iOS在WKWebView中加载页面时自动弹出软键盘

桃扇骨 2022-11-13 04:12 681阅读 0赞

### 实现方式(UIWebView) ###

首先需要web端设置input为focus聚焦状态，然后设置UIWebView的keyboardDisplayRequiresUserAction属性，默认为YES。如果设置为YES，用户必须明确的点击页面上的元素来显示键盘；如果设置为NO，则进入web页面会自动弹出键盘。

### 实现方式(WKWebView) ###

目前我们基本都用WKWebView来代替UIWebView，因为WKWebView与UIWebView相比较，拥有更快的加载速度和性能，更低的内存占用，更加细致的委托协议配置。但是WKWebView并没有UIWebView的keyboardDisplayRequiresUserAction属性，那就只能通过runtime处理了(同时也需要web端设置input为focus聚焦状态)，如下：

##### 一、导入runtime头文件 #####

#import <objc/runtime.h>

##### 二、在使用了WKWebView的Controller中添加方法 #####

- (void)allowDisplayingKeyboardWithoutUserAction {
        Class class = NSClassFromString(@"WKContentView");
        NSOperatingSystemVersion iOS_11_3_0 = (NSOperatingSystemVersion){11, 3, 0};
        NSOperatingSystemVersion iOS_12_2_0 = (NSOperatingSystemVersion){12, 2, 0};
        NSOperatingSystemVersion iOS_13_0_0 = (NSOperatingSystemVersion){13, 0, 0};
        if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_13_0_0]) {
            SEL selector = sel_getUid("_elementDidFocus:userIsInteracting:blurPreviousNode:activityStateChanges:userObject:");
            Method method = class_getInstanceMethod(class, selector);
            IMP original = method_getImplementation(method);
            IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
                ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
            });
            method_setImplementation(method, override);
        }else if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_12_2_0]) {
            SEL selector = sel_getUid("_elementDidFocus:userIsInteracting:blurPreviousNode:changingActivityState:userObject:");
            Method method = class_getInstanceMethod(class, selector);
            IMP original = method_getImplementation(method);
            IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
                ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
            });
            method_setImplementation(method, override);
        }else if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_11_3_0]) {
            SEL selector = sel_getUid("_startAssistingNode:userIsInteracting:blurPreviousNode:changingActivityState:userObject:");
            Method method = class_getInstanceMethod(class, selector);
            IMP original = method_getImplementation(method);
            IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
                ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
            });
            method_setImplementation(method, override);
        } else {
            SEL selector = sel_getUid("_startAssistingNode:userIsInteracting:blurPreviousNode:userObject:");
            Method method = class_getInstanceMethod(class, selector);
            IMP original = method_getImplementation(method);
            IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, id arg3) {
                ((void (*)(id, SEL, void*, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3);
            });
            method_setImplementation(method, override);
        }
    }

##### 三、在Controller的viewDidLoad方法中调用 #####

[self allowDisplayingKeyboardWithoutUserAction];

#### 现在进入web页面即会自动弹出软键盘了~ ####

参考:[Stack Overflow][]

[Stack Overflow]: https://stackoverflow.com/questions/32449870/programmatically-focus-on-a-form-in-a-webview-wkwebview/48623286#48623286