MonoTouch.Dialog:如何设置EntryElement的字符数限制

Question

我找不到如何限制字符数 EntryElement

Answer 1

我也喜欢继承和事件:-)试试这个:

class MyEntryElement : EntryElement {

    public MyEntryElement (string c, string p, string v) : base (c, p, v)
    {
        MaxLength = -1;
    }

    public int MaxLength { get; set; }

    static NSString cellKey = new NSString ("MyEntryElement");      
    protected override NSString CellKey { 
        get { return cellKey; }
    }

    protected override UITextField CreateTextField (RectangleF frame)
    {
        UITextField tf = base.CreateTextField (frame);
        tf.ShouldChangeCharacters += delegate (UITextField textField, NSRange range, string replacementString) {
            if (MaxLength == -1)
                return true;

            return textField.Text.Length + replacementString.Length - range.Length <= MaxLength;
        };
        return tf;
    }
}

还可以在这里阅读Miguel的警告(编辑到我的帖子):MonoTouch.Dialog:设置EntryElement的条目对齐