Question

我尝试使用给定内容计算UIWebView的大小，但不显示视图。我只需要知道尺寸。

我的问题：当我执行代码时，不会调用UIWebView的委托。为什么呢？

MessageSizeCaluclator.h

#import < Foundation/Foundation.h>

@class Message;

@interface MessageSizeCaluclator : NSObject <UIWebViewDelegate>

- (id)initWithMessage:(Message*)message;
- (void)saveSize;

@end

MessageSizeCaluclator.m

#import "Message.h"
#import "MessageSizeCaluclator.h"


@interface MessageSizeCaluclator () <UIWebViewDelegate>

@property (strong, nonatomic) Message* message;
@property (strong, nonatomic) UIWebView* webView;

@end


@implementation MessageSizeCaluclator

@synthesize message = _message;
@synthesize webView = _webView;


- (id)initWithMessage:(Message*)message
{
self = [super init];

if (self) {
    _message = message;

    // WebView
    _webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 10, 10)];
    _webView.delegate = self;
}

return self;
}

- (void)saveSize
{
NSLog(@"%s message = %@", __PRETTY_FUNCTION__, _message.text);

[_webView loadHTMLString:[NSString stringWithFormat:@"<div style='font-family:Helvetica;font-size:13px;'>This is a test</div>", _message.text]
                                 baseURL:nil];
}

#pragma mark - Web view delegate

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
NSLog(@"%s", __PRETTY_FUNCTION__);
}

- (void)webViewDidStartLoad:(UIWebView *)webView
{
NSLog(@"%s", __PRETTY_FUNCTION__);
}

- (void)webViewDidFinishLoad:(UIWebView *)webView
{
NSLog(@"%s", __PRETTY_FUNCTION__);
}

@end

实施

    MessageSizeCaluclator* messageSizeCalculator = [[MessageSizeCaluclator alloc] initWithMessage:message];
    [messageSizeCalculator saveSize];

Answer 1

将UIWebView添加到某些UIView，使其框架在屏幕外（因此用户无法看到它）。如果UIWebView不在应用程序的视图层次结构中，则从不调用委托方法。

UIWebView：不会调用Delegate

1 个答案: