自定義提示

/**
 獲取指定寬度width的字串在UITextView上的高度

 @param textView 待計算的UITextView
 @param width 限制字串顯示區域的寬度
 @return 返回的高度
 */
- (float)heightForString:(UITextView *)textView andWidth:(float)width {
    CGSize sizeToFit = [textView sizeThatFits:CGSizeMake(width, MAXFLOAT)];
    return sizeToFit.height
 
;
}
#pragma mark - 顯示提示資訊
- (void)toastTip:(NSString *)toastInfo {
    CGRect frameRC = [[UIScreen mainScreen] bounds];
    frameRC.origin.y = frameRC.size.height - 110;
    frameRC.size.height -= 110;
    __block UITextView *toastView = [[UITextView alloc] init];

    toastView.editable = NO;
    toastView.selectable
 
 = NO;

    frameRC.size.height = [self heightForString:toastView andWidth:frameRC.size.width];

    toastView.frame = frameRC;

    toastView.text = toastInfo;
    toastView.backgroundColor = [UIColor whiteColor];
    toastView.alpha = 0.5;

    [self.view addSubview:toastView];

    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 2
 
 * NSEC_PER_SEC);

    dispatch_after(popTime, dispatch_get_main_queue(), ^() {
        [toastView removeFromSuperview];
        toastView = nil;
    });
}