在“ OnApplyTemplate”中检测设计模式。方法-自定义控件 [英] Detect design mode in "OnApplyTemplate" method - custom control

问题描述

这是我的 OnApplyTemplate 的外观：

public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();

            if (DesignerProperties.IsInDesignTool) return;

            this.partTextBox = this.GetTemplateChild(PartTextBox) as TextBox;
            this.partButton = this.GetTemplateChild(PartButton) as Button;

            if (this.partTextBox == null || this.partButton == null)
            {
                throw new NullReferenceException("Template part(s) not available");
            }

            this.partTextBox.LostFocus += this.OnTextBoxLostFocus;
            this.partButton.Click += this.OnButtonClick;

            if (this.DataProvider == null)
            {
                throw new NotSupportedException("DataProvider wasn't specified");
            }

我检查IsInDesignTool的第二行错误提示我不能

Second line where I check for IsInDesignTool gives me error saying that I can't access internal class "DesignerProperties" here.

基本上，当我将控件从工具栏拖到设计视图中时，会发生异常，因为未指定DataProvider会引发异常。因此，我需要在设计时间上禁用此代码。

Basically what happens is when I drag my control from toolbar into view in design it throws exception because DataProvider not specified. So, I need to disable this code for desing time.

我该怎么做？

推荐答案

也许某个地方存在另一个称为DesignerProperties的类，它正在干扰您真正想要使用的类。怎么样：

Maybe there's another class somewhere called DesignerProperties which is interfering with the one you really want to use. How about:

if (System.ComponentModel.DesignerProperties.IsInDesignTool) return;

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