需求：每个tableviewcell 添加一个wkwebview 用于显示HTML 要求webview高度自适应，，每个cell高度自适应，，
网上查的资料，，使用的通知来刷新tableview，，会使tableview刷新次数过多，，本文的方法tableview只刷新一次
实现思路：cell中添加一个代理和一个index属性（cell协议方法中传入indexpath.row） 在webview加载完HTML协议方法中重新设置webview的高度 通过代理把每个cell的webview高度和这个cell的index传回Controller，在代理方法中把传回的index作为key，webview高度作为value存入一个字典，，当所有的cell里webview都加在完成，，此时Controller中已有一个保存了所有cell高度（即webview高度）的字典，，tableview设置高度的协议方法中通过indexpath.row 去字典中取cell的高度即可。。
怎样防止tableview刷新陷入死循环？通过存入本地一个状态，，具体看代码
为了方便在工程中添加名为test.text的文本文件，里面是一个数组，每个元素是字典存放HTML字符串
(
{
option = "<p style=\"line-height:20.1pt; margin:5pt 0pt\"><span style=\"font-family:'Times New Roman'; font-size:10.5pt\">A.</span><span style=\"font-family:'Times New Roman'; font-size:10.5pt\"> </span><span style=\"color:#333333; font-family:'Times New Roman'; font-size:10.5pt\">0.643(</span><span style=\"color:#333333; font-family:\U5b8b\U4f53; font-size:10.5pt\">\U7cbe\U786e\U5230\U767e\U5206\U4f4d</span><span style=\"color:#333333; font-family:'Times New Roman'; font-size:10.5pt\">)</span></p>";
},
{
option = "<p style=\"line-height:20.1pt; margin:5pt 0pt\"><span style=\"font-family:'Times New Roman'; font-size:10.5pt\">B.</span><span style=\"font-family:'Times New Roman'; font-size:10.5pt\"> </span><span style=\"color:#333333; font-family:'Times New Roman'; font-size:10.5pt\">0.64(</span><span style=\"color:#333333; font-family:\U5b8b\U4f53; font-size:10.5pt\">\U7cbe\U786e\U5230\U767e\U5206\U4f4d</span><span style=\"color:#333333; font-family:'Times New Roman'; font-size:10.5pt\">)</span></p>";
}
）
Controller.m中
@interface SecondViewController ()<UITableViewDelegate,UITableViewDataSource,webViewCellDelegate>
@property (nonatomic, strong) UITableView *tableview;
@property (nonatomic, strong) NSMutableDictionary *cellHDic;
@property (nonatomic, strong) NSMutableArray *dataArr;
@end
@implementation SecondViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
/// 存放所有cell里webview高度的字典
self.cellHDic = [NSMutableDictionary dictionary];
self.tableview = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height) style:UITableViewStylePlain];
[self.view addSubview:self.tableview];
self.tableview.delegate = self;
self.tableview.dataSource = self;
self.tableview.separatorStyle = UITableViewCellSeparatorStyleNone;
/// 防止tableview不停刷新的状态
[[NSUserDefaults standardUserDefaults] setObject:@"0" forKey:@"reload"];
[self loadData];
}
- (void)loadData{
[MBProgressHUD showHUDAddedTo:self.view animated:YES];
/// 从工程中取出数据
NSBundle *mainBundle = [NSBundle mainBundle];
NSString *txtPath = [mainBundle pathForResource:@"test" ofType:@"txt"];
NSArray *arr = [NSArray arrayWithContentsOfFile:txtPath];
self.dataArr = [NSMutableArray arrayWithArray:arr];
[self.tableview reloadData];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return self.dataArr.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSString *CellIdentifier = [NSString stringWithFormat:@"Cell%ld%ld", [indexPath section], [indexPath row]];
SecondTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (!cell) {
cell = [[SecondTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.backgroundColor = [UIColor whiteColor];
cell.delegate = self;
NSDictionary *dic = self.dataArr[indexPath.row];
[cell refreshWebView:dic[@"option"] indexPath:indexPath.row];
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return [self.cellHDic[[NSString stringWithFormat:@"%ld",indexPath.row]] floatValue];
}
- (void)webViewDidFinishLoad:(CGFloat)webHeight cellIndex:(NSInteger)index{
[self.cellHDic setValue:[NSString stringWithFormat:@"%f",webHeight] forKey:[NSString stringWithFormat:@"%ld",index]];
/// 防止一直刷新 只有字典中的元素个数和tableviewcell个数相同时才刷新tableview
if (self.cellHDic.count==self.dataArr.count) {
/// 通过NSUserDefaults 存的一个状态让tableview只刷新一次
if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"reload"] isEqualToString:@"0"]) {
NSArray *paths = [NSArray arrayWithObjects:[NSIndexPath indexPathForRow:index inSection:0],nil];
[self.tableview reloadRowsAtIndexPaths:paths withRowAnimation:UITableViewRowAnimationFade];
[MBProgressHUD hideHUDForView:self.view animated:YES];
[[NSUserDefaults standardUserDefaults] setObject:@"1" forKey:@"reload"];
}
}
}
SecondTableViewCell.h
@protocol webViewCellDelegate<NSObject>
/// 传回webview高度的代理
- (void)webViewDidFinishLoad:(CGFloat)webHeight cellIndex:(NSInteger)index;
@end
@interface SecondTableViewCell : UITableViewCell
@property (nonatomic,weak) id<webViewCellDelegate>delegate;
@property (nonatomic, assign) NSInteger indexPath;
- (void)refreshWebView:(NSString *)url indexPath:(NSInteger)index;
@end
- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
[self createView];
}
return self;
}
- (void)createView{
self.newsWebView = [[WKWebView alloc] init];
self.newsWebView.frame = CGRectMake(0, 0, self.contentView.frame.size.width, 0);
self.newsWebView.navigationDelegate = self;
self.newsWebView.scrollView.scrollEnabled = NO;
[self.newsWebView sizeToFit];
[self.contentView addSubview:self.newsWebView];
//
self.line = [[UIView alloc] init];
[self.contentView addSubview:self.line];
self.line.backgroundColor = [UIColor lightGrayColor];
}
- (void)refreshWebView:(NSString *)url indexPath:(NSInteger)index{
self.indexPath = index;
//// headerString 的添加是解决wkwebview 加载HTML是字体太小的问题
NSString *headerString = @"<header><meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=no'></header>";
[self.newsWebView loadHTMLString:[headerString stringByAppendingString:url] baseURL:nil];
}
- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation*)navigation{
}
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation*)navigation{
[webView evaluateJavaScript:@"document.body.scrollHeight"completionHandler:^(id _Nullable result,NSError * _Nullable error){
CGFloat height = [result floatValue];
self.newsWebView.frame = CGRectMake(0, 0, self.contentView.frame.size.width, height);
[self.delegate webViewDidFinishLoad:height cellIndex:self.indexPath];
self.line.frame = CGRectMake(0, height-0.5, self.contentView.frame.size.width, 0.5);
}];
}