http://blog.csdn.net/duzixi/article/details/36047201
尤其是UIWebView类的 stringByEvaluatingJavaScriptFromString 方法
让很多人觉得又得学一种新的语言。
而这一部分也是项目中学生常问的问题之一。
本文以Category(类目)的方式扩展了UIWebView类,将一些常用的JavaScript操作封装成UIWebView类方法。
最新源代码下载地址:https://github.com/duzixi/UIWebView-HTML5(持续维护)
头文件(UIWebView+HTML5.h)
class="brush:objc;gutter:false;">// // UIWebView+HTML5.h // WebViewJS // // Created by 杜子兮(duzixi) on 14-6-30. // Edited by 杜子兮(duzixi) on 14-7-11. 修改网页图片显示大小 // 添加(jQuery) // Copyright (c) 2014年 lanou3g.com 蓝鸥. All rights reserved. // #import <UIKit/UIKit.h> @interface UIWebView (JavaScript) #pragma mark - #pragma mark 获取网页中的数据 /// 获取某个标签的结点个数 - (int)nodeCountOfTag:(NSString *)tag; /// 获取当前页面URL - (NSString *) getCurrentURL; /// 获取标题 - (NSString *) getTitle; /// 获取图片 - (NSArray *) getImgs; /// 获取当前页面所有链接 - (NSArray *) getOnClicks; #pragma mark - #pragma mark 改变网页样式和行为 /// 改变背景颜色 - (void) setBackgroundColor:(UIColor *)color; /// 为所有图片添加点击事件(网页中有些图片添加无效) - (void) addClickEventOnImg; /// 改变所有图像的宽度 - (void) setImgWidth:(int)size; /// 改变所有图像的高度 - (void) setImgHeight:(int)size; /// 改变指定标签的字体颜色 - (void) setFontColor:(UIColor *) color withTag:(NSString *)tagName; /// 改变指定标签的字体大小 - (void) setFontSize:(int) size withTag:(NSString *)tagName; @end
实现文件(UIWebView+HTML5.m):
// // UIWebView+HTML5.m // // Created by 杜子兮(duzixi) on 14-6-30. // Edited by 杜子兮(duzixi) on 14-7-11. 修改网页图片显示大小 // 添加(jQuery) // Copyright (c) 2014年 lanou3g.com 蓝鸥. All rights reserved. // #import "UIWebView+HTML5.h" #import "UIColor+Change.h" @implementation UIWebView (JavaScript) #pragma mark - #pragma mark 获取网页中的数据 /// 获取某个标签的结点个数 - (int)nodeCountOfTag:(NSString *)tag { NSString *jsString = [NSString stringWithFormat:@"document.getElementsByTagName('%@').length", tag]; int len = [[self stringByEvaluatingJavaScriptFromString:jsString] intValue]; return len; } /// 获取当前页面URL - (NSString *)getCurrentURL { return [self stringByEvaluatingJavaScriptFromString:@"document.location.href"]; } /// 获取标题 - (NSString *)getTitle { return [self stringByEvaluatingJavaScriptFromString:@"document.title"]; } /// 获取所有图片链接 - (NSArray *)getImgs { NSMutableArray *arrImgURL = [[NSMutableArray alloc] init]; for (int i = 0; i < [self nodeCountOfTag:@"img"]; i++) { NSString *jsString = [NSString stringWithFormat:@"document.getElementsByTagName('img')[%d].src", i]; [arrImgURL addObject:[self stringByEvaluatingJavaScriptFromString:jsString]]; } return arrImgURL; } /// 获取当前页面所有点击链接 - (NSArray *)getOnClicks { NSMutableArray *arrOnClicks = [[NSMutableArray alloc] init]; for (int i = 0; i < [self nodeCountOfTag:@"a"]; i++) { NSString *jsString = [NSString stringWithFormat:@"document.getElementsByTagName('a')[%d].getAttribute('onclick')", i]; NSString *clickString = [self stringByEvaluatingJavaScriptFromString:jsString]; NSLog(@"%@", clickString); [arrOnClicks addObject:clickString]; } return arrOnClicks; } #pragma mark - #pragma mark 改变网页样式和行为 /// 改变背景颜色 - (void)setBackgroundColor:(UIColor *)color { NSString * jsString = [NSString stringWithFormat:@"document.body.style.backgroundColor = '%@'",[color webColorString]]; [self stringByEvaluatingJavaScriptFromString:jsString]; } /// 为所有图片添加点击事件(网页中有些图片添加无效,需要协议方法配合截取) - (void)addClickEventOnImg { for (int i = 0; i < [self nodeCountOfTag:@"img"]; i++) { //利用重定向获取img.src,为区分,给url添加'img:'前缀 NSString *jsString = [NSString stringWithFormat: @"document.getElementsByTagName('img')[%d].onclick = \ function() { document.location.href = 'img' + this.src; }",i]; [self stringByEvaluatingJavaScriptFromString:jsString]; } } /// 改变所有图像的宽度 - (void) setImgWidth:(int)size { for (int i = 0; i < [self nodeCountOfTag:@"img"]; i++) { NSString *jsString = [NSString stringWithFormat:@"document.getElementsByTagName('img')[%d].width = '%d'", i, size]; [self stringByEvaluatingJavaScriptFromString:jsString]; } } /// 改变所有图像的高度 - (void) setImgHeight:(int)size { for (int i = 0; i < [self nodeCountOfTag:@"img"]; i++) { NSString *jsString = [NSString stringWithFormat:@"document.getElementsByTagName('img')[%d].height = '%d'", i, size]; [self stringByEvaluatingJavaScriptFromString:jsString]; } } /// 改变指定标签的字体颜色 - (void)setFontColor:(UIColor *)color withTag:(NSString *)tagName { NSString *jsString = [NSString stringWithFormat: @"var nodes = document.getElementsByTagName('%@'); \ for(var i=0;i<nodes.length;i++){\ nodes[i].style.color = '%@';}", tagName, [color webColorString]]; [self stringByEvaluatingJavaScriptFromString:jsString]; } /// 改变指定标签的字体大小 - (void)setFontSize:(int)size withTag:(NSString *)tagName { NSString *jsString = [NSString stringWithFormat: @"var nodes = document.getElementsByTagName('%@'); \ for(var i=0;i<nodes.length;i++){\ nodes[i].style.fontSize = '%dpx';}", tagName, size]; [self stringByEvaluatingJavaScriptFromString:jsString]; } @end
原文出处:http://blog.csdn.net/duzixi/article/details/36047201