Xamarin.iOS 代码中添加约束练习
Xamarin.iOS 代码中添加约束练习
在代码中通过约束,创建如下界面:
- CheckBox使用第三方库:BEMCheckBox
- 使用Visual Format Language(VFL)视图约束,规则参见iOS开发文档:https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/AutolayoutPG/VisualFormatLanguage.html
- 对子View进行如下设置:TranslatesAutoresizingMaskIntoConstraints = false;
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 using System; 2 using System.Drawing; 3 4 using CoreGraphics; 5 using Foundation; 6 using MyPassword.Utils; 7 using SaturdayMP.XPlugins.iOS; 8 using UIKit; 9 10 namespace MyPassword.iOS.View.CheckContainer 11 { 12 public partial class CheckBoxContainerUIView : UIView 13 { 14 public CheckBoxContainerUIView() 15 { 16 Initialize(); 17 } 18 19 public CheckBoxContainerUIView(IntPtr handle) : base(handle) 20 { 21 Initialize(); 22 } 23 24 25 public CheckBoxContainerUIView(RectangleF bounds) : base(bounds) 26 { 27 Initialize(); 28 } 29 30 void Initialize() 31 { 32 var checkboxNum = CreateCheckBox(); 33 checkboxNum.On = true; 34 var checkBoxUpper = CreateCheckBox(); 35 checkBoxUpper.On = true; 36 var checkboxSign = CreateCheckBox(); 37 checkboxSign.On = true; 38 var checkBoxLower = CreateCheckBox(); 39 checkBoxLower.On = true; 40 41 42 AddSubview(checkboxNum); 43 AddSubview(checkBoxUpper); 44 AddSubview(checkboxSign); 45 AddSubview(checkBoxLower); 46 47 48 var labelNum = CreateLabel("Numbers"); 49 var labelUpper = CreateLabel("Upper Case"); 50 var labelSign = CreateLabel("Signs"); 51 var labelLower = CreateLabel("Lower Case"); 52 53 54 AddSubview(labelNum); 55 AddSubview(labelUpper); 56 AddSubview(labelSign); 57 AddSubview(labelLower); 58 59 60 var viewsDictionary = NSDictionary.FromObjectsAndKeys( 61 new NSObject[] 62 { 63 checkboxNum, 64 checkBoxUpper, 65 checkboxSign, 66 checkBoxLower, 67 labelNum, 68 labelUpper, 69 labelSign, 70 labelLower 71 }, 72 new NSObject[] 73 { 74 new NSString("checkboxNum"), 75 new NSString("checkBoxUpper") , 76 new NSString("checkboxSign"), 77 new NSString("checkBoxLower"), 78 new NSString("labelNum") , 79 new NSString("labelUpper"), 80 new NSString("labelSign"), 81 new NSString("labelLower") 82 }); 83 var metrics = new NSDictionary(); 84 85 86 int labelWidth = (int)Bounds.Width / 2 - 18 - 2 - 8 - 2; 87 88 AddConstraints(NSLayoutConstraint.FromVisualFormat("H:|-2-[checkboxNum(18)]-(==8)-[labelNum("+ labelWidth + ")]-2-[checkboxSign(18)]-(==8)-[labelSign(" + labelWidth + ")]-2-|", 0, new NSDictionary(), viewsDictionary)); 89 AddConstraints(NSLayoutConstraint.FromVisualFormat("V:|-8-[checkboxNum(18)]-(==8)-[checkBoxUpper(==checkboxNum)]-|", 0, new NSDictionary(), viewsDictionary)); 90 AddConstraints(NSLayoutConstraint.FromVisualFormat("V:|-8-[checkboxSign(18)]-(==8)-[checkBoxLower(==checkboxSign)]-|", 0, new NSDictionary(), viewsDictionary)); 91 AddConstraints(NSLayoutConstraint.FromVisualFormat("H:|-2-[checkBoxUpper(18)]-(==8)-[labelUpper(" + labelWidth + ")]-2-[checkBoxLower(18)]-(==8)-[labelLower(" + labelWidth + ")]-2-|", 0, new NSDictionary(), viewsDictionary)); 92 AddConstraints(NSLayoutConstraint.FromVisualFormat("V:|-8-[labelNum(18)]-(==8)-[labelUpper]-8-|", 0, new NSDictionary(), viewsDictionary)); 93 AddConstraints(NSLayoutConstraint.FromVisualFormat("V:|-8-[labelSign(18)]-(==8)-[labelLower]-8-|", 0, new NSDictionary(), viewsDictionary)); 94 95 } 96 97 private BEMCheckBox CreateCheckBox() 98 { 99 var checkBox = new BEMCheckBox(new CoreGraphics.CGRect(140, 60, 18, 18)) 100 { 101 BoxType = BEMBoxType.Circle, 102 OnAnimationType = BEMAnimationType.Stroke, 103 OffAnimationType = BEMAnimationType.Stroke, 104 OnTintColor = UIColor.Blue, 105 OnCheckColor = UIColor.Blue 106 107 }; 108 checkBox.TranslatesAutoresizingMaskIntoConstraints = false; 109 return checkBox; 110 } 111 112 private UILabel CreateLabel(string content) 113 { 114 var label = new UILabel 115 { 116 Text = content 117 }; 118 int width = (int)Bounds.Width / 2 - 18 - 2 - 8; 119 label.Frame = new RectangleF(2, 200, width, 18); 120 label.TranslatesAutoresizingMaskIntoConstraints = false; 121 return label; 122 } 123 124 private void Checkbox_AnimationDidStopForCheckBox(object sender, EventArgs e) 125 { 126 var checkbox = sender as BEMCheckBox; 127 DebugUtil.WriteLine("Checkbox_AnimationDidStopForCheckBox"); 128 if (checkbox == null) 129 return; 130 DebugUtil.WriteLine(""+checkbox.On); 131 } 132 } 133 }