UITextView - 更改将要输入文本的富文本属性

@property(nonatomic,copy) NSDictionary<NSString *, id> *typingAttributes NS_AVAILABLE_IOS(6_0); // automatically resets when the selection changes

-(BOOL)textViewShouldBeginEditing:(UITextView *)textView{
    NSMutableDictionary *dic1 = [NSMutableDictionary dictionaryWithDictionary:textView.typingAttributes];
    NSMutableParagraphStyle *para = [[NSMutableParagraphStyle alloc] init];
    para.lineBreakMode = NSLineBreakByCharWrapping;
    [dic1 setValue:para forKey:NSParagraphStyleAttributeName];
    textView.typingAttributes = dic1;
    return YES;
}