iOS实现TextView提示文字并且输入字数限制
实现TextView提示文字并且输入字数限制的反馈意见功能-----非常简洁明了！如图实现页面，效果如下：
1.输入文字的时候提示文字消失，TextView没有文字的时候提示文字显示；
2.右下角实时显示字数；
3.字数到达指定限制后，TextView不能输入更多，可以删除；
4.提交按钮在TextView不为空的时候按钮为绿色且可点击；TextView为空时，为灰色状态且不可点击。
.m中的代码如下：
#import "YJFeedBackViewController.h"
@interface YJFeedBackViewController ()<UITextViewDelegate>
@property (weak, nonatomic) IBOutlet UILabel *placeHolder;
@property (weak, nonatomic) IBOutlet UIButton *commitButton;
@property (weak, nonatomic) IBOutlet UITextView *feedBackTextView;
@property (weak, nonatomic) IBOutlet UILabel *stirngLenghLabel;
@end
@implementation YJFeedBackViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.title = @"反馈意见";
self.automaticallyAdjustsScrollViewInsets = NO;
self.feedBackTextView.delegate = self;
self.placeHolder.userInteractionEnabled = NO;
self.commitButton.userInteractionEnabled = NO;
self.feedBackTextView.layer.borderWidth = 0.5;
self.feedBackTextView.layer.borderColor = [UIColor lightGrayColor].CGColor;
// Do any additional setup after loading the view from its nib.
}
//正在改变
- (void)textViewDidChange:(UITextView *)textView
{
FDLog(@"%@", textView.text);
self.placeHolder.hidden = YES;
//允许提交按钮点击操作
self.commitButton.backgroundColor = FDMainColor;
self.commitButton.userInteractionEnabled = YES;
//实时显示字数
self.stirngLenghLabel.text = [NSString stringWithFormat:@"%lu/100", (unsigned long)textView.text.length];
//字数限制操作
if (textView.text.length >= 100) {
textView.text = [textView.text substringToIndex:100];
self.stirngLenghLabel.text = @"100/100";
}
//取消按钮点击权限，并显示提示文字
if (textView.text.length == 0) {
self.placeHolder.hidden = NO;
self.commitButton.userInteractionEnabled = NO;
self.commitButton.backgroundColor = [UIColor lightGrayColor];
}
}