文本视图(UITextView)

    

开篇小技巧

视图类

- (void)viewDidLoad {
  [super
viewDidLoad];

  self.title =
@"主屏幕";
  if ( !items_ ) {

//将类的名字放进数组
    items_ = [[NSArray
alloc] initWithObjects:
                                @"UIKitPrjTextView",
                                @"UIKitPrjEditableTextView",
                                @"UIKitPrjWorkingWithTheSelection",
                                nil ];
  } 
}

- (void)viewWillAppear:(BOOL)animated {
  [super
viewWillAppear:animated];

  [self.navigationController
setNavigationBarHidden:NO
animated:NO];
  [self.navigationController
setToolbarHidden:NO
animated:NO];

  // 还原颜色
  [UIApplication
sharedApplication].statusBarStyle =
UIStatusBarStyleDefault;
  self.navigationController.navigationBar.barStyle
= UIBarStyleDefault;
  self.navigationController.navigationBar.translucent
= NO;
  self.navigationController.toolbar.barStyle
= UIBarStyleDefault;
  self.navigationController.toolbar.translucent
= NO;

  [UIView
setAnimationsEnabled:YES];
}

#pragma mark UITableView methods

- (NSInteger)tableView:(UITableView*)tableView numberOfRowsInSection:(NSInteger)section
{
  return [items_
count];
}

- (UITableViewCell*)tableView:(UITableView*)tableView  cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
  static
NSString *CellIdentifier =
@"Cell";
  
  UITableViewCell *cell = [tableView
dequeueReusableCellWithIdentifier:CellIdentifier];
  if (cell ==
nil) {
    cell = [[[UITableViewCell
alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier]
autorelease];
  }
  
  NSString* title = [items_
objectAtIndex:indexPath.row];
  cell.textLabel.text = [title
stringByReplacingOccurrencesOfString:@"UIKitPrj"
withString:@""];

  return cell;
}

- (void)tableView:(UITableView*)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath
{
//从数组中将类的名取出, 用NSClassFromString( className )真正转化成实体类
  NSString* className = [items_
objectAtIndex:indexPath.row];
  Class class =
NSClassFromString( className );
 
UIViewController* viewController = [[[class
alloc] init]
autorelease];
  if ( !viewController ) {
    NSLog(
@"%@ 没有数据.", className );
    return;
  } 
  [self.navigationController
pushViewController:viewController
animated:YES];
}

UITextView* textView = [[[UITextView
alloc] init]
autorelease];
  textView.frame =
self.view.bounds;
  textView.autoresizingMask =
    UIViewAutoresizingFlexibleWidth |
UIViewAutoresizingFlexibleHeight;
  //textView.editable = NO; //<
不可编辑

  textView.backgroundColor = [UIColor
blackColor]; //<
背景为黑色
  textView.textColor = [UIColor
whiteColor]; //<
字符为白色
  textView.font = [UIFont
systemFontOfSize:32];
//< 字体的设置
  textView.text =
@"学习UITextView!\n"
                   "第2行\n"
                   "第3行\n"
                   "4行\n"
                   "第5行\n"
                   "第6行\n"
                   "第7行\n"
                   "第8行\n"
                   "第9行\n"
                   "第10行\n"
                   "第11行\n"
                   "第12行\n";

  [self.view
addSubview:textView];

- (void)dealloc {
  [textView_
release];  
  [super
dealloc];
}

- (void)viewDidLoad {
  [super
viewDidLoad];

  textView_ = [[UITextView
alloc] init];
  textView_.frame =
self.view.bounds;
  textView_.autoresizingMask =
UIViewAutoresizingFlexibleWidth |
                               UIViewAutoresizingFlexibleHeight;
  textView_.delegate =
self;
  textView_.text =
@"亲们，可以编辑这一段文本。";

  [self.view
addSubview:textView_];
}

- (void)viewWillAppear:(BOOL)animated {
  [super
viewWillAppear:animated];
  [self.navigationController
setNavigationBarHidden:NO
animated:YES];
  [self.navigationController
setToolbarHidden:NO
animated:YES];
}

- (void)viewDidAppear:(BOOL)animated {
  [super
viewDidAppear:animated];
  [self
textViewDidEndEditing:textView_];
//< 画面显示时设置为非编辑模式
}

- (void)viewWillDisappear:(BOOL)animated {
  [super
viewWillDisappear:animated];
  [textView_
resignFirstResponder]; //<
画面跳转时设置为非编辑模式
}

- (void)textViewDidBeginEditing:(UITextView*)textView {
  static
const CGFloat kKeyboardHeight =
216.0;

  // 按钮设置为［完成］
  self.navigationItem.rightBarButtonItem =
    [[[UIBarButtonItem
alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone
                                                  
target:self
                                                  
action:@selector(doneDidPush)]
autorelease];
  [UIView
beginAnimations:nil
context:nil];
  [UIView
setAnimationDuration:0.3];
  // 缩小UITextView以免被键盘挡住
  CGRect textViewFrame = textView.frame;
  textViewFrame.size.height =
self.view.bounds.size.height
- kKeyboardHeight;
  textView.frame = textViewFrame;
  // 工具条位置上移
  CGRect toolbarFrame =
self.navigationController.toolbar.frame;
  toolbarFrame.origin.y =
    self.view.window.bounds.size.height
- toolbarFrame.size.height - kKeyboardHeight;
  self.navigationController.toolbar.frame
= toolbarFrame;
  [UIView
commitAnimations];
}

- (void)textViewDidEndEditing:(UITextView*)textView {
  // 按钮设置为[编辑]
  self.navigationItem.rightBarButtonItem =
    [[[UIBarButtonItem
alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit
                                                  
target:self
                                                  
action:@selector(editDidPush)]
autorelease];
  [UIView
beginAnimations:nil
context:nil];
  [UIView
setAnimationDuration:0.3];
  // 恢复UITextView的尺寸
  textView.frame =
self.view.bounds;
  // 恢复工具条的位置
  CGRect toolbarFrame =
self.navigationController.toolbar.frame;
  toolbarFrame.origin.y =
    self.view.window.bounds.size.height
- toolbarFrame.size.height;
  self.navigationController.toolbar.frame
= toolbarFrame;
  [UIView
commitAnimations];
}

- (void)editDidPush {
  [textView_
becomeFirstResponder];
}

- (void)doneDidPush {
  [textView_
resignFirstResponder];
}

#import "UIKitPrjWorkingWithTheSelection.h"

static const
CGFloat kKeyboardHeight =
216.0;

@implementation UIKitPrjWorkingWithTheSelection

- (void)dealloc {
  [textView_
release];  
  [super
dealloc];
}

- (void)viewDidLoad {
  [super
viewDidLoad];

  // UITextView的追加
  textView_ = [[UITextView
alloc] init];
  textView_.frame =
self.view.bounds;
  textView_.autoresizingMask =
UIViewAutoresizingFlexibleWidth |
UIViewAutoresizingFlexibleHeight;
  textView_.text =
@"此文本可编辑。";
  [self.view
addSubview:textView_];

  // 在工具条中追加按钮
  UIBarButtonItem* hasTextButton =
    [[[UIBarButtonItem
alloc] initWithTitle:@"hasText"
                                      style:UIBarButtonItemStyleBordered
                                     target:self
                                     action:@selector(hasTextDidPush)]
autorelease];
  UIBarButtonItem* selectionButton =
    [[[UIBarButtonItem
alloc] initWithTitle:@"selection"
                                      style:UIBarButtonItemStyleBordered
                                     target:self
                                     action:@selector(selectionDidPush)]
autorelease];
  UIBarButtonItem* alignmentButton =
    [[[UIBarButtonItem
alloc] initWithTitle:@"alignment"
                                      style:UIBarButtonItemStyleBordered
                                     target:self
                                     action:@selector(alignmentDidPush)]
autorelease];
  UIBarButtonItem* scrollButton =
    [[[UIBarButtonItem
alloc] initWithTitle:@"top"
                                      style:UIBarButtonItemStyleBordered
                                     target:self
                                     action:@selector(scrollDidPush)]
autorelease];
  NSArray* buttons = [NSArray
arrayWithObjects:hasTextButton, selectionButton, alignmentButton, scrollButton,
nil];
  [self
setToolbarItems:buttons animated:YES];
}

- (void)viewDidAppear:(BOOL)animated {
  [super
viewDidAppear:animated];

  // 调整工具条位置
  [UIView
beginAnimations:nil
context:nil];
  [UIView
setAnimationDuration:0.3];
  textView_.frame =
    CGRectMake(
0, 0,
self.view.bounds.size.width,
self.view.bounds.size.height
- kKeyboardHeight );
  CGRect toolbarFrame =
self.navigationController.toolbar.frame;
  toolbarFrame.origin.y =
    self.view.window.bounds.size.height
- toolbarFrame.size.height -
kKeyboardHeight;
  self.navigationController.toolbar.frame
= toolbarFrame;
  [UIView
commitAnimations];
  [textView_
becomeFirstResponder]; //<
画面显示时显示键盘
}

- (void)viewWillDisappear:(BOOL)animated {
  [super
viewWillDisappear:animated];

  // 恢复工具条
  [UIView
beginAnimations:nil
context:nil];
  [UIView
setAnimationDuration:0.3];
  textView_.frame =
self.view.bounds;
  CGRect toolbarFrame =
self.navigationController.toolbar.frame;
  toolbarFrame.origin.y =
self.view.window.bounds.size.height
- toolbarFrame.size.height;
  self.navigationController.toolbar.frame
= toolbarFrame;
  [UIView
commitAnimations];
  [textView_
resignFirstResponder]; //<
画面隐藏时隐藏键盘
}

- (void)hasTextDidPush {
  UIAlertView* alert = [[[UIAlertView
alloc] init]
autorelease];
  if (
textView_.hasText ) {
    alert.message =
@"textView_.hasText = YES";
  } else {
    alert.message =
@"textView_.hasText = NO";
  }
  [alert addButtonWithTitle:@"OK"];
  [alert show];
}

- (void)selectionDidPush {
  UIAlertView* alert = [[[UIAlertView
alloc] init]
autorelease];
  alert.message = [NSString
stringWithFormat:@"location = %d, length = %d",
                    textView_.selectedRange.location,
textView_.selectedRange.length];
  [alert addButtonWithTitle:@"OK"];
  [alert show];
}

- (void)alignmentDidPush {
  textView_.editable =
NO;
  if (
UITextAlignmentRight < ++textView_.textAlignment ) {
    textView_.textAlignment =
UITextAlignmentLeft;
  } 
  textView_.editable =
YES;
}

- (void)scrollDidPush {
  // NSRange scrollRange = NSMakeRange( 0, 1 );
  [textView_
scrollRangeToVisible:NSMakeRange(
0, 1 )];
}