我有一个带有文本框的自定义用户控件,我想在自定义控件之外公开基线(文本框中的文本)snapline。我知道您创建了一个设计器(继承自ControlDesigner)并覆盖SnapLines以访问snapline,但我想知道如何获取我自定义用户控件公开的控件的文本基线。
答案 0 :(得分:42)
作为Miral答案的更新......这里有一些“缺失的步骤”,对于正在寻找如何做到这一点的新人。 :)上面的C#代码几乎可以“插入”,除了更改一些值以引用将被修改的UserControl。
可能需要参考:
System.Design(@robyaw)
需要使用:
using System.Windows.Forms.Design;
using System.Windows.Forms.Design.Behavior;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Collections;
在UserControl上,您需要以下属性:
[Designer(typeof(MyCustomDesigner))]
然后你需要一个具有SnapLines覆盖的“设计器”类:
private class MyCustomerDesigner : ControlDesigner {
public override IList SnapLines {
get {
/* Code from above */
IList snapLines = base.SnapLines;
// *** This will need to be modified to match your user control
MyControl control = Control as MyControl;
if (control == null) { return snapLines; }
// *** This will need to be modified to match the item in your user control
// This is the control in your UC that you want SnapLines for the entire UC
IDesigner designer = TypeDescriptor.CreateDesigner(
control.textBoxValue, typeof(IDesigner));
if (designer == null) { return snapLines; }
// *** This will need to be modified to match the item in your user control
designer.Initialize(control.textBoxValue);
using (designer)
{
ControlDesigner boxDesigner = designer as ControlDesigner;
if (boxDesigner == null) { return snapLines; }
foreach (SnapLine line in boxDesigner.SnapLines)
{
if (line.SnapLineType == SnapLineType.Baseline)
{
// *** This will need to be modified to match the item in your user control
snapLines.Add(new SnapLine(SnapLineType.Baseline,
line.Offset + control.textBoxValue.Top,
line.Filter, line.Priority));
break;
}
}
}
return snapLines;
}
}
}
}
答案 1 :(得分:25)
我只是有类似的需求,我解决了这个问题:
public override IList SnapLines
{
get
{
IList snapLines = base.SnapLines;
MyControl control = Control as MyControl;
if (control == null) { return snapLines; }
IDesigner designer = TypeDescriptor.CreateDesigner(
control.textBoxValue, typeof(IDesigner));
if (designer == null) { return snapLines; }
designer.Initialize(control.textBoxValue);
using (designer)
{
ControlDesigner boxDesigner = designer as ControlDesigner;
if (boxDesigner == null) { return snapLines; }
foreach (SnapLine line in boxDesigner.SnapLines)
{
if (line.SnapLineType == SnapLineType.Baseline)
{
snapLines.Add(new SnapLine(SnapLineType.Baseline,
line.Offset + control.textBoxValue.Top,
line.Filter, line.Priority));
break;
}
}
}
return snapLines;
}
}
这样它实际上是为子控件创建一个临时子设计器,以便找出“真正的”基线对齐线的位置。
这在测试中看起来相当合理,但如果perf成为一个问题(如果内部文本框没有移动),那么大部分代码都可以提取到Initialize方法。
这也假设文本框是UserControl的直接子代。如果在方式中存在其他影响布局的控件,则偏移计算会变得有点复杂。
答案 2 :(得分:7)
感谢所有人的帮助。这是一个艰难的吞下去。在每个UserControl中都有一个私有子类的想法并不是很可口。
我想出了这个基类来帮助...
[Designer(typeof(UserControlSnapLineDesigner))]
public class UserControlBase : UserControl
{
protected virtual Control SnapLineControl { get { return null; } }
private class UserControlSnapLineDesigner : ControlDesigner
{
public override IList SnapLines
{
get
{
IList snapLines = base.SnapLines;
Control targetControl = (this.Control as UserControlBase).SnapLineControl;
if (targetControl == null)
return snapLines;
using (ControlDesigner controlDesigner = TypeDescriptor.CreateDesigner(targetControl,
typeof(IDesigner)) as ControlDesigner)
{
if (controlDesigner == null)
return snapLines;
controlDesigner.Initialize(targetControl);
foreach (SnapLine line in controlDesigner.SnapLines)
{
if (line.SnapLineType == SnapLineType.Baseline)
{
snapLines.Add(new SnapLine(SnapLineType.Baseline, line.Offset + targetControl.Top,
line.Filter, line.Priority));
break;
}
}
}
return snapLines;
}
}
}
}
接下来,从此基础派生您的UserControl:
public partial class MyControl : UserControlBase
{
protected override Control SnapLineControl
{
get
{
return txtTextBox;
}
}
...
}
再次感谢您发布此内容。
答案 3 :(得分:6)
VB.Net版本:
注意:您必须将txtDescription
更改为文本框或您使用的其他内部控件名称。和ctlUserControl
到usercontrol
名称
<Designer(GetType(ctlUserControl.MyCustomDesigner))> _
Partial Public Class ctlUserControl
'...
'Your Usercontrol class specific code
'...
Class MyCustomDesigner
Inherits ControlDesigner
Public Overloads Overrides ReadOnly Property SnapLines() As IList
Get
' Code from above
Dim lines As IList = MyBase.SnapLines
' *** This will need to be modified to match your user control
Dim control__1 As ctlUserControl = TryCast(Me.Control, ctlUserControl)
If control__1 Is Nothing Then Return lines
' *** This will need to be modified to match the item in your user control
' This is the control in your UC that you want SnapLines for the entire UC
Dim designer As IDesigner = TypeDescriptor.CreateDesigner(control__1.txtDescription, GetType(IDesigner))
If designer Is Nothing Then
Return lines
End If
' *** This will need to be modified to match the item in your user control
designer.Initialize(control__1.txtDescription)
Using designer
Dim boxDesigner As ControlDesigner = TryCast(designer, ControlDesigner)
If boxDesigner Is Nothing Then
Return lines
End If
For Each line As SnapLine In boxDesigner.SnapLines
If line.SnapLineType = SnapLineType.Baseline Then
' *** This will need to be modified to match the item in your user control
lines.Add(New SnapLine(SnapLineType.Baseline, line.Offset + control__1.txtDescription.Top, line.Filter, line.Priority))
Exit For
End If
Next
End Using
Return lines
End Get
End Property
End Class
End Class
答案 4 :(得分:2)
你走在正确的轨道上。您需要覆盖设计器中的SnapLines属性并执行以下操作:
Public Overrides ReadOnly Property SnapLines() As System.Collections.IList
Get
Dim snapLinesList As ArrayList = TryCast(MyBase.SnapLines, ArrayList)
Dim offset As Integer
Dim ctrl As MyControl = TryCast(Me.Control, MyControl)
If ctrl IsNot Nothing AndAlso ctrl.TextBox1 IsNot Nothing Then
offset = ctrl.TextBox1.Bottom - 5
End If
snapLinesList.Add(New SnapLine(SnapLineType.Baseline, offset, SnapLinePriority.Medium))
Return snapLinesList
End Get
End Property
在此示例中,usercontrol包含一个文本框。代码添加了一个新的捕捉线,表示文本框的基线。重要的是正确计算偏移量。