WPF中ToolTip的自定义

ToolTip或者PopUp这个控件在做界面时会经常用到。如何对ToolTip进行自定义呢？

1.首先自定义tooltip的controlTemplate，完全清除系统默认效果， 如下：

            <ControlTemplate x:Key ="TooltipTemplate" TargetType="ToolTip">

                <ContentPresenter x :Name="contentPresenter" Height="{TemplateBinding Height }" Width="{ TemplateBinding Width}" ContentTemplate="{TemplateBinding ContentTemplate }" ></ContentPresenter>

            </ControlTemplate>

2.自定义tooltip的contentTemplate， 这样可以专注于tooltip的界面呈现， 而不关心tooltip要显示的字符串， 如下：

                <Style x :Key="ToolTipStyle" TargetType="ToolTip">

                     <Setter Property ="IsOpen" Value="False">

                </Setter>

               

                <Setter Property ="ContentTemplate">

                    <Setter.Value>

                        <DataTemplate>

                            <Border x :Name="errorBorder" Background="#CC595959" BorderBrush="#99000000" BorderThickness="1" CornerRadius ="3" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin ="0" MaxWidth="320">

                                <Border.Effect>

                                    <DropShadowEffect BlurRadius ="4" ShadowDepth="0"/>

                                </Border.Effect>

                                <Grid>

                                    <Grid.ColumnDefinitions>

                                        <ColumnDefinition Width ="Auto"/>

                                        <ColumnDefinition Width ="*"/>

                                    </Grid.ColumnDefinitions>

                                    <Border Margin ="16,16,8,16" VerticalAlignment="Top">

                                        <Path x :Name="path1" Grid.ColumnSpan="1" Data="M9.0789473,12.870737 L10.927632,12.870737 10.927632,14.5 9.0789473,14.5 z M9.0000001,5.9999999 L11,5.9999999 11,7.994543 10.526316,12.308322 9.4802633,12.308322 9.0000001,7.994543 z M9.9647158,1.8074455 C9.5912184,1.7923756 9.2860216,2.1402843 9.2860216,2.1402845 9.2860216,2.1402843 2.5977592,14.8926 2.2227221,15.46075 1.8476844,16.028899 2.5562553,16.218284 2.5562553,16.218284 2.5562553,16.218284 16.2035,16.218284 17.18278,16.218284 18.162063,16.218284 17.870029,15.460751 17.870029,15.460751 17.870029,15.460751 11.056506,2.8352754 10.494117,2.1197443 10.31837,1.8961406 10.134488,1.8142953 9.9647158,1.8074455 z M9.9331295,0.00021409988 C10.317457,0.0076069832 10.762559,0.20740509 11.244278,0.77299643 12.785778,2.5828881 19.97391,16.249695 19.97391,16.249695 19.97391,16.249695 20.318179,17.954408 18.505573,17.985971 16.692966,18.017535 1.5982747,17.985971 1.5982747,17.985971 1.5982747,17.985971 -0.27740097,18.206807 0.03512764,16.028899 0.3476572,13.850991 8.5362361,0.89893103 8.536236,0.8989315 8.5362361,0.89893103 9.0876089,-0.016049385 9.9331295,0.00021409988 z" Height="17" Stretch="Fill" Width="20" Visibility="Visible" Fill ="Red"/>

                                    </Border>

                                    <TextBlock x :Name="textBlock" Text="{TemplateBinding Content }" Margin="0,14,10,14" FontSize="14" Grid.Column ="1" TextWrapping="Wrap" Foreground="Red"/>

                                </Grid>

                            </Border>

                        </DataTemplate>

                    </Setter.Value>

                </Setter>

                <Style.Triggers>

                    <Trigger Property ="IsOpen" Value="True">

                        <Trigger.EnterActions>

                            <BeginStoryboard>

                                <Storyboard>

                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Duration="0:0:3">

                                        <DiscreteObjectKeyFrame KeyTime ="0:0:0">

                                            <DiscreteObjectKeyFrame.Value>

                                                <Visibility> Visible</Visibility >

                                            </DiscreteObjectKeyFrame.Value>

                                        </DiscreteObjectKeyFrame>

                                        <DiscreteObjectKeyFrame KeyTime ="0:0:3">

                                           <DiscreteObjectKeyFrame.Value>

                                                <Visibility> Hidden</Visibility >

                                           </DiscreteObjectKeyFrame.Value>

                                        </DiscreteObjectKeyFrame>

                                    </ObjectAnimationUsingKeyFrames>

                                </Storyboard>

                            </BeginStoryboard>

                        </Trigger.EnterActions>

                    </Trigger>

                </Style.Triggers>

            </Style>

3.应用Tooltip的style，如下：

     <Button Content ="TestButton">

            < Button.ToolTip>

                < ToolTip Style ="{ DynamicResource ToolTipStyle}" Content="This is a button"></ ToolTip >

            </ Button.ToolTip>

        </ Button>

4.以上style使用时的注意事项：

因为Animation的设置值优先于本地设置值，所以会出现ToolTip在动画结束时永远隐藏。

因此在需要打开tooltip时，首先要在动画开始时设置Visibility为Visible，第二要触发IsOpen=True则必须先IsOpen=False， 因为在Tooltip隐藏后并没有设置IsOpen=False。

代码如下：

                        _toolTip.Style = ToolTipStyle;

                        _toolTip.PlacementTarget = this.AssociatedObject;

                        _toolTip.Placement = PlacementMode.Bottom;

                        _toolTip.Content = toolTipText;

                        //must set false first to trigger storyboard

                        _toolTip.IsOpen = false;

                        _toolTip.IsOpen = true;

                        _toolTip.StaysOpen = false;

5.ToolTip的bug

对于ToolTip的显示延迟、显示时间长度、是否保持显示、显示时的位置等等，通用的做法都是通过ToolTipService来进行统一设置。比如：

      ToolTipService.InitialShowDelay="1000"
      ToolTipService.ShowDuration="7000"
      ToolTipService.BetweenShowDelay="2000"
      ToolTipService.Placement="Right" 
      ToolTipService.PlacementRectangle="50,0,0,0"
      ToolTipService.HorizontalOffset="10" 
      ToolTipService.VerticalOffset="20"
      ToolTipService.HasDropShadow="false"
      ToolTipService.ShowOnDisabled="true" 
      ToolTipService.IsEnabled="true"

但是，我发现在TextBox的PreviewInput事件里去弹出tooltip时， 以上的ToolTipService设置并没有起到效果，Tooltip的弹出位置和显示时间还是默认的， 即跟随鼠标显示，默认5s。

这个时候就需要对ToolTip的相关属性进行设置。

 _toolTip.Style = ToolTipStyle;

            _toolTip.PlacementTarget = this.AssociatedObject;

            _toolTip.Placement = PlacementMode.Bottom;

当然，当我们toolTip和ToolTipService都设置相关属性时， ToolTipService的设置优先。