iOS UITextView 高度随文字自动增加，并跟随键盘移动（一）

项目中遇到这样一个需求 ，有个文本框，需要随着用户输入的文字多少高度自动增加。

比如说，当用户输入的文字不足一行的时候textview的高度为初始高度，

当输入的文字超过一行，不足两行的时候，我们将textView 的高度调整为显示两行文字的高度。

此处，我们要实现一个评论的功能，还需要输入框跟随键盘移动。

开始代码

首先，我们新建一个类，专门管理输入框，我们起名：CommentView 继承 UIView

为他创建一个UITextView （我们的输入框）

#import <UIKit/UIKit.h>

@interface CommentView : UIView

@property(nonatomic,strong) UITextView *textView;

-(void)inittextFrame;

@end

接下来我们在实现类中 初始化输入框

//获取屏幕 宽度、高度
#define SCREEN_FRAME ([UIScreen mainScreen].bounds)
#define SCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)
#define SCREEN_HEIGHT ([UIScreen mainScreen].bounds.size.height)

#import "CommentView.h"

@implementation CommentView

-(id)initWithFrame:(CGRect)frame
{

    self=[super initWithFrame:frame];
    if (self) {
        self.backgroundColor=[UIColor blueColor];
        [self initTextView:frame];
    }
    return self;
}
-(void)initTextView:(CGRect)frame
{

    self.textView=[[UITextView alloc]initWithFrame:CGRectMake(2, 2, SCREEN_WIDTH-2*2, frame.size.height-2*2)];

    self.textView.backgroundColor=[UIColor colorWithRed:233.0/255 green:232.0/255 blue:250.0/255 alpha:1.0];
    [self addSubview:self.textView];

}

@end

我们先添加一下 CommentView  看出来的效果

我们添加一个按钮，当点击按钮的时候 打开ComentView

//获取屏幕 宽度、高度
#define SCREEN_FRAME ([UIScreen mainScreen].bounds)
#define SCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)
#define SCREEN_HEIGHT ([UIScreen mainScreen].bounds.size.height)

#import "ViewController.h"
#import "CommentView.h"

@interface ViewController ()
{

    CommentView *commentV;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    UIButton *testBtn=[[UIButton alloc]initWithFrame:CGRectMake(10, 120, 88, 36)];
    [testBtn setTitle:@"testBtn" forState:UIControlStateNormal];
    [testBtn setTitleColor:[UIColor greenColor] forState:UIControlStateNormal];
    [testBtn addTarget:self action:@selector(OpentestView) forControlEvents:UIControlEventTouchDown];
    [self.view addSubview:testBtn];
}

-(void)OpentestView
{

    commentV=[[CommentView alloc]initWithFrame:CGRectMake(0, SCREEN_HEIGHT-40, SCREEN_WIDTH, 40)];
    [self.view addSubview:commentV];

}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

运行，点击button 弹出CommentView 效果如下

接下来 我们让文本框跟随键盘

我们在打开ContentView 打开键盘

然后添加键盘打开和关闭的通知，监听到通知后，调整CommentView的位置

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardHide:) name:UIKeyboardWillHideNotification object:nil];

#pragma mark keyboardNotification
-(void)keyboardShow:(NSNotification *)note
{
    CGRect keyBoardRect=[note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGFloat deltaY=keyBoardRect.size.height;
    [UIView animateWithDuration:[note.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue] animations:^{
        commentV.transform=CGAffineTransformMakeTranslation(0, -deltaY);
    }];
}
-(void)keyboardHide:(NSNotification *)note
{
    [UIView animateWithDuration:[note.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue] animations:^{
        commentV.transform=CGAffineTransformIdentity;
    } completion:^(BOOL finished) {
        [email protected]"";
        [commentV removeFromSuperview];
    }];
}

我们测试一下 效果

好了到目前为止，键盘调用，文本框跟随键盘基本实现。

下一节我们来实现文本框自动调节高度。

下节地址 http://blog.csdn.net/lwjok2007/article/details/47403511

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