UIImagePickerController在IOS6.0上的Bug

UIImagePickerController在iOS6.0 的iPad上，不能只用在橫向的設計上，會導致Crash，其原因可以看
https://devforums.apple.com/message/731764#731764

裡面有詳細的說明，這的錯誤點是iOS6.0 SDK的原生錯誤，而此錯誤只會出現在不要旋轉模式的橫向App。以下是解決方法。

1. 沿用前一篇UIImagePickerController的例子，將方向設成橫向

2. 加入新的class檔，這是為了要避開原生的UIImagePickerController錯誤。

3. noRotationImagePicker.m上加入避開錯誤的程式碼

#import "noRotationImagePicker.h"

@interface noRotationImagePicker ()

@end

@implementation noRotationImagePicker

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (BOOL)shouldAutorotate
{
    return NO;
}

-(UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
    return UIInterfaceOrientationPortrait;
}

4. 在mainViewController.m上使用的地方，改成呼叫自己所改的Class

- (IBAction)openPhotoLibrary:(id)sender {
  
    //UIView *anchor = sender;
       
    UIImagePickerController *m_imagePicker = [[noRotationImagePicker alloc] init];
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypePhotoLibrary]) {
      
        m_imagePicker.wantsFullScreenLayout = YES;
        m_imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        m_imagePicker.delegate = self;
        [m_imagePicker setAllowsEditing:YES]; // 圖片出現可編輯的選項
      
        popover = [[UIPopoverController alloc] initWithContentViewController:m_imagePicker];
      
        [popover setPopoverContentSize:CGSizeMake(300, 300)];
               
        [popover presentPopoverFromRect:CGRectMake(0,0,300,300) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; // 此處popover的位置改成自定       
      
    }

}
- (IBAction)openPhotoAlbum:(id)sender {
  
    UIView *anchor = sender;
    UIImagePickerController *m_imagePicker = [[noRotationImagePicker alloc] init];
    if ([UIImagePickerController isSourceTypeAvailable:
         UIImagePickerControllerSourceTypeSavedPhotosAlbum]) {
      
      
        m_imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
        m_imagePicker.delegate = self;
        [m_imagePicker setAllowsEditing:YES];
      
        popover = [[UIPopoverController alloc] initWithContentViewController:m_imagePicker];
      
        [popover setPopoverContentSize:CGSizeMake(300, 300)];
      
        [popover presentPopoverFromRect:anchor.frame inView:anchor.superview permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
      
    }
}

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
    [imageView setImage:image];
   
     [popover dismissPopoverAnimated:YES]; // 使用正確的popover dismiss
   
}

UIImagePickerController的使用（三）

延續前一篇，當我取得了一個圖檔之後，除了顯示出來，也希望可以儲存起來，以下就加入儲存與讀取的機制。儲存位置在App的Document區。

1. 在Storyboard加上三個Button

2. 在mainViewController.m加上所需程式碼
- (IBAction)saveScreen:(id)sender {
   
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage.png"];
   
    NSData *imageData = UIImagePNGRepresentation(imageView.image);
   
    [imageData writeToFile:savedImagePath atomically:YES];   
}


- (IBAction)clearScreen:(id)sender {
    [imageView setImage:nil];
}

- (IBAction)readPNG:(id)sender {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    //NSString *ImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage.png"];
   
    NSURL *recordedFile = [NSURL fileURLWithPath:[documentsDirectory stringByAppendingString:@"/savedImage.png"]];
   
    UIImage *image1 =  [UIImage imageWithData:[NSData dataWithContentsOfURL:recordedFile]];
    imageView.image = image1;
   
}

UIToolBar的基本使用(四）

延續前一篇的實驗，使Toolbar及BarItem的字體放大

實作如下

1. 只要在dynamicToolBarViewController.m上修改程式碼即可
-(void)setupMyToolBar
{
    myToolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 682, 1024, 66)];
   
    myToolBar.barStyle = UIBarStyleBlackTranslucent;

    UIFont *font = [UIFont boldSystemFontOfSize:32];//改變字體大小
    NSDictionary *attribute = [NSDictionary dictionaryWithObject:font forKey:UITextAttributeFont];
   
   
    //myBarItem1= [[UIBarButtonItem alloc] initWithCustomView:label];
    myBarItem1= [[UIBarButtonItem alloc]initWithTitle:@"Test1" style:UIBarButtonItemStylePlain target:self action:@selector(showText1)];
   
    myBarItem2= [[UIBarButtonItem alloc]initWithBarButtonSystemItem:(UIBarButtonSystemItemFixedSpace) target:nil action:nil];
   
   
    myBarItem3= [[UIBarButtonItem alloc]initWithTitle:@"Test2" style:UIBarButtonItemStyleBordered target:self action:@selector(showText2)];
   
    myBarItem4= [[UIBarButtonItem alloc]initWithBarButtonSystemItem:(UIBarButtonSystemItemFlexibleSpace) target:nil action:nil];
   
    myBarItem5= [[UIBarButtonItem alloc]initWithTitle:@"Test3" style:UIBarButtonItemStyleDone target:self action:@selector(showText3)];
   
    myBarItem2.width = 360;
   
    [myBarItem1 setTitleTextAttributes:attribute forState:UIControlStateNormal];
   
    [myBarItem3 setTitleTextAttributes:attribute forState:UIControlStateNormal];
   
    [myBarItem5 setTitleTextAttributes:attribute forState:UIControlStateNormal];
   
    NSArray *toolbarItems = [[NSArray alloc] initWithObjects:myBarItem1,myBarItem2,myBarItem3,myBarItem4,myBarItem5,nil];
    myToolBar.items = toolbarItems;
   
}


2. 顯示效果

UIAlertView的基本使用(六)

有時我們需要在alterView上放置圖片，來清楚地標示些資訊，以下是實作方式

根據前一篇的例子，加上兩張圖片來做顯示


很簡當，只需在alter上加入UIImageView就可以了

- (void) alertViewAction1
{
  
    UIAlertView *alert1 = [[UIAlertView alloc] initWithTitle:@"Title" message:@"Message 1......\nMessage 2......" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:@"Button 1", @"Button 2", @"Button 3", nil];
  
  
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(180, 10, 100, 100)];
  
    NSString *path = [[NSString alloc] initWithString:[[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"1001.png"]];
    UIImage *bkgImg = [[UIImage alloc] initWithContentsOfFile:path];
    [imageView setImage:bkgImg];
  
    [alert1 addSubview:imageView];
  
  
    UIImageView *imageView2 = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 100, 100)];
  
    NSString *path2 = [[NSString alloc] initWithString:[[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"1002.png"]];
    UIImage *bkgImg2 = [[UIImage alloc] initWithContentsOfFile:path2];
    [imageView2 setImage:bkgImg2];
  
    [alert1 addSubview:imageView2];
  
  
    [alert1 show];
  
}

UINavigationBar的基本使用(二)

延續前一篇 UINavigationBar的基本使用(一) 的專案，加上一個動態popover的使用，主要語法如下

[popover presentPopoverFromRect:CGRectMake(0, 0, 2000, 50) inView:super.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES]; 

presentPopoverFromRect：設定popover在iPAD上起始的位置點


1. 在dynamicNavBarViewController. m加入所需程式碼

-(void)myNavAction1
{
    NSString *text = @"測試左鍵";
   
    showLabel.text = text;
   
   
    [self popoverAction1];
}

-(void)myNavAction2
{
    NSString *text = @"測試右鍵";
   
    showLabel.text = text;
   
    [self popoverAction2];
   
}

-(void)myNavAction3
{
    NSString *text = @"測試右二鍵";
   
    showLabel.text = text;
   
    [self popoverAction3];
}

- (void) popoverAction1 {
   
    SecondView *showView1 = [[SecondView alloc] init];
   
    showView1.view.backgroundColor = [UIColor redColor];
   
   
    UILabel *testLabel =[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 150, 150)];
    testLabel.backgroundColor = [UIColor clearColor];
    testLabel.textColor = [UIColor blackColor];
    testLabel.text = @"左鍵測試";
   
    [showView1.view addSubview:testLabel ];
   
    testLabel.Font = [UIFont boldSystemFontOfSize:25];
   
    popover = [[UIPopoverController alloc]
               initWithContentViewController:showView1];
   
    [popover setPopoverContentSize:CGSizeMake(300, 300)];
   
    [popover presentPopoverFromRect:CGRectMake(0, 0, 50, 50) inView:super.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
}



- (void) popoverAction2 {
   
    SecondView *showView1 = [[SecondView alloc] init];
   
    showView1.view.backgroundColor = [UIColor redColor];
   
   
    UILabel *testLabel =[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 150, 150)];
    testLabel.backgroundColor = [UIColor clearColor];
    testLabel.textColor = [UIColor blackColor];
    testLabel.text = @"右鍵測試";
   
    testLabel.Font = [UIFont boldSystemFontOfSize:25];
   
    [showView1.view addSubview:testLabel ];
   
   
    popover = [[UIPopoverController alloc]
               initWithContentViewController:showView1];
   
    [popover setPopoverContentSize:CGSizeMake(300, 300)];
   
    [popover presentPopoverFromRect:CGRectMake(0, 0, 2000, 50) inView:super.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
}


- (void) popoverAction3 {
   
    SecondView *showView1 = [[SecondView alloc] init];
   
    showView1.view.backgroundColor = [UIColor redColor];
   
   
    UILabel *testLabel =[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 150, 150)];
    testLabel.backgroundColor = [UIColor clearColor];
    testLabel.textColor = [UIColor blackColor];
   
    testLabel.Font = [UIFont boldSystemFontOfSize:25];
   
    testLabel.text = @"右二鍵測試";
   
    [showView1.view addSubview:testLabel ];
   
   
    popover = [[UIPopoverController alloc]
               initWithContentViewController:showView1];
   
    [popover setPopoverContentSize:CGSizeMake(300, 300)];
   
    [popover presentPopoverFromRect:CGRectMake(0, 0, 1850, 50) inView:super.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
}

2. 顯示結果

xcode 的Quick Help

在寫App時經常會卡在一些小細節，Xcode提供了很好的協助機制，就是Quick Help。

1. 例如如果臨時遇到 popover的問題如圖，只要用鼠標將特殊字標起來變成藍色，右邊的Quick Help，就會出現相關的說明資料。

2. 如果還是不清楚，就在Quick Help向下滑動，最下面通常會有範例，如圖，可以看到popovers的例子。

3. 點擊popovers，會出現例子的說明資料，除了Next可以仔細地瀏覽細節外，最重要的是在Open Project，點擊後，會直接在Xcode上開啓這個例子。

4. 開啓例子後，直接就可以執行及追蹤程式碼。這樣就可以很快地瞭解該功能的使用了。

Navigation Controller實作(二）

延續前一篇 Navigation Controller實作(一）

要在Navigation Bar上加入title的顯示

修改如下

1.在AppViewController.m加上顯示程式碼

 - (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
  
    [self setTitle:@"Main Page"];
  
}

- (IBAction)toPage2:(id)sender {
    SecondViewController *svc = [self.storyboard instantiateViewControllerWithIdentifier:@"SecondId"];

    [svc setValue:@"Page2" forKey:@"transferString"];
   
    [self.navigationController pushViewController:svc animated:YES];
}

2. 在SecondViewController.h加上傳送用的字串變數。
#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController
{
    NSString *transferString;
}

@end


3. 在SecondViewController.m加上顯示title的程式碼
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
   
    self.title=transferString;
   
}


4. 顯示結果