iOS开发－UITextView的用法及技巧(ios7下光标bug解决方案)

来源：互联网发布：迈乐网络电视机顶盒编辑：程序博客网时间：2024/06/05 04:14

一、新建一个textView

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//初始化
UITextView *textView = [[[UITextView alloc] init] autorelease];
 
//设置代理 需在interface中声明UITextViewDelegate
textView.delegate = self;
 
//字体大小
textView.font = [UIFont systemFontOfSize:16];
 
//添加滚动区域
textView.contentInset = UIEdgeInsetsMake(-11, -6, 0, 0);
 
//是否可以滚动
textView.scrollEnabled = NO;
 
//获得焦点
[textView becomeFirstResponder];

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[self.view addSubview:textView];

二、键盘操作

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//返回键的类型
textView.returnKeyType = UIReturnKeyDefault;
 
//键盘类型
textView.keyboardType = UIKeyboardTypeDefault;

三、隐藏键盘的几种方式

个人还是认为最方便的是在键盘上加上一个ToolBar，在上面加上一个按钮来隐藏键盘

①在键盘上加上隐藏按钮

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//定义一个toolBar
UIToolbar * topView = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];
 
//设置style
[topView setBarStyle:UIBarStyleBlack];
 
//定义两个flexibleSpace的button，放在toolBar上，这样完成按钮就会在最右边
UIBarButtonItem * button1 =[[UIBarButtonItem  alloc]initWithBarButtonSystemItem:                                        UIBarButtonSystemItemFlexibleSpace target:self action:nil];
 
UIBarButtonItem * button2 = [[UIBarButtonItem  alloc]initWithBarButtonSystemItem:                                        UIBarButtonSystemItemFlexibleSpace target:self action:nil];
 
//定义完成按钮
UIBarButtonItem * doneButton = [[UIBarButtonItem alloc]initWithTitle:@"完成"style:UIBarButtonItemStyleDone  target:self action:@selector(resignKeyboard)];
     
//在toolBar上加上这些按钮
NSArray * buttonsArray = [NSArray arrayWithObjects:button1,button2,doneButton,nil];     
[topView setItems:buttonsArray];
 
[textView setInputAccessoryView:topView];

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//隐藏键盘
- (void)resignKeyboard {
    [textView resignFirstResponder];
}

最终效果

还有几种也可隐藏键盘的方式

②用回车键，前提是你的textView中不需要用到回车键

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-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
 if([text isEqualToString:@"\n"])
{
[textView resignFirstResponder]; returnNO; 
}
 returnYES; 
}

③触摸空白处隐藏键盘

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-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    //隐藏键盘
    [textView resignFirstResponder];
}

四、使键盘不挡住输入框

在view中添加一个子view，设置此子view的tag值为1000，在此view上添加一个textView和一个发送按钮，如下图；我们要达到textView的键盘弹出时，整个View往上平移，键盘消失，view往下平移的效果，模拟发送短信的界面。

设置textView圆角

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//设置textView圆角
[self.textView.layer setCornerRadius:10];

①、在viewWillAppear中添加键盘监听事件

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//添加键盘的监听事件
     
    //注册通知,监听键盘弹出事件
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
     
    //注册通知,监听键盘消失事件
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidHidden) name:UIKeyboardDidHideNotification object:nil];

②、完成①selector中键盘弹出keyboardDidShow:和消失keyboardDidHidden方法

在.m文件#import后面添加

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//动画时间
#define kAnimationDuration 0.2
//view高度
#define kViewHeight 56

键盘出现

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// 键盘弹出时
-(void)keyboardDidShow:(NSNotification *)notification
{
     
    //获取键盘高度
    NSValue *keyboardObject = [[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey];
     
    CGRect keyboardRect;
     
    [keyboardObject getValue:&keyboardRect];
     
    //调整放置有textView的view的位置
     
       //设置动画
    [UIView beginAnimations:nil context:nil];
     
       //定义动画时间
    [UIView setAnimationDuration:kAnimationDuration];
     
       //设置view的frame，往上平移
    [(UIView *)[self.view viewWithTag:1000] setFrame:CGRectMake(0, self.view.frame.size.height-keyboardRect.size.height-kViewHeight, 320, kViewHeight)];
     
    [UIView commitAnimations];
     
}

键盘消失

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//键盘消失时
-(void)keyboardDidHidden
{
    //定义动画
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:kAnimationDuration];
    //设置view的frame，往下平移
    [(UIView *)[self.view viewWithTag:1000] setFrame:CGRectMake(0, self.view.frame.size.height-kViewHeight, 320, kViewHeight)];
    [UIView commitAnimations];
}

效果图：

iOS7光标问题

PS：有网友遇到textView在ios7上出现编辑进入最后一行时光标消失，看不到最后一行，变成盲打，stackOverFlow网站上有大神指出，是ios7本身bug，加上下面一段代码即可（网友调试得出，在此mark一下，有问题，欢迎大神们指出）

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-(void)textViewDidChange:(UITextView *)textView {
    CGRect line = [textView caretRectForPosition:
                   textView.selectedTextRange.start];
    CGFloat overflow = line.origin.y + line.size.height
    - ( textView.contentOffset.y + textView.bounds.size.height
       - textView.contentInset.bottom - textView.contentInset.top );
    if( overflow > 0 ) {
        // We are at the bottom of the visible text and introduced a line feed, scroll down (iOS 7 does not do it)
        // Scroll caret to visible area
        CGPoint offset = textView.contentOffset;
        offset.y += overflow + 7; // leave 7 pixels margin
        // Cannot animate with setContentOffset:animated: or caret will not appear
        [UIView animateWithDuration:.2 animations:^{
            [textView setContentOffset:offset];
        }];
    }
}

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