self.script = @"";
self.script = @"var xhr = new XMLHttpRequest();";
NSString* open = [NSString stringWithFormat:@"xhr.open('GET', '\%@', true);",[url absoluteString]];
self.script = [self.script stringByAppendingString:open];
self.script = [self.script stringByAppendingString:@"xhr.responseType = 'blob';"];
self.script = [self.script stringByAppendingString:@"window.webkit.messageHandlers.readBlob.postMessage('making sure script called');"];
self.script = [self.script stringByAppendingString:@"xhr.onload = function(e) { if (this.status == 200) { var blob = this.response; var reader = new window.FileReader(); reader.readAsBinaryString(blob); reader.onloadend = function() { window.webkit.messageHandlers.readBlob.postMessage(reader.result); }}};"];
self.script = [self.script stringByAppendingString:@"xhr.send();"];
reader.onloadend 这个方法不执行，有知道怎么回事的吗，请教大神门