先设置UITextField addTarget
-(void)nameFieldChange:(UITextField *)textField{
if ([textField.text isIncludingEmoji]) {
textField.text = [textField.text removedEmojiString];
}
if ([textField.text isIncludingNumber]) {
textField.text = [textField.text removedNumberString];
}
NSString *toBeString = textField.text;
NSString *lang = [[UITextInputMode currentInputMode] primaryLanguage]; // 键盘输入模式
if ([lang isEqualToString:@"zh-Hans"]) { // 简体中文输入，包括简体拼音，健体五笔，简体手写
UITextRange *selectedRange = [textField markedTextRange];
//获取高亮部分
UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];
// 没有高亮选择的字，则对已输入的文字进行字数统计和限制
if (!position) {
if (toBeString.length > 4) {
textField.text = [toBeString substringToIndex:4];
}
}
// 有高亮选择的字符串，则暂不对文字进行统计和限制
else{
}
}
// 中文输入法以外的直接对其统计限制即可，不考虑其他语种情况
else{
if (toBeString.length > 4) {
textField.text = [toBeString substringToIndex:4];
}
}
}
eg：设置UITextField的占位文字和箭头的颜色
[textField setValue:color forKeyPath:@"_placeholderLabel.textColor"];
textField.tintColor = [UIColor redColor];
设置clearButton的样式
UIButton *clearBtn = [textField valueForKey:@"_clearButton"];
[clearBtn setImage:[UIImage imageNamed:@"close"] forState:(UIControlStateNormal)];
