在CustomRenderer中获取控件的尺寸（Xamarin.Forms iOS）

Question

我在自定义EntryRenderer中覆盖了OnElementChanged方法，如下所示：

Dim listOfValues AS List(Of String) = new List(Of String)
        For Each item As ListItem In ddLokasi.Items
            If item.Selected Then
                listOfValues.Add(item.Value)
            End If
        Next

我想要做的就是自定义Entry控件以在左侧添加FontAwesome图标并在底部添加一个图层，使其看起来只有底边框。

问题是protected override void OnElementChanged(ElementChangedEventArgs<Entry> e) { base.OnElementChanged(e); if (Control != null) { var iconLabel = new UILabel(); iconLabel.Font = FontAwesome.Font(12); iconLabel.Text = " " + FontAwesome.FAPlay; iconLabel.Frame = new CGRect(x: 5, y: 0, width: 20, height: 20); Control.LeftView = iconLabel; Control.LeftViewMode = UITextFieldViewMode.Always; Control.BorderStyle = UITextBorderStyle.None; var bottomLine = new CALayer(); bottomLine.Frame = new CGRect(0.0, Control.Frame.Height - 1, Control.Frame.Width, 1.0); bottomLine.BackgroundColor = UIColor.White.CGColor; Control.Layer.AddSublayer(bottomLine); } } 没有Control.Frame＆amp; Width（他们的值为0）。

任何帮助或其他方式破解边框底部条目（UITextField）样式？ 提前谢谢。

Answer 1

  

我想要做的就是自定义Entry控件以在左侧添加FontAwesome图标并在底部添加一个图层，使其看起来只有底边框。

使用添加为控件UIView的彩色Subview，将为您处理裁剪。

： - ）

if (Control != null) {
    Control.BackgroundColor = UIColor.LightGray;
    var iconLabel = new UILabel();
    iconLabel.Font = FontAwesome.Font(12);
    iconLabel.Text = " " + FontAwesome.FAAmbulance;
    iconLabel.Frame = new CGRect(x: 5, y: 0, width: 20, height: 20);
    Control.LeftView = iconLabel;
    Control.LeftViewMode = UITextFieldViewMode.Always;

    Control.BorderStyle = UITextBorderStyle.None;
    Console.WriteLine ("cs: " + customSize);
    UIView myBox = new UIView (new CGRect (0.0, 20.0, 1000.0, 1.0)); 
    myBox.BackgroundColor = UIColor.Red;
    Control.AddSubview(myBox);
}

if (Control != null) {
    var iconLabel = new UILabel();
    iconLabel.Font = FontAwesome.Font(12);
    iconLabel.Text = " " + FontAwesome.FAPlay;
    iconLabel.Frame = new CGRect(x: 5, y: 0, width: 20, height: 20);
    Control.LeftView = iconLabel;
    Control.LeftViewMode = UITextFieldViewMode.Always;

    Control.BorderStyle = UITextBorderStyle.None;
    Console.WriteLine ("cs: " + customSize);
    UIView myBox = new UIView (new CGRect (0.0, 20.0, 1000.0, 1.0)); 
    myBox.BackgroundColor = UIColor.Black;
    Control.AddSubview(myBox);
}