我们通过一些 Objective C 运行时技巧来删除这个栏。
我们有一个类,它有一个方法:
@interface _SwizzleHelper : NSObject @end
@implementation _SwizzleHelper
-(id)inputAccessoryView
{
return nil;
}
@end
一旦我们有了一个想要从中删除栏的 Web 视图,我们就迭代其滚动视图的子视图并获取UIWebDocumentView
班级。然后,我们动态地将上面创建的类的超类设为子视图的类(UIWebDocumentView - 但我们不能预先这么说,因为这是私有 API),并将子视图的类替换为我们的类。
#import "objc/runtime.h"
-(void)__removeInputAccessoryView
{
UIView* subview;
for (UIView* view in self.scrollView.subviews) {
if([[view.class description] hasPrefix:@"UIWeb"])
subview = view;
}
if(subview == nil) return;
NSString* name = [NSString stringWithFormat:@"%@_SwizzleHelper", subview.class.superclass];
Class newClass = NSClassFromString(name);
if(newClass == nil)
{
newClass = objc_allocateClassPair(subview.class, [name cStringUsingEncoding:NSASCIIStringEncoding], 0);
if(!newClass) return;
Method method = class_getInstanceMethod([_SwizzleHelper class], @selector(inputAccessoryView));
class_addMethod(newClass, @selector(inputAccessoryView), method_getImplementation(method), method_getTypeEncoding(method));
objc_registerClassPair(newClass);
}
object_setClass(subview, newClass);
}
与 Swift 3.0 中的上述内容等效:
import UIKit
import ObjectiveC
var swizzledClassMapping = [AnyClass]()
extension UIWebView {
func noInputAccessoryView() -> UIView? {
return nil
}
public func removeInputAccessoryView() {
var subview: AnyObject?
for (_, view) in scrollView.subviews.enumerated() {
if NSStringFromClass(type(of: view)).hasPrefix("UIWeb") {
subview = view
}
}
guard subview != nil else {
return
}
//Guard in case this method is called twice on the same webview.
guard !(swizzledClassMapping as NSArray).contains(type(of: subview!)) else {
return;
}
let className = "\type(of: subview!)_SwizzleHelper"
var newClass : AnyClass? = NSClassFromString(className)
if newClass == nil {
newClass = objc_allocateClassPair(type(of: subview!), className, 0)
guard newClass != nil else {
return;
}
let method = class_getInstanceMethod(type(of: self), #selector(UIWebView.noInputAccessoryView))
class_addMethod(newClass!, #selector(getter: UIResponder.inputAccessoryView), method_getImplementation(method), method_getTypeEncoding(method))
objc_registerClassPair(newClass!)
swizzledClassMapping += [newClass!]
}
object_setClass(subview!, newClass!)
}
}