ios开发之--实现TextView提示文字并且输入字数限制

实现字数控制和限制，并展示当前输入的字符串长度，以及按钮的点击状态，代码如下：

1，设置代理

@interface FKViewController ()<UITextViewDelegate>
@property (weak, nonatomic) IBOutlet UITextView *FKTextView;
@property (weak, nonatomic) IBOutlet UILabel *descLab;
@property (weak, nonatomic) IBOutlet UIButton *sendBtn;
@property (weak, nonatomic) IBOutlet UILabel *stringlenghtLab;

2，设置初始状态

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

self.view.backgroundColor = BackgroundColor;
self.navigationController.navigationBarHidden = YES;
CustomNavigationBar *nav = [[CustomNavigationBar alloc]initWithFrame:CGRectMake(0, 0, KscreenW, NavHeight) withTitle:@"意见反馈" withLeftBtnHidden:NO withRightBtn:YES];
nav.delegate = self;
[self.view addSubview:nav];

self.FKTextView.delegate = self;
self.descLab.userInteractionEnabled = NO;
self.sendBtn.userInteractionEnabled = NO;
self.sendBtn.backgroundColor = [UIColor lightGrayColor];
}

3，代理方法的实现

-(void)textViewDidChange:(UITextView *)textView
{
self.descLab.hidden = YES;
self.sendBtn.userInteractionEnabled = YES;
self.sendBtn.backgroundColor = MainColor;
//实时显示字数
self.stringlenghtLab.text = [NSString stringWithFormat:@"%ld/100",(long)textView.text.length];

//字数限制
if (textView.text.length >= 100) {
textView.text = [textView.text substringToIndex:100];
}

//取消安润点击权限，并显示文字
if (textView.text.length == 0) {
self.descLab.hidden = NO;
self.sendBtn.userInteractionEnabled = NO;
self.sendBtn.backgroundColor = [UIColor lightGrayColor];
}
}

字符串长度为0时，按钮返回初始状态，有输入字符时，显示为可点击状态，很简单，仅做记录用！