使用 UIWebView 调用 Javascript
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Calling Javascript using UIWebView
提问by learner2010
I am trying to call a javascript in a html page using the function -
我正在尝试使用该函数在 html 页面中调用 javascript -
View did load function
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writablePath = [documentsDirectory stringByAppendingPathComponent:@"BasicGraph.html"];
NSURL *urlStr = [NSURL fileURLWithPath:writablePath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *myPathInfo = [[NSBundle mainBundle] pathForResource:@"BasicGraph" ofType:@"html"];
[fileManager copyItemAtPath:myPathInfo toPath:writablePath error:NULL];
[graphView loadRequest:[NSURLRequest requestWithURL:urlStr]];
}
- (void) webViewDidFinishLoad:(UIWebView *)webView
{
[graphView stringByEvaluatingJavaScriptFromString:@"methodName()"];
}
Here is the javascript on the html page -
这是 html 页面上的 javascript -
<script>
function methodName()
{
// code to draw graph
}
However, the function methodName()is not getting called but after window.onload = function () everything is working fine..
但是，该函数methodName()没有被调用，但在 window.onload = function () 之后一切正常..
I am trying to integrate RGraphsinto my application and Basic.htmlis the html page in which the javascripts are written.
我正在尝试将RGraphs集成到我的应用程序中，并且Basic.html是编写 javascripts 的 html 页面。
It would be great if someone could help me out with this.
如果有人能帮我解决这个问题，那就太好了。
回答by Bj?rn Kaiser
Simple: You try to execute the JS function from Objective-C before the page even has been loaded.
很简单：您尝试在页面加载之前从 Objective-C 执行 JS 函数。
Implement the UIWebView's delegate methodwebViewDidFinishLoad:in your UIViewController and in there you call [graphView stringByEvaluatingJavaScriptFromString:@"methodName()"];to make sure the function gets called afterthe page has been loaded.
在 UIViewController 中实现UIWebView 的委托方法webViewDidFinishLoad:，并在那里调用[graphView stringByEvaluatingJavaScriptFromString:@"methodName()"];以确保在页面加载后调用该函数。
回答by Kalel Wade
To clarify a little bit more.
为了澄清一点。
.h - implement the UIWebViewDelegate
.h - 实现 UIWebViewDelegate
@interface YourViewController : UIViewController <UIWebViewDelegate>
@property (weak, nonatomic) IBOutlet UIWebView *webView;
@end
.m
.m
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *path = @"http://www.google.com";
[_webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:path]]];
_webView.delegate = self; //Set the webviews delegate to this
}
- (void) webViewDidFinishLoad:(UIWebView *)webView
{
//Execute javascript method or pure javascript if needed
[_webView stringByEvaluatingJavaScriptFromString:@"methodName();"];
}
You could also assign the delegate from storyboard instead of doing it in the code.
您还可以从故事板分配委托，而不是在代码中进行。
