Objective-C UITextView的使用方法

//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];

}

    原文作者:炸街程序猿
    原文地址: https://www.jianshu.com/p/970958c90c46
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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