iOS UI基础-10.0 QQ聊天布局之键盘及文本使用

/**
 *  返回一张可以随意拉伸不变形的图片
 *
 *  @param name 图片名字
 */
+ (UIImage *)resizableImage:(NSString *)name
{
    UIImage *normal = [UIImage imageNamed:name];
    CGFloat w = normal.size.width * 0.5;
    CGFloat h = normal.size.height * 0.5;
    return [normal resizableImageWithCapInsets:UIEdgeInsetsMake(h, w, h, w)];
}

   [self.textView setBackgroundImage:[UIImage resizableImage:@"chat_send_nor"] forState:UIControlStateNormal];

    //  设置文本框左边显示的view
    self.inputView.leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 8, 0)];
    // 永远显示
    self.inputView.leftViewMode = UITextFieldViewModeAlways;

@interface MJViewController () <UITextFieldDelegate>
@property (weak, nonatomic) IBOutlet UITextField *inputView;
@end

@implementation MJViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // 设置文本框代理
    self.inputView.delegate = self;
}

#pragma mark - 文本框代理
/**
 *  点击了return按钮(键盘最右下角的按钮)就会调用
 */
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    // 1.自己发一条消息
    [self addMessage:textField.text type:MJMessageTypeMe];
    
    // 2.自动回复一条消息
    NSString *reply = [self replayWithText:textField.text];
    [self addMessage:reply type:MJMessageTypeOther];
    
    // 3.清空文字
    self.inputView.text = nil;
    
    // 返回YES即可
    return YES;
}

    // 2.监听键盘的通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];

/**
 *  当键盘改变了frame(位置和尺寸)的时候调用
 */
- (void)keyboardWillChangeFrame:(NSNotification *)note
{
    // 设置窗口的颜色
    self.view.window.backgroundColor = self.tableView.backgroundColor;
    
    // 0.取出键盘动画的时间
    CGFloat duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    
    // 1.取得键盘最后的frame
    CGRect keyboardFrame = [note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    
    // 2.计算控制器的view需要平移的距离
    CGFloat transformY = keyboardFrame.origin.y - self.view.frame.size.height;
    
    // 3.执行动画
    [UIView animateWithDuration:duration animations:^{
        self.view.transform = CGAffineTransformMakeTranslation(0, transformY);
    }];
}

/**
 *  当开始拖拽表格的时候就会调用
 */
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    // 退出键盘
    [self.view endEditing:YES];
}