Question

我正在开发一个非常简单的iOS应用程序，让我开始编程。它是一个基于选项卡的应用程序，因此有一个MainWindow.xib以及FirstView.xib和SecondView.xib。所有这一切都发生在第一个视图中。我想在第一个视图中添加一个进度条，当我添加对象时，它将自己附加到FirstView.xib并显示并让我移动它。要进行测试，alpha设置为1.00，进度设置为0.5。无论如何，无论我做什么，它都不会出现。我做错了什么？

AppDelegate.m：

@synthesize window=_window;

@synthesize tabBarController=_tabBarController;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Add the tab bar controller's current view as a subview of the window
    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application
{
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
}

- (void)applicationWillTerminate:(UIApplication *)application
{
}

- (void)dealloc
{
    [_window release];
    [_tabBarController release];
    [super dealloc];
}
@end

FirstViewController.h：

#import <UIKit/UIKit.h>
NSTimer *stopWatchTimer;
NSDate *startDate;

@interface FirstViewController : UIViewController {

    UILabel *label;
    UILabel *stopWatchLabel;
    UIProgressView *progressBar;
    UIButton *topButton;
}
@property (nonatomic, retain) IBOutlet UILabel *stopWatchLabel;
@property (nonatomic, retain) IBOutlet UIProgressView *progressBar;
- (IBAction)onStartPressed:(id)sender;
- (IBAction)onStopPressed:(id)sender;
- (IBAction)onResetPressed:(id)sender;

@end

FirstViewController.m

#import "FirstViewController.h"


@implementation FirstViewController
@synthesize progressBar;
@synthesize stopWatchLabel;


/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.*/
- (void)viewDidLoad
{
    [super viewDidLoad];
}


- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}


- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc. that aren't in use.
}


- (void)viewDidUnload
{
    [self setStopWatchLabel:nil];
    [topButton release];
    topButton = nil;
    [super viewDidUnload];

    // Release any[progress release];
    progressBar = nil;
    [progressBar release];
    progressBar = nil;
    [self setProgressBar:nil];
    //retained subviews of the[self setProgressBar:nil];

    // e.g. self.myOutlet = nil;
}

static NSInteger counter=0;
static NSInteger secs=0;
static NSInteger mins=0;
static NSInteger hrs=0;

- (void)dealloc
{
    [stopWatchLabel release];
    [label release];

    [topButton release];
    [super dealloc];
}

-(void)updateTimer {
//updates the timer    }

    -(void)clearTimer {
//clears the timer        


}

-(void)stopTimer{
//stops the timer    }


- (IBAction)onStartPressed:(id)sender {
    //stopWatchLabel.text=@"Start Pressed";
    progressBar.alpha=1.0;
//run timer    }


- (IBAction)onStopPressed:(id)sender {
    [self stopTimer];
}

- (IBAction)onResetPressed:(id)sender {
    [self stopTimer];
    [self clearTimer];
}
@end

Answer 1

创建视图后，您需要做两件事：您必须将其添加为可见视图的子视图并设置适当的框架。

以下是如何做到这一点：

 [self.view addSubview:progressBar];
progressBar.frame = CGRectMake(x, y, width, height);

编辑：可能与您的问题完全无关，但这都是错误的：

- (void)viewDidUnload
{
    [self setStopWatchLabel:nil];
    [topButton release];
    topButton = nil;
    [super viewDidUnload];

    // Release any[progress release];
    progressBar = nil;
    [progressBar release];
    progressBar = nil;
    [self setProgressBar:nil];
    //retained subviews of the[self setProgressBar:nil];

    // e.g. self.myOutlet = nil;
}

您可能希望它看起来像以下内容：

- (void)viewDidUnload
{
    [super viewDidUnload];
    [self setStopWatchLabel:nil];
    [topButton release];
    topButton = nil;
    [label release];
    label = nil;
    self.progressBar = nil;
}

确保你明白你做错了什么。这一点非常重要，否则您的应用程序将泄漏和/或崩溃。

你的其余代码并没有真正做任何事情。你似乎在做IB中的所有事情，所以我想这就是你的问题所在。

使进度视图可见

1 个答案: