navigationitem.backbarbuttonitem = [[uibarbuttonitem alloc]

									                       initwithtitle:@""

									                       style:uibarbuttonitemstyleplain

									                       target:self

									                       action:nil];

									  [self ac_viewdidappear];

									}

									void swizzlemethod(class class, sel originalselector, sel swizzledselector)

									{

									  // the method might not exist in the class, but in its superclass

									  method originalmethod = class_getinstancemethod(class, originalselector);

									  method swizzledmethod = class_getinstancemethod(class, swizzledselector);

									  // class_addmethod will fail if original method already exists

									  bool didaddmethod = class_addmethod(class, originalselector, method_getimplementation(swizzledmethod), method_gettypeencoding(swizzledmethod));

									  // the method doesn't exist and we just added one

									  if (didaddmethod) {

									    class_replacemethod(class, swizzledselector, method_getimplementation(originalmethod), method_gettypeencoding(originalmethod));

									  }

									  else {

									    method_exchangeimplementations(originalmethod, swizzledmethod);

									  }

									}