iOS界面编程-UITextView

一、介绍

   继承关系：NSObject  《－UIResponder《－UIView《－UIScrollView《－UITextView，UITextView可以输入多行文字，并且继承自scrollview表明还可以滑动显示。iOS6之后可以使用attributedText属性，为一段文字设置多种类型。

二、相关方法和属性

1、初始化方法，创建一个textview

- (instancetype nonnull)initWithFrame:(CGRect)frame textContainer:(NSTextContainer * nullable)textContainer

2、配置文字属性

@property(nonatomic,
copy)
NSString * __null_unspecified
text

@property(copy)

NSAttributedString * __null_unspecified
attributedText
@property(nonatomic,
strong)
UIFont *font 字体 

@property(nonatomic,
strong)
UIColor *textColor 文字颜色

@property(nonatomic,
getter=isEditable)
BOOL editable  设置UITextView是否可以编辑

@property(nonatomic)
BOOL allowsEditingTextAttributes
@property(nonatomic)

UIDataDetectorTypes dataDetectorTypes
@property(nonatomic)

UIDataDetectorTypes dataDetectorTypes
@property(nonatomic)

NSTextAlignment textAlignment
@property(nonatomic,
copy)
NSDictionary <NSString *,id> *typingAttributes
@property(nonatomic,
copy)
NSDictionary <NSString *,id> *
__null_unspecified linkTextAttributes
3.选择操作

@property(nonatomic)

NSRange selectedRange
- (void)scrollRangeToVisible:(NSRange)range
滑动到指定区域

@property(nonatomic)
BOOL clearsOnInsertion  

@property(nonatomic,
getter=isSelectable)
BOOL selectable
4、访问委托

@property(nonatomic,
weak) id<

UITextViewDelegate > delegate
5、访问text kit对象
@property(nonatomic,
readonly)
NSLayoutManager *layoutManager
@property(nonatomic,
readonly)
NSTextContainer *textContainer
@property(nonatomic,
readonly, strong)

NSTextStorage *textStorage

三、实际例子

UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(10, textField.frame.origin.y + 31 + 10, self.view.frame.size.width - 20, 80)];
textView.backgroundColor = [UIColor redColor];
textView.text =@"test hello lil i\ns a label!this is a l\nabel!this this this is a label!this is a label!this is a label!this is a \n\nlabel!this this this is a \nlabel!this is a label!!this this this is a label!this is a label!this is a label!this is a label!this this this is a label!this is a labely and lucyafsffasdf";
textView.textColor = [UIColor blackColor];
textView.textAlignment = NSTextAlignmentRight;
textView.editable = YES;
textView.selectedRange = NSMakeRange(0, 5);
textView.delegate = self;
[textView scrollRangeToVisible:NSMakeRange(190, 5)];
textView.keyboardType = UIKeyboardTypeEmailAddress;
textView.clearsOnInsertion = YES;
textView.returnKeyType = UIReturnKeyGo;
// textView.selectable = YES;
// textView.inputView = button;
textView.inputAccessoryView = button;
[self.view addSubview:textView];UITextViewDelegate方法
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView;<span style="font-family: Arial, Helvetica, sans-serif;">//将要开始编辑</span>
- (BOOL)textViewShouldEndEditing:(UITextView *)textView;<span style="font-family: Arial, Helvetica, sans-serif;">//将要结束编辑</span>
- (void)textViewDidBeginEditing:(UITextView *)textView; <span style="font-family: Arial, Helvetica, sans-serif;">//开始编辑</span>
- (void)textViewDidEndEditing:(UITextView *)textView;<span style="font-family: Arial, Helvetica, sans-serif;">//结束编辑</span>
//内容将要发生改变编辑
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;

//内容发生改变编辑
- (void)textViewDidChange:(UITextView *)textView;

//焦点发生改变
- (void)textViewDidChangeSelection:(UITextView *)textView;


控件自适应输入的文本的内容的高度，可在textViewDidChange的代理方法中加入调整控件大小的代理即可
- (void)textViewDidChange:(UITextView *)textView{
//计算文本的高度
CGSize constraintSize;
constraintSize.width = textView.frame.size.width-16;
constraintSize.height = MAXFLOAT;
CGSize sizeFrame =[textView.text sizeWithFont:textView.font
constrainedToSize:constraintSize
lineBreakMode:UILineBreakModeWordWrap];

//重新调整textView的高度
textView.frame =CGRectMake(textView.frame.origin.x,textView.frame.origin.y,textView.frame.size.width,sizeFrame.height+5);
}

控制输入文字的长度和内容，可通调用以下代理方法实现
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if (range.location>=100)
{
//控制输入文本的长度
return  NO;
}
if ([text isEqualToString:@"\n"]) {
//禁止输入换行
return NO;
}
else
{
return YES;
}
}

UITextView退出键盘的几种方式
1）如果你程序是有导航条的，可以在导航条上面加多一个Done的按钮，用来退出键盘，当然要先实UITextViewDelegate。

- (void)textViewDidBeginEditing:(UITextView *)textView {

UIBarButtonItem *done =    [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone
target:self
action:@selector(dismissKeyBoard)];

self.navigationItem.rightBarButtonItem = done;

[done release];
done = nil;

}

- (void)textViewDidEndEditing:(UITextView *)textView {
self.navigationItem.rightBarButtonItem = nil;
}

- (void)dismissKeyBoard {
[self.textView resignFirstResponder];
}

2）如果你的textview里不用回车键，可以把回车键当做退出键盘的响应键。

-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if ([text isEqualToString:@"\n"]) {
[textView resignFirstResponder];
return NO;
}
return YES;
}

3）还有你也可以自定义其他加载键盘上面用来退出，比如在弹出的键盘上面加一个view来放置退出键盘的Done按钮。
代码如下：

UIToolbar * topView = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];
[topView setBarStyle:UIBarStyleBlack];

UIBarButtonItem *btnSpace = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace
target:self
action:nil];
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc]initWithTitle:@"Done"
style:UIBarButtonItemStyleDone
target:self
action:@selector(dismissKeyBoard)];
NSArray * buttonsArray = @[btnSpace, doneButton];;
[topView setItems:buttonsArray];
[textView setInputAccessoryView:topView];//当文本输入框加上topView

-(IBAction)dismissKeyBoard
{
[tvTextView resignFirstResponder];
}