我正在根据本教程(
http://bit.ly/NI9kQe)构建一个App,它使用自定义web api连接到Web服务器.其中一个要求是检测是否已点击“登录”或“注册”按钮.这是使用为接口构建器中的按钮设置的“标记”完成的(注册按钮的标记为1).
代码块位于btnLoginRegisterTapped方法内部,如下所示(错误发生在行 – > NSString * command =(sender.tag == 1)？@“register”：@“login”;)：
- (IBAction)btnLoginRegisterTapped:(id)sender {
//form fields validation
if (fldUserName.text.length < 4 || fldPassword.text.length < 4) {
// [UIAlertView error:@"Enter username and password over 4 chars each."];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Opps!!" message:@"Enter username and password over 4 chars each." delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
// optional - add more buttons:
[alert addButtonWithTitle:@"Yes"];
[alert show];
return;
}
//salt the password
NSString* saltedPassword = [NSString stringWithFormat:@"%@%@",fldPassword.text,kSalt];
//prepare the hashed storage
NSString* hashedPassword = nil;
unsigned char hashedPasswordData[CC_SHA1_DIGEST_LENGTH];
//hash the pass
NSData *data = [saltedPassword dataUsingEncoding: NSUTF8StringEncoding];
if (CC_SHA1([data bytes],[data length],hashedPasswordData)) {
hashedPassword = [[NSString alloc] initWithBytes:hashedPasswordData length:sizeof(hashedPasswordData) encoding:NSASCIIStringEncoding];
} else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Opps!!" message:@"Password cannot be reset!" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
// optional - add more buttons:
[alert addButtonWithTitle:@"Yes"];
[alert show];
return;
}
//************ THIS IS WHERE THE ERROR OCCURS *****************//
//check whether it's a login or register
NSString* command = (sender.tag==1)?@"register":@"login";
NSMutableDictionary* params =[NSMutableDictionary dictionaryWithObjectsAndKeys:
command,@"command",fldUserName.text,@"username",hashedPassword,@"password",nil];
//make the call to the web API
[[API sharedInstance] commandWithParams:params
onCompletion:^(NSDictionary *json) {
//handle the response
//result returned
NSDictionary* res = [[json objectForKey:@"result"] objectAtIndex:0];
if ([json objectForKey:@"error"]==nil && [[res objectForKey:@"IdUser"] intValue]>0) {
//success
[[API sharedInstance] setUser: res];
[self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
//show message to the user
[[[UIAlertView alloc] initWithTitle:@"Logged in"
message:[NSString stringWithFormat:@"Welcome %@",[res objectForKey:@"username"] ]
delegate:nil
cancelButtonTitle:@"Close"
otherButtonTitles: nil] show];
} else {
//error
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Opps!!" message:@"Server down? Try Again" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
// optional - add more buttons:
[alert addButtonWithTitle:@"Yes"];
[alert show];
return;
}
}];
}
当我尝试构建项目(实际工作空间)时,我收到错误：
在’_strong id’类型的对象上找不到属性’tag’
我正在使用xcode 5.0部署iOS7.
谢谢,
