Question

C#单击textbox清空里面文字

做C#窗口程序,需要一个搜索框,里面显示默认文字,然后鼠标点击搜索框后,情况显示的默认文字,如何做才能单击textbox清空里面默认文字

Answer 1

<TextBox Foreground="Indigo" TabIndex="0" BorderThickness="1" Margin="10" Height="20" HorizontalAlignment="Left" Width="150" Grid.Column="0">
<TextBox.Resources>
<VisualBrush x:Key="HelpBrush" TileMode="None" Opacity="0.3" Stretch="None" AlignmentX="Left">
<VisualBrush.Visual>
<TextBlock FontStyle="Italic" Text="文件地址"/>
</VisualBrush.Visual>
</VisualBrush>
</TextBox.Resources>
<TextBox.Style>
<Style TargetType="TextBox">
<Style.Triggers>
<Trigger Property="Text" Value="{x:Null}">
<Setter Property="Background" Value="{StaticResource HelpBrush}"/>
</Trigger>
<Trigger Property="Text" Value="">
<Setter Property="Background" Value="{StaticResource HelpBrush}"/>
</Trigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>

你用wpf试一下。我试过了，绝对可以

Answer 2

选中textbox,在右边的属性窗口里选择“事件”，再双击MouseClick，，写代码。

Answer 3

选中textbox，在属性窗口里选“事件”，再选MouseClick，双击写代码。

Answer 4

Private Sub TextBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown
TextBox1.Text = ""
End Sub

Answer 5

MouseEnter、Enter都可以做到