导读：
- 一、创建UITextField
- 二、设置UITextField的leftView/rightView
- 三、UITextField的常用设置
- 四、键盘回收
- 五、键盘通知
一、创建UITextField
-
UITextField 是UIControl的子类，UIControl又是UIView的子类，所以也是一个视图，只不过比UIView多了两个功能:1.文字显示，2.文本编辑。
-
UITextField *text = [[UITextField alloc] int];
text.frame = CGRectMake(50, 50, 180, 50)];
text.backgroundColor = [UIColor yellowColor];
[self.view addSubview:text];
二、设置UITextField的leftView/rightView
UIImageView *leftView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"icon"]];
leftView.frame = CGRectMake(0, 0, 55, 20);
leftView.contentMode = UIViewContentModeCenter;
self.textField.leftViewMode = UITextFieldViewModeAlways;
self.textField.leftView = leftView;
三、UITextField的常用设置
- UITextField不支持文字换行
- 设置text右侧清除按钮
self.textField.clearButtonMode = UITextFieldViewModeAlways;
- 设置text的边框样式(圆角)
text.borderStyle = UITextBorderStyleRoundedRect;
- 设置text默认显示文字(但是不作为文本内容的一部分)
text.placeholder = @"请输入用户名";
- 设置text文字
text.text = @"什么破烂”;
- 设置文本颜色
text.textColor = [UIColor blackColor];
- 设置文本的对齐方式
text.textAlignment = NSTextAlignmentCenter;
- 设置文字字体
text.font = [UIFont systemFontOfSize:18];
- 设置输入框是否可编辑
text.enabled = YES;
- 设置当开始编辑时,是否清除框中内容
text.clearsOnBeginEditing = YES;
- 设置密码格式(输入框中内容是否以点的形式显示)
text.secureTextEntry = YES;
- 设置弹出键盘的样式(数字键盘)
text.keyboardType = UIKeyboardTypeNumberPad;
- 键盘右下角显示样式
text.returnKeyType = UIReturnKeyGo;
- 设置tag值
text.tag = 120;
三、键盘回收
- 点击右下角或者回车回收键盘
1. 遵守协议：@interface ViewController ()<UITextFieldDelegate>
2. 设置代理：text.delegate = self；
3. 实现协议中的方法：
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
return YES;
}
- 点击空白处回收键盘
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
[self.textField resignFirstResponder];
}
四、键盘通知
//在view即将显示时添加对系统发出的键盘通知的监听
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
//为当前控制器注册键盘弹起和关闭通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(openKeyboard:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(closeKeyboard:) name:UIKeyboardWillHideNotification object:nil];
}
/** 在view即将消失时取消键盘通知的监听 */
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}
/** 键盘弹起事件 */
- (void)openKeyboard:(NSNotification *)notification
{
NSLog(@"%@",notification.userInfo);
}
/** 键盘关闭事件 */
-(void)closeKeyboard:(NSNotification *)notification
{
NSLog(@"关闭了键盘");
}
/** 点击空白处回收键盘 */
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
[self.view endEditing:YES];
}
/** 销毁通知 */
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
