当我尝试更改UITextView
文字时,我的应用程序崩溃了。
以下是代码:(头文件):
//
#import <UIKit/UIKit.h>
@interface DetailViewController : UIViewController {
IBOutlet UIImageView *appImage;
IBOutlet UILabel *appName;
IBOutlet UILabel *appDeveloper;
IBOutlet UILabel *appVersion;
UIActivityIndicatorView *loading;
IBOutlet UITextView *appAbout;
NSString *selectedApp;
}
@property (nonatomic, retain) NSString *selectedApp;
@property (nonatomic, retain) IBOutlet UIImageView *appImage;
@property (nonatomic, retain) IBOutlet UILabel *appName;
@property (nonatomic, retain) IBOutlet UILabel *appDeveloper;
@property (nonatomic, retain) IBOutlet UILabel *appVersion;
@property (nonatomic, retain) UIActivityIndicatorView *loading;
@property (nonatomic, retain) UITextView *appAbout;
@end
实施档案:
- (void)loadData {
NSString *trimmedString = [selectedApp stringByReplacingOccurrencesOfString:@" " withString:@"%20"];
self.navigationItem.title = @"Info";
NSLog(@"%@", trimmedString);
NSString *website = [NSString stringWithFormat:@"http://shaymargolisapps.x10.mx/send.php?mission=GetNameOfApps&aname=%@", trimmedString];
NSData *dataURL = [NSData dataWithContentsOfURL:[NSURL URLWithString:website]];
NSString *strResult = [[[NSString alloc] initWithData:dataURL encoding:NSUTF8StringEncoding]autorelease];
appName.text = strResult;
NSString *website1 = [NSString stringWithFormat:@"http://shaymargolisapps.x10.mx/send.php?mission=GetDeveloperOfApp&aname=%@", trimmedString];
NSData *dataURL1 = [NSData dataWithContentsOfURL:[NSURL URLWithString:website1]];
NSString *strResult1 = [[[NSString alloc] initWithData:dataURL1 encoding:NSUTF8StringEncoding]autorelease];
appDeveloper.text = strResult1;
NSString *website2 = [NSString stringWithFormat:@"http://shaymargolisapps.x10.mx/send.php?mission=GetVersionOfApp&aname=%@", trimmedString];
NSData *dataURL2 = [NSData dataWithContentsOfURL:[NSURL URLWithString:website2]];
NSString *strResult2 = [[[NSString alloc] initWithData:dataURL2 encoding:NSUTF8StringEncoding]autorelease];
appVersion.text = strResult2;
NSString *website3 = [NSString stringWithFormat:@"http://shaymargolisapps.x10.mx/send.php?mission=GetInfoOfApp&aname=%@", trimmedString];
NSData *dataURL3 = [NSData dataWithContentsOfURL:[NSURL URLWithString:website3]];
NSString *strResult3 = [[[NSString alloc] initWithData:dataURL3 encoding:NSUTF8StringEncoding]autorelease];
NSLog(@"%@", strResult3);
**appAbout.text = strResult3;**
NSString *website4 = [NSString stringWithFormat:@"http://shaymargolisapps.x10.mx/send.php?mission=GetImageOfApp&aname=%@", trimmedString];
NSData *dataURL4 = [NSData dataWithContentsOfURL:[NSURL URLWithString:website4]];
NSString *strResult4 = [[[NSString alloc] initWithData:dataURL4 encoding:NSUTF8StringEncoding]autorelease];
NSData* imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:strResult4]];
UIImage* image = [[UIImage alloc] initWithData:imageData];
[appImage setImage:image];
[image release];
[imageData release];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[loading stopAnimating];
[loading setHidden:YES];
[appName setHidden:NO];
[appDeveloper setHidden:NO];
[appVersion setHidden:NO];
[appImage setHidden:NO];
[appAbout setHidden:NO];
}
我的应用程序在appAbout.text = strResult3;
行崩溃了。我做错了什么?
使用[self performSelectorInBackground:@selector(loadData) withObject:nil];
viewDidLoad
调用loadData
(Xcode 4.4 DP2,iPhone模拟器5.1,基本SDK 4.3)
答案 0 :(得分:4)
您不得从后台线程更改UI *对象。这必须从主线程完成。
您可以使用gcd在主线程上执行更改。像这样:
/* ... */
NSString *strResult4 = [[[NSString alloc] initWithData:dataURL4 encoding:NSUTF8StringEncoding]autorelease];
NSData* imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:strResult4]];
UIImage* image = [[UIImage alloc] initWithData:imageData];
dispatch_async(dispatch_get_main_queue(), ^{
self.navigationItem.title = @"Info";
appName.text = strResult;
appDeveloper.text = strResult1;
appVersion.text = strResult2;
appAbout.text = strResult3;
[appImage setImage:image];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[loading stopAnimating];
[loading setHidden:YES];
[appName setHidden:NO];
[appDeveloper setHidden:NO];
[appVersion setHidden:NO];
[appImage setHidden:NO];
[appAbout setHidden:NO];
});
[image release];
[imageData release];