iOS UITextView加载本地html文件例子

有时候我们不是从服务器上直接加载一个网页，而是需要加载本地的html文件，具体实现的代码如下：

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    //创建从Bundle中来自HTML文件的URL
    NSURL *html = [[NSBundle mainBundle] URLForResource:@"right_obligations" withExtension:@"html"];
    
    // 用HTML创建attributedString
    NSAttributedString *attrStr = [[NSAttributedString alloc] initWithFileURL:html options:@{NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType} documentAttributes:nil error:nil];
    
    // 创建TextView，添加attributed str
    UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(0, kHeaderHeight, kScreenWidth, kScreenHeight - kHeaderHeight)];
    textView.editable = NO;
    [textView setAttributedText:attrStr];
    [self.view addSubview:textView];
}

补充:关于 UITextView用法

//初始化并定义大小  

 UITextView *textview = [[UITextView alloc] initWithFrame:CGRectMake(20, 10, 280, 30)];
    textview.backgroundColor=[UIColor whiteColor]; //背景色
    textview.scrollEnabled = NO;    //当文字超过视图的边框时是否允许滑动，默认为“YES”
    textview.editable = YES;        //是否允许编辑内容，默认为“YES”
    textview.delegate = self;       //设置代理方法的实现类
    textview.font=[UIFont fontWithName:@"Arial" size:18.0]; //设置字体名字和字体大小;
    textview.returnKeyType = UIReturnKeyDefault;//return键的类型
    textview.keyboardType = UIKeyboardTypeDefault;//键盘类型
    textview.textAlignment = NSTextAlignmentLeft; //文本显示的位置默认为居左
    textview.dataDetectorTypes = UIDataDetectorTypeAll; //显示数据类型的连接模式（如电话号码、网址、地址等）
    textview.textColor = [UIColor blackColor];
    textview.text = @"UITextView详解";//设置显示的文本内容
    [self.view addSubview:textview];

UITextView的代理方法如下:
//将要开始编辑
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView;

//将要结束编辑
- (BOOL)textViewShouldEndEditing:(UITextView *)textView;

//开始编辑
- (void)textViewDidBeginEditing:(UITextView *)textView;

//结束编辑
- (void)textViewDidEndEditing:(UITextView *)textView;

//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;

有时候我们要控件自适应输入的文本的内容的高度，只要在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
因为iphone的软键盘没有自带的退键盘键，所以要实现退出键盘需要自己实现，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。
 
- (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。
代码如下：

-(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];;
    [doneButton release];
    [btnSpace release];
    [topView setItems:buttonsArray];
    [textView setInputAccessoryView:topView];//当文本输入框加上topView
    [topView release];
    topView = nil;

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