小编JAA*_*JAA的帖子

我有NSUserDefaults保存的NSMutableArray.这个数组是我用户可以保存的"最喜欢的"项目,所以当我想添加一个项目时,我需要读取数组(来自NSuserDefault)并保存在第一个空闲位置.

我正在使用此方法在NSMutableArray中添加值

-(IBAction)save{
   NSMutableArray *abc = [[NSUserDefaults standardUserDefaults] objectForKey:@"12345"];
   int n = [abc count];
   [abc insertObject:@"aaa" atIndex:n];
   NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
   [[NSUserDefaults standardUserDefaults] setObject:abc forKey:@"12345"];
   [defaults synchronize];
   [abc release];
}

这是怎么回事？如果用户调用此方法两次,则第二次应用程序崩溃时会显示以下日志:

*由于未捕获的异常'NSInternalInconsistencyException'终止应用程序,原因:' - [__ NSCFArray insertObject:atIndex:]:发送到immutable对象的mutating方法'

为什么？为什么只是第二次？第一次工作正常!

我有一个NSString,我想知道它的高度来创建一个合适的UILabel.

这样做

NSString *string = @"this is an example"; 
CGSize size = [string sizeWithFont:[UIFont systemFontOfSize:10.0f] 
                          forWidth:353.0 
                     lineBreakMode:UILineBreakModeWordWrap];
float height = size.height;

身高现在是13.0.如果我使用这个字符串

NSString *string = @"this is an example this is an example this is an example 
                     this is an example this is an example this is an example 
                     this is an example this is an example this is an example 
                     this is an example this is an example this is an example 
                     this is an example this is an …

我正在使用TabBar应用程序.在一个视图中有一个UISearchBar,当按下时,键盘出现.

问题是键盘隐藏了标签栏.

你知道怎么解决吗？

我想做Twitter应用程序之类的东西:当有人写我时,我会收到推送通知; 如果我"滑动通知"应用程序启动,但不是在普通流中,它会在特定视图中以某人写信给我的推文开始!

在我的应用程序中,我有类似RSS阅读器的东西,当有新消息时推送通知到达.所以,我想打开"单一新闻视图",而不是主视图(现在正在发生).

我能做什么？

谢谢

我正在使用带有UITableViewCell的UITableView.我的应用程序支持横向,所以我创建了2个UITableViewCell:一个用于portraid,另一个用于横向.

在我的cellForRowAtIndexPath方法中,这是我的代码

static NSString *CellIdentifier;
static NSString *NibNamed;

UIDeviceOrientation deviceOrientation = [UIApplication sharedApplication].statusBarOrientation;

if (deviceOrientation != UIDeviceOrientationLandscapeLeft &&
    deviceOrientation != UIDeviceOrientationLandscapeRight)
{
    CellIdentifier= @"Cell1";
    NibNamed = @"cell_news";
}
else
{
    CellIdentifier= @"Cell2";
    NibNamed = @"cell_news_landscape";
}

[[NSBundle mainBundle] loadNibNamed:NibNamed owner:self options:NULL];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];


if (cell == nil)
{
    NSArray *nib = [[NSBundle mainBundle] loadNibNamed:NibNamed owner:self options:nil];
    cell = [nib objectAtIndex:0];
}
///here i add title, description, ecc... in my UITableViewCell

然后在shouldAutorotateToInterfaceOrientation我写了这个:

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
[my_table reloadData];
return …

我在UIScrollView中有一个UIImageView.我希望用户可以缩放和导航图像.

这是我的工作代码:

//img is the UIImageView
//scroller is the UIScrollView

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return img; 
}
- (void)viewDidLoad {
   [super viewDidLoad];
   UIImage *image = [UIImage imageNamed:@"map_screen.png"];
   img = [[UIImageView alloc] initWithImage:image];
   scroller.delegate = self;
   scroller.autoresizesSubviews = YES;
   scroller.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
   scroller.contentSize = img.frame.size;
   scroller.scrollEnabled = YES;
   scroller.directionalLockEnabled = NO;
   scroller.userInteractionEnabled = YES;

   CGSize ivsize = img.frame.size;
   CGSize ssize = scroller.frame.size;

   float scalex = ssize.width / ivsize.width;
   float scaley = ssize.height / ivsize.height;
   scroller.minimumZoomScale = fmin(1.0, fmax(scaley, …

我的UITableView需要在第一行中有一个图像.有什么问题？当用户向下滚动桌面视图时,他向上滚动,在图像上方有其他行的信息!你知道为什么吗？

这是我的代码(我使用的是UITableViewCell)

- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row != 0) {
    return 73.0;
}
else {
    return 109.0;
}   
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    if (indexPath.row == 0) {
        [[NSBundle mainBundle] loadNibNamed:@"customcell_3" owner:self options:NULL];
        cell = cellaNib_with_image;
    }
    else {
        [[NSBundle mainBundle] loadNibNamed:@"customcell_2" owner:self options:NULL];
        cell = cellaNib;
    }


}

if (indexPath.row == 0) {
    UIImage *rowBackground;
    UIImage *selectionBackground;
    rowBackground …

我的应用程序从互联网下载视频并将其保存在iPhone中.

我正在使用此代码

NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];

[request setHTTPMethod:@"GET"];
NSError *error;
NSURLResponse *response;


NSString *documentFolderPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *videosFolderPath = [documentFolderPath stringByAppendingPathComponent:@"videos"]; 

//Check if the videos folder already exists, if not, create it!!!
BOOL isDir;
if (([fileManager fileExistsAtPath:videosFolderPath isDirectory:&isDir] && isDir) == FALSE) {
    [[NSFileManager defaultManager] createDirectoryAtPath:videosFolderPath withIntermediateDirectories:YES attributes:nil error:nil];
}

NSString *filePath = [videosFolderPath stringByAppendingPathComponent:@"name.mp4"];

if ([fileManager fileExistsAtPath:filePath ] == YES) {
    NSLog (@"File exists");
}
else {
    NSLog (@"File not …