5.02 WPF的 Combox、ListBox，slider、ProgressBar使用

1. 关于Combox\ListBox使用：

1.1 内容绑定有两种方法，

优先使用方法1，因为列表变化的时候，Combox会自动显示新的内容。而方法2并不会实时更新。

方法1：使用DataContext

 this.comboBox1.DisplayMemberPath = "name";  //显示的内容
 this.comboBox1.SelectedValuePath = "address";   //SelectedValue对应的列
 this.comboBox1.DataContext = m_Person2;

在xml中需要增加如下一句话：ItemsSource="{Binding}"

方法2：使用ItemsSource

 this.comboBox.DisplayMemberPath = "name";
 this.comboBox.SelectedValuePath = "address";
 this.comboBox.ItemsSource = m_Person;

【备注】

1.例子中的name，address必须是 属性字段。至于Person是类或者结构体没有关系。

2.可以通过SelectedItem 得到选择的对象，或者SelectedValue直接得到选择对象中绑定的值。

 private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
 {
     if (this.comboBox1.SelectedIndex > -1)
     {
        var item= (this.comboBox1.SelectedItem) as Person;

         MessageBox.Show(item.address.ToString());

        // MessageBox.Show(this.comboBox.SelectedValue.ToString());
     }
 }

1.2 具体代码：

 public class Person
 {
     public string name { get; set; }
     public string address { get; set; }
 }
 public List<Person> m_Person = new List<Person>();
 public List<Person> m_Person2 = new List<Person>();


m_Person.Add(new Person { name = "mike1", address = "天街1号" });
m_Person.Add(new Person { name = "mike2", address = "天街2号" });
m_Person.Add(new Person { name = "mike3", address = "天街3号" });
m_Person.Add(new Person { name = "mike4", address = "天街4号" });
this.comboBox.DisplayMemberPath = "name";
this.comboBox.SelectedValuePath = "address";
this.comboBox.ItemsSource = m_Person;   //方法1

 m_Person2.Add(new Person { name = "marry1", address = "银河系1号" });
 m_Person2.Add(new Person { name = "marry2", address = "银河系2号" });
 m_Person2.Add(new Person { name = "marry3", address = "银河系3号" });
 m_Person2.Add(new Person { name = "marry4", address = "银河系4号" });
 this.comboBox1.DisplayMemberPath = "name";
 this.comboBox1.SelectedValuePath = "address";
 this.comboBox1.DataContext = m_Person2;  //方法2


 private void button_Click(object sender, RoutedEventArgs e)
 {
     m_Person.Add(new Person { name = "mike5", address = "天街5号" });
     m_Person2.Add(new Person { name = "marry5", address = "银河系5号" });

 }

界面：

 <ComboBox x:Name="comboBox" HorizontalAlignment="Left" Margin="143,149,0,0" VerticalAlignment="Top" Width="120" SelectionChanged="comboBox_SelectionChanged"/>
 <ComboBox x:Name="comboBox1" ItemsSource="{Binding}" HorizontalAlignment="Left" Margin="153,217,0,0" VerticalAlignment="Top" Width="120" SelectionChanged="comboBox1_SelectionChanged"/>

二、Slider

slider比较关键的参数是： 

Minimum="0" Maximum="100" SmallChange="1"  Orientation="Horizontal"  TickPlacement="Both"

注意：对于label要实施显示这个slider的数值，可以用下列办法，即把label绑定到这个slider上。

 Content="{Binding ElementName=slider, Path=Value, Mode=OneWay}"

  <Slider x:Name="slider" HorizontalAlignment="Left" Margin="359,103,0,0" VerticalAlignment="Top" Width="217" RenderTransformOrigin="0.5,0.5" Height="39"
          Minimum="0" Maximum="100" SmallChange="1"  Orientation="Horizontal"  TickPlacement="Both" >

  </Slider>
  <Label x:Name="label" Content="{Binding ElementName=slider, Path=Value, Mode=OneWay}" HorizontalAlignment="Left" Margin="370,142,0,0" VerticalAlignment="Top"/>

三、ProgressBar

比较关键的参数是： 

Minimum="0" Maximum="100"   Orientation="Horizontal" 

另外：IsIndeterminate=true时，进度条将一直在动，含义是加载中。

 <ProgressBar IsIndeterminate="true" Height="10" Minimum="0" Maximum="100" Width="100" Value="40"/>

备注：如果希望按了按钮后，进度条陆续移动，可以用如下方法实现：

private void button1_Click(object sender, RoutedEventArgs e)
{
    int start = (int)this.pbar1.Minimum;
    int end= (int)this.pbar1.Maximum;
    new Task(()=>
    {               
        for (int i = start; i < end; i++)
        {
            this.pbar1.Dispatcher.Invoke(()=> {
                this.pbar1.Value = i;
            });
            Thread.Sleep(100);
        }
    }).Start();      
}