UITextView

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
把键盘的回车键当初键盘弹回按钮
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;   

}
对textView字数限制
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text   
{   
    if (range.location>=100)    
    {   
        return  NO;   
    }   
    else    
    {   
        return YES;   
    }   

}

2. UITextView退出键盘的几种方式

因为你点击UITextView会出现键盘，如果你退出键盘，有如下几种方式：

（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。

代码如下：

- (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];

}

 

（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。
代码如下：

#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;
}

 

这样无论你是使用电脑键盘上的回车键还是使用弹出键盘里的return键都可以达到退出键盘的效果。

（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 * helloButton = [[UIBarButtonItem alloc]initWithTitle:@"Hello" style:UIBarButtonItemStyleBordered target:self action:nil];
    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 = [NSArray arrayWithObjects:helloButton,btnSpace,doneButton,nil];
    [doneButton release];
    [btnSpace release];
    [helloButton release];
    [topView setItems:buttonsArray];
    [tvTextView setInputAccessoryView:topView];
-(IBAction)dismissKeyBoard
{
    [tvTextView resignFirstResponder];
}

 

（4）设置UITextView圆角问题

做法是在 #import QuartzCore/QuartzCore.h 后，便能調用 [textView.layer setCornerRadius:10]; 來把 UITextView 设定圓角

（5）UITextView根据文本大小自适应高度

通过实现文本字数来确定高度，如下：

NSString * desc = @"Description it is  a test font, and don't become angry for which i use to do here.Now here is a very nice party from american or not!";
CGSize  size = [desc sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake(240, 2000) lineBreakMode:UILineBreakModeWordWrap];

 

然后需要定义UITextView的numberoflines为0，即不做行数的限制。如下：

[textView setNumberOfLines:0];
[textView setFrame:CGRectMake(40, 135, 240, size.height+10)];
[textView setText:desc];

 

 

（6）UITextView自定选择文字后的菜单

在ViewDidLoad中加入：

UIMenuItem *menuItem = [[UIMenuItem alloc]initWithTitle:@"分享到新浪微博" action:@selector(changeColor:)];
UIMenuController *menu = [UIMenuController sharedMenuController];
[menu setMenuItems:[NSArray arrayWithObject:menuItem]];
[menuItem release];

 

 

当然上面那个@selector里面的changeColor方法还是自己写吧，也就是说点击了我们自定义的菜单项后会触发的方法。

然后还得在代码里加上一个方法：

-(BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
if(action == @selector(changeColor:))
{
if(textView.selectedRange.length>0)
return YES;
}
return NO;
}

 

实现后如下图：

一、给UITextView绘制圆角，通过QuartzCore框架，操作CALayer可以给UITextView绘制圆角边框。
       textView.layer.cornerRadius = 6
       textView.layer.masksToBounds = YES
通过cornerRadius可设置圆角弧度。
 
二、UITextView和UIImageView组合，将背景图片制作好加载进UIImageView。
      CGRect imageViewFrame = CGRectMake(30.0,100.0,240.0,90.0);
      UIImageView *imageView = [[UIImageView alloc] initWithFrame:imageViewFrame];
      imageView.image = [UIImage imageNamed:@"background.png"];
      imageView.userInteractionEnabled = YES;
      CGRect textViewFrame = CGRectMake(5.0,5.0,230.0,80.0);
      UITextView *textView = [[UITextView alloc] initWithFrame:textViewFrame];
      textView.backgroundColor = [UIColor clearColor];
      [imageView addSubview:textView];
设置imageView.userInteractionEnabled = YES,让textView响应触碰事件。
 
三、设置UITextView背景图片，在UITextView区域内。
      CGRect textViewFrame = CGRectMake(30.0,100.0,240.0,90.0);
      UITextView *textView = [[UITextView alloc] initWithFrame:textViewFrame];      
      UIImageView *imageView = [[UIImageView alloc] initWithFrame:[textView bounds]];
      imageView.image = [UIImage imageNamed:@"background.png"];
      [textView addSubview:imageView];
      [textView sendSubviewToBack:imageView];