OC與JS互動 -- 原生
阿新 • • 發佈:2019-02-14
本文只是介紹簡單的OC與JS互動
一、OC呼叫JS
<html>
<header>
<meta http-equiv="Content-Type" content="text/html"; charset="UTF-8"/>
<title>zhaoName製作的網頁</title>
</header>
<script Type = "text/javascript">
function login()
{
return 100;
}
</script>
<body>
電話:10086
<button style="background:red; width:120px; height:30px;">call</button>
</body>
</html>
呼叫webView的方法
// 獲取網頁的標題
self.title = [webView stringByEvaluatingJavaScriptFromString:@"document.title"];
// 呼叫JS中的函式
NSLog(@"%@", [webView stringByEvaluatingJavaScriptFromString:@"login();"]);
該方法返回一個字串,注意它是一個同步方法,若使用它執行非常耗時的操作會導致介面的卡頓。有兩個解決方案:
1>使用官方推薦webView方法evaluateJavaScript:completionHandler:
2>自定義一個延遲執行方法來防止阻塞,或將方法放到setTimeout 中
二、JS呼叫OC
<html>
<header>
<meta http-equiv ="Content-Type" content="text/html"; charset="UTF-8"/>
<title>zhaoName製作的網頁</title>
</header>
<script Type = "text/javascript">
function login()
{
location.href = 'zhaoName://openLibrary';
}
</script>
<body>
電話:10086
<button style="background:red; width:120px; height:30px;" onclick="login();">call</button>
<br>
<a href="https://github.com/zhaoName">zhaoName的Git</a>
</body>
</html>
以下都是點選webView上的按鈕”call”,呼叫OC中的方法
1、沒有引數
/**
* 通過這個方法完成JS調OC
*/
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSString *url = @"zhaoname://";
if ([request.URL.absoluteString hasPrefix:url])
{
NSString *methodName = [request.URL.absoluteString substringFromIndex:url.length];
[self performSelector:NSSelectorFromString(methodName) withObject:nil];
return NO;
}
NSLog(@"想載入網路請求,不想做JS呼叫OC");
return YES;
}
- (void)openLibrary
{
NSLog(@"JS呼叫OC方法--%s", __func__);
}
2、一個引數
上面HTML中函式修改為
function login()
{
location.href = 'zhaoName://sendMessage_?How are you';
}
OC獲取的路徑path會自動刪除’:’,所以此處用’_’代替。引數用?分割。(實際開發中需要你和寫HTML的人共同制定JS調OC的規則)
/**
* 通過這個方法完成JS掉OC
*/
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSString *url = @"zhaoname://";
if ([request.URL.absoluteString hasPrefix:url])
{
// 路徑
NSString *path = [request.URL.absoluteString substringFromIndex:url.length];
NSArray *subPaths = [path componentsSeparatedByString:@"?"];
// 獲取方法名
NSString *methodName = [subPaths.firstObject stringByReplacingOccurrencesOfString:@"_" withString:@":"];
// 引數
NSString *para = subPaths.lastObject;
[self performSelector:NSSelectorFromString(methodName) withObject:para];
return NO;
}
NSLog(@"想載入網路請求,不想做JS呼叫OC");
return YES;
}
- (void)sendMessage:(NSString *)message
{
NSLog(@"JS呼叫OC方法--%s 引數:%@", __func__, message);
}
3、兩個引數
上面HTML中函式修改為
function login()
{
location.href = 'zhaoName://sendMessage_sendName_?hehe&zhaoName';
}
‘:’用’_’代替,方法名和引數用’?’分割,引數之間用’&’分割
/**
* 通過這個方法完成JS掉OC
*/
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSString *url = @"zhaoname://";
if ([request.URL.absoluteString hasPrefix:url])
{
// 路徑
NSString *path = [request.URL.absoluteString substringFromIndex:url.length];
NSArray *subPaths = [path componentsSeparatedByString:@"?"];
// 獲取方法名
NSString *methodName = [subPaths.firstObject stringByReplacingOccurrencesOfString:@"_" withString:@":"];
// 引數
NSArray *paras = nil;
// 防止出現無引數的情況
if(subPaths.count == 2 || [subPaths.lastObject containsString:@"&"])
{
paras = [subPaths.lastObject componentsSeparatedByString:@"&"];
}
// 防止出現引數為空的情況
NSString *firstPara = paras.firstObject;
NSString *secondPara = paras.count <= 1 ? nil : paras.lastObject;
[self performSelector:NSSelectorFromString(methodName) withObject:firstPara withObject:secondPara];
return NO;
}
NSLog(@"想載入網路請求,不想做JS呼叫OC");
return YES;
}
- (void)sendMessage:(NSString *)message sendName:(NSString *)sendName
{
NSLog(@"JS呼叫OC方法--%s 引數:%@ %@", __func__, message, sendName);
}
4、三個及以上的引數
系統自帶的方法performSelector最多隻能傳兩個引數,所以有三個及以上的引數我們要藉助NSInvocation類。
NSObject+Invocation.h檔案
#import <Foundation/Foundation.h>
@interface NSObject (Invocation)
/**
* 基於NSObject封裝一個可用於JS呼叫OC方法的分類,適用於引數可有可無,可有多個
@param selector 方法名
@param parameters 引數
@return 返回值
*/
- (id)performSelector:(SEL)selector withParameters:(NSArray *)parameters;
@end
NSObject+Invocation.m檔案
#import "NSObject+Invocation.h"
@implementation NSObject (Invocation)
- (id)performSelector:(SEL)selector withParameters:(NSArray *)parameters
{
// 方法簽名
NSMethodSignature *signature = [[self class] instanceMethodSignatureForSelector:selector];
if(signature == nil) return nil;
// 利用NSIvocation可以包裝一次方法呼叫(設定方法呼叫者、方法名、引數、返回值)
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
// 設定方法呼叫者
invocation.target = self;
// 設定方法名
invocation.selector = selector;
// 設定方法引數 注意引數下標從2開始,0、1被系統佔用
for(int i=0; i<parameters.count; i++)
{
id object = parameters[i];
if([object isKindOfClass:[NSNull class]]) continue;
[invocation setArgument:&object atIndex:i+2];
}
// 執行
[invocation invoke];
// 設定返回值
id returnValue = nil;
// 兼顧沒有返回值的方法
if(signature.methodReturnLength != 0)
{
[invocation getReturnValue:&returnValue];// 說明此方法有返回值
}
return returnValue;
}
@end
上面HTML中函式修改為
function login()
{
location.href = 'zhaoName://sendMessage_sendName_reviceName_?hehe&zhaoName&nicai';
}
/**
* 通過這個方法完成JS掉OC
*/
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSString *url = @"zhaoname://";
if ([request.URL.absoluteString hasPrefix:url])
{
// 路徑
NSString *path = [request.URL.absoluteString substringFromIndex:url.length];
NSArray *subPaths = [path componentsSeparatedByString:@"?"];
// 獲取方法名
NSString *methodName = [subPaths.firstObject stringByReplacingOccurrencesOfString:@"_" withString:@":"];
// 引數
NSArray *paras = [subPaths.lastObject componentsSeparatedByString:@"&"];
// 呼叫OC中的方法 並獲取返回值
NSString *result = [self performSelector:NSSelectorFromString(methodName) withParameters:paras];
NSLog(@"%@", result);
return NO;
}
NSLog(@"想載入網路請求,不想做JS呼叫OC");
return YES;
}
- (NSString *)sendMessage:(NSString *)message sendName:(NSString *)sendName reviceName:(NSString *)reviceName
{
NSLog(@"JS呼叫OC方法--%s 引數:%@ %@ %@", __func__, message, sendName, reviceName);
return @"發信息";
}