Question

我尝试使用xamarin ide（c＃）以编程方式创建按钮。我需要用什么代码来创建按钮，设置其大小，设置文本，设置背景颜色以及设置约束？有没有办法将按钮定义为屏幕宽度的1/4？提前致谢。

Answer 1

首先创建按钮

UIButton button = new UIButton(); 
CGRect ScreenBounds = UIScreen.MainScreen.Bounds;
float buttonWidth = (float)ScreenBounds.X / 4;
button.Frame = new CGRect (0f, 0f, buttonWidth, 50f); 
button.SetTitle ("Title", UIControlState.Normal);
button.BackgroundColor = UIColor.Green;

然后将其作为子视图添加到活动视图

this.AddSubview (button);

添加TouchUpInside

的活动

button.TouchUpInside += (object sender, System.EventArgs e) => {
   Debug.WriteLine( "Button Clicked!");
};

Answer 2

试试这个：

public class CalendarButton: UIButton
{

    public int ID;
    public int State;
    public CalendarButton (string text, int id)
    {
        ID = id;
        SetTitle (text, UIControlState.Normal);
    }
    public CalendarButton ():base(UIButtonType.System){
        State = 0;
    }
    public CalendarButton(IntPtr handle) : base(handle) { }
}

和这个自定义视图：

public class PickerView: UIView
{

int _numberItemPerRow = 7;
int _numberRows = 6;
nfloat _itemSize = 40;

UIColor _labelColor;
UIColor _oneTouchColor;
UIColor _twoTouchColor;
List<CalendarButton> _buttons;

public PickerView (UIColor lb, UIColor one, UIColor two)
{
    _labelColor = lb;
    _oneTouchColor = one;
    _twoTouchColor = two;
}
public PickerView(IntPtr handle) : base(handle) {

}


public override void Draw (CoreGraphics.CGRect rect)
{
    var height = CalculateHeight (rect.Width);
    this.Frame = new CoreGraphics.CGRect (rect.X, rect.Y, rect.Width, height);
    InitLayout ();
}

public override void SetNeedsLayout ()
{
    base.SetNeedsLayout ();
}

/*
 * Internal functions
 */

nfloat CalculateHeight(nfloat width)
{
    _itemSize = width / 7;
    return (nfloat)(_itemSize * (_numberRows + 1) + 70);
}

void InitLayout ()
{
    DateTime currentTime = DateTime.Now;
    // add date label - first row
    for (int i = 0; i < 7; i++) {
        UILabel lb = new UILabel ();
        lb.Frame = new CoreGraphics.CGRect (i * _itemSize, 0, _itemSize, _itemSize);
        lb.Text = Constants.DaysInWeek.ElementAt (i);
        lb.TextAlignment = UITextAlignment.Center;
        lb.ClipsToBounds = true;
        lb.Layer.CornerRadius = _itemSize / 2;
        lb.BackgroundColor = _labelColor;
        lb.Layer.BorderWidth = 1;
        lb.Layer.BorderColor = UIColor.Black.CGColor;
        this.AddSubview (lb);
    }
    // add month
    UILabel lbMonth = new UILabel();
    lbMonth.Frame = new CoreGraphics.CGRect (0, _itemSize, this.Bounds.Width, 70);
    lbMonth.TextAlignment = UITextAlignment.Center;
    lbMonth.TextColor = UIColor.Black;
    lbMonth.Font = UIFont.BoldSystemFontOfSize (22);
    Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
    string[] monthNames = 
        System.Globalization.CultureInfo.CurrentCulture
            .DateTimeFormat.MonthGenitiveNames;

    lbMonth.Text = string.Format ("{0} {1}", monthNames[currentTime.Month], currentTime.Year);
    this.AddSubview (lbMonth);
    // draw the table
    UIView viewTable = new UIView();
    viewTable.BackgroundColor = UIColor.Clear;
    viewTable.Frame = new CoreGraphics.CGRect (0, _itemSize + 70, this.Bounds.Width, _itemSize * _numberRows);
    _buttons = new List<CalendarButton> ();

    for (int row = 0; row < _numberRows; row++) {
        for (int col = 0; col < _numberItemPerRow; col++) {
            CalendarButton btn = new CalendarButton ();
            btn.Frame = new CoreGraphics.CGRect (col * _itemSize, row * _itemSize, _itemSize, _itemSize);
            btn.BackgroundColor = UIColor.White; // default color;
            btn.Layer.BorderColor = UIColor.Black.CGColor;
            btn.Layer.BorderWidth = 1;
            btn.Layer.CornerRadius = _itemSize / 2;
            btn.Tag = 0;

            btn.SetTitleColor (UIColor.Black, UIControlState.Normal);
            _buttons.Add (btn);
            viewTable.AddSubview (btn);
        }
    }
    // get the first and last date of current month;
    DateTime nexMonth = currentTime.AddMonths(1);
    var startDate = new DateTime(nexMonth.Year, nexMonth.Month, 1);
    var endDate = startDate.AddMonths(1).AddDays(-1);
    int currentDateOfWeek = (int)startDate.Date.DayOfWeek;
    for (int i = 0; i < endDate.Day; i++) {
        CalendarButton btn = _buttons.ElementAt (currentDateOfWeek + i);
        btn.BackgroundColor = _labelColor;
        btn.SetTitle ((i + 1).ToString (), UIControlState.Normal);
        btn.ID = i + 1;
        btn.TouchUpInside += (object sender, EventArgs e) => {
            CalendarButton sd = (CalendarButton)sender;
            sd.Tag++;
            if (sd.Tag%3 == 0) {
                // gray
                sd.State = 0;
                sd.BackgroundColor = _labelColor;
            }else if(sd.Tag%3 == 1){
                // red
                sd.State = 1;
                sd.BackgroundColor = _oneTouchColor;
            }else{
                // green
                sd.State = 2;
                sd.BackgroundColor = _twoTouchColor;
            }
        };
    }
    this.AddSubview (viewTable);
}
}

结果：

view result

如何使用xamarin以编程方式制作按钮？

2 个答案: