UITextView控件的用法详解

1.创建并初始化
创建UITextView的文件，并在.h文件中写入如下代码：

1 #import <UIKit/UIKit.h>
2 
3 @interface TextViewController : UIViewController <UITextViewDelegate>{
4       UITextView *textView;
5 }
6 
7 @property (nonatomic, retain) UITextView *textView; 
8 
9 @end

复制代码

在.m文件中初始化这个textview，写入代码如下：

 1 self.textView = [[[UITextView  alloc] initWithFrame:self.view.frame] autorelease]; //初始化大小并自动释放
 2 
 3 self.textView.textColor = [UIColor blackColor];//设置textview里面的字体颜色  
 4 
 5 self.textView.font = [UIFont fontWithName:@"Arial" size:18.0];//设置字体名字和字体大小  
 6 
 7 self.textView.delegate = self;//设置它的委托方法  
 8 
 9 self.textView.backgroundColor = [UIColor whiteColor];//设置它的背景颜色
10 
11 self.textView.text = @"Now is the time for all good developers to come to serve their country./n/nNow is the time for all good developers to come to serve their country.";//设置它显示的内容  
12 
13 self.textView.returnKeyType = UIReturnKeyDefault;//返回键的类型  
14 
15 self.textView.keyboardType = UIKeyboardTypeDefault;//键盘类型  
16 
17 self.textView.scrollEnabled = YES;//是否可以拖动  
18 
19 self.textView.autoresizingMask = UIViewAutoresizingFlexibleHeight;//自适应高度
20 
21 [self.view addSubview: self.textView];//加入到整个页面中 

复制代码

文本字段实现了UITextInputTrait协议，其提供了7个属性来定义字段处理文本输入的方式：autocapitalizationType、autocorrectionType、enablesReturnKeyAutomatically、keyboardAppearance、keyboardType、returnKeyType、secureTextEntry。

其它，当文本字段为空时，placeholder文本以浅灰色显示，提供一个用户提示。通过设置clearButtonMode可以指定是否以及何时显示清除按钮。
2. 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，当然要先实现UITextViewDelegate。

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

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

   self.navigationItem.rightBarButtonItem = done;        

}    

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

    self.navigationItem.rightBarButtonItem = nil;  

} 

- (void)leaveEditMode {

    [self.textView resignFirstResponder];   

} 

复制代码

（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。

#pragma mark - UITextView Delegate Methods     

-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{    

    if ([text isEqualToString:@"/n"]) {    

        [textView resignFirstResponder];    

        return NO;    

    }

    return YES;    

}

复制代码

（3）还有你也可以自定义其他视图控件加载到键盘上用来退出，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。

 1 UIToolbar * topView = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];  
 2 
 3     [topView setBarStyle:UIBarStyleBlack];  
 4 
 5     UIBarButtonItem * helloButton = [[UIBarButtonItem alloc]initWithTitle:@"Hello" style:UIBarButtonItemStyleBordered target:self action:nil];        
 6 
 7     UIBarButtonItem * btnSpace = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];  
 8 
 9       
10 
11     UIBarButtonItem * doneButton = [[UIBarButtonItem alloc]initWithTitle:@"Done" style:UIBarButtonItemStyleDone target:self action:@selector(dismissKeyBoard)];  
12 
13     NSArray * buttonsArray = [NSArray arrayWithObjects:helloButton,btnSpace,doneButton,nil];  
14 
15     [doneButton release];  
16 
17     [btnSpace release];  
18 
19     [helloButton release];  
20 
21     [topView setItems:buttonsArray];  
22 
23     [tvTextView setInputAccessoryView:topView];  
24 
25 -(IBAction)dismissKeyBoard  
26 
27 {  
28 
29     [tvTextView resignFirstResponder];  
30 
31 }

复制代码