在我正在开发的应用程序中,我有一个视图,当用户将文档导入应用程序时,该视图首先出现。我想要的是出现一个对话框(可能是UIAlert 或活动表菜单),询问用户是否真的要导入该文件(是或取消)。我想知道如何在执行导入操作之前使 UIAlert/Actionsheet 菜单出现,以及如何在用户单击“是”或“否”或“更改文件”时分配要完成的操作
出现的视图称为 ProgressBarView.m/h。其中是这样的viewdidload:
- (void)viewDidLoad
{
[super viewDidLoad];
self.progressBar.progressTintColor = [UIColor colorWithRed:153.0/255 green:0 blue:0 alpha:1.0];
self.progressBar.progress = 0.0;
/*progressValueLabel = [NSString stringWithFormat:@"%.0f%%", (self.progressBar.progress * 100)];*/
self.progressTimer = [NSTimer scheduledTimerWithTimeInterval:0.3f
target:self
selector:@selector(changeProgressValue)
userInfo:nil
repeats:YES];
}
然后在 appdidFinishLaunchwith 选项中开始导入时在应用程序委托中调用它:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
NSURL *url = (NSURL *)[launchOptions valueForKey:UIApplicationLaunchOptionsURLKey];
if (url != nil && [url isFileURL]) {
**[self handleImportURL:url];** // this is the function that handles the import
}
导入并调用progressView的函数如下:
- (void)handleImportURL:(NSURL *)url
{
// Show progress window
UIStoryboard * storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
__block PVProgressViewController * progressController = [storyboard instantiateViewControllerWithIdentifier:@"kProgressViewController"];
self.window.rootViewController = progressController;
// Perform import operation
dispatch_async(dispatch_get_global_queue(0, 0), ^{
NSError *outError;
NSString * csvString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&outError];
NSArray * array = [csvString csvRows];
[[PVDatabaseController sharedController] importArray:array progressHandler:^(float progress) {
progressController.progressBar.progress = progress;
}];
dispatch_async(dispatch_get_main_queue(), ^{
self.window.rootViewController = controller;
});
});
}