继续学习wpf的系列课程.
首先我们看一下后台代码访问前台的UI控件.
这块的知识比较老套,不管我们开发cs,bs都一直在使用的.在讲着系列课程的时候,我以及把所以的代码,要要讲的内容都写了一遍,发博客只是改动一些东西.
<Window x:Class="WPFUserPanel.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="后天获取XAML 元素" Height="395" Width="395" BorderThickness="5" FlowDirection="LeftToRight" Grid.IsSharedSizeScope="False" ShowActivated="False" Background="BlanchedAlmond">
<Window.Resources >
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="121*" />
<ColumnDefinition Width="123*" />
<ColumnDefinition Width="119*" />
</Grid.ColumnDefinitions>
<TextBox Grid.ColumnSpan="3" Margin="27,47,31,78" Name="textBox1" FontSize="24">Hello WPF 太神奇了</TextBox>
<Button Grid.Row="1" Height="48" Margin="105,0,108,0" Name="button1" VerticalAlignment="Top" Click="button1_Click" Background="SandyBrown" BorderThickness="1" FontSize="18" Grid.ColumnSpan="3">第一种方式</Button>
<Button Margin="105,54,108,76" Name="button2" Grid.Row="1" Click="button2_Click" Background="SandyBrown" BorderThickness="1" FontSize="18" Grid.ColumnSpan="3">第二种方式</Button>
<Button Margin="105,0,108,28" Name="button3" Grid.Row="1" Click="button3_Click" Background="SandyBrown" BorderThickness="1" FontSize="18" Grid.ColumnSpan="3" Height="42" VerticalAlignment="Bottom">第三种方式</Button>
</Grid>
</Window>
前台的xaml代码,没什么好说的.
后台代码的几种访问方式.
namespace WPFUserPanel {
public partial class Window1 : Window {
public Window1() {
InitializeComponent();
}
void B_SizeChanged(object sender, SizeChangedEventArgs e) {
throw new NotImplementedException();
}
private void button1_Click(object sender, RoutedEventArgs e) {
//第一种访问的方式,刚我们可以用GetValue的方式来访问,当然你直接textBox1.Text是最简单的
System.Windows.MessageBox.Show("" + this.textBox1.GetValue(TextBox.TextProperty).ToString());
}
private void button2_Click(object sender, RoutedEventArgs e) {
//这个类似于开发bs的FindControl一样,来查找我们需要的控件
TextBox t = this.FindName("textBox1") as TextBox;
System.Windows.MessageBox.Show("第二种方式:" + t.Text);
}
private void button3_Click(object sender, RoutedEventArgs e) {
//这种比较麻烦, 我们先找到内容
var v = this.Content;
//转为grid布局控件,然后把控件全部拷贝到控件数组
Grid g = v as Grid;
UIElementCollection uc = g.Children;
Control[] us = new Control[uc.Count];
g.Children.CopyTo(us, 0);
//用linq来查找这个控件. 相信大家能看懂简单的linq, 我的linq水平也是半吊子.. 一直都是在用linqToObjects,别的也没看,看20分钟 就能简单使用了.
string str = (us.First (a => a.Name == "textBox1") as TextBox).Text;
System.Windows.MessageBox.Show("第三种方式:" + str);
}
}
}
我们接着玩一个纯cs文件的wpf程序,相信大家做cs的时候,经常这样玩,我以前就是,不用窗体,只用代码来写cs程序.
我们来创建一个wpf应用程序,把所有的东西全部删掉.ok,我们把下面的代码添加进去
namespace WPFLayoutDemo
{
class subMain : System.Windows.Application
{
[STAThread]//指定com的线程模型是单线程基元
public static void Main()
{
System.Windows.Application app = new Application();
MyWindow mw = new MyWindow();
mw.Width = 400;
mw.Height = 400;
mw.BorderThickness = new Thickness(50, 5, 50, 5);
app.Run(mw);//启动应用程序
}
}
public partial class MyWindow : Window
{
Canvas canv;
Ellipse e1;
Button b1;
Label lab1;
Rectangle r1;
public MyWindow()
{
canv = new Canvas();
canv.Name = "C1";
this.Content = canv;//让当前的对象等于canvas
canv.Margin = new Thickness(0, 0, 0, 0);
canv.Background = new SolidColorBrush(Colors.White);
e1 = new Ellipse();
e1.Fill = new SolidColorBrush(Colors.YellowGreen);
e1.Stroke = new SolidColorBrush(Colors.Azure);
e1.Width = 200;
e1.Height = 200;
e1.Margin = new Thickness(50, 100, 0, 0);
canv.Children.Add(e1);//让canvas的实例去添加一个元素
r1 = new Rectangle();
r1.Fill = new SolidColorBrush(Colors.Tomato);
r1.Opacity = 0.5;
r1.Stroke = new SolidColorBrush(Colors.Red);
r1.Width = 200;
r1.Height = 200;
r1.SetValue(Canvas.LeftProperty, (double)150);
r1.SetValue(Canvas.TopProperty, (double)100);
canv.Children.Add(r1);
b1 = new Button();
b1.Width = 100;
b1.Height = 20;
b1.Content = "修改圆形位置";
b1.SetValue(Canvas.LeftProperty, (double)r1.GetValue(Canvas.LeftProperty) + 50);
b1.SetValue(Canvas.TopProperty, (double)r1.GetValue(Canvas.TopProperty) + 50);
b1.Click += new RoutedEventHandler(b1_Click);
canv.Children.Add(b1);
Label lab0 = new Label();
lab0.Margin = new Thickness(20, 20, 0, 0);
lab0.Width = 400;
lab0.Height = 40;
lab0.FontSize = 24;
lab0.Name = "lab0";
lab0.Content = "无XAML动态编程演示 作者:常鲲";
canv.Children.Add(lab0);
lab1 = new Label();
lab1.Margin = new Thickness(20, 50, 0, 0);
lab1.Width = 400;
lab1.Height = 40;
lab1.FontSize = 24;
lab1.Name = "lab1";
lab1.Content = "Location:?";
canv.Children.Add(lab1);
//这个是Ellipse的实例对象的MouseMove事件.
e1.MouseMove += new System.Windows.Input.MouseEventHandler(el_MouseMove);
}
void b1_Click(object sender, RoutedEventArgs e)
{
Point p = System.Windows.Input.Mouse.GetPosition(canv as System.Windows.IInputElement);
//重新设置Ellipse的位置,前面讲过两种的设置方法.
e1.Margin = new Thickness(p.X, p.Y, 0, 0);
}
void el_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
Ellipse a = e.Source as Ellipse;
//获得当前鼠标的位置,这个是wpf重新封装的一个类库用System.Windows.Input.Mouse来获得鼠标的各种状态.
Point p = System.Windows.Input.Mouse.GetPosition(canv as
System.Windows.IInputElement);
lab1.Content = "Location:" + p.ToString();//
}
}
}
总体来说,这个小技术,控件查找,动态窗体,以后会用的很多.也比较简单,好理解.
下面我们来学习样式,样式其实和bs的样式表类似,只是写法不同而已.
先来看一下xaml代码.
<Window x:Class="WPF_资源和样式.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="400" Width="400" Loaded="Window_Loaded">
<Window.Resources >//这里我定义了静态资源
// TargetType="{x:Type Button}" 注意这句话 这是为Button设置的样式,别的控件不能使用
<Style x:Key="GreenButtonStyle" TargetType="{x:Type Button}">
//属性样式都是以Setter开头的
<Setter Property="Control.Width" Value="350"/>
<Setter Property="Control.Height" Value="100"/>
<Setter Property="Control.FontSize" Value="24"/>
//事件样式都是以EventSetter开头的 Event是指那种类型的事件 Handler是指向后台的一个方法
<EventSetter Handler="Button_Click" Event="Click"></EventSetter>
</Style>
<SolidColorBrush x:Key="backgroundBrush">Yellow</SolidColorBrush>
<SolidColorBrush x:Key="borderBrush">Red</SolidColorBrush>
</Window.Resources>
<Grid Background="{StaticResource borderBrush}">
//我们只需要用style来指定一下静态资源就可以了
<Button Style="{StaticResource GreenButtonStyle}" Background="{ StaticResource backgroundBrush}">WPF 资源和样式的应用</Button>
<Label Height="53" Margin="31,27,41,0" Name="label1" VerticalAlignment="Top" FontSize="24">WPF 中资源和样式的应用</Label>
//这个button使用的是动态资源,后面就是这个资源的代码
<Button Content="这是通过字典项设置的样式" Margin="17,0,17,73.163" Style="{DynamicResource GreyButton}" VerticalAlignment="Bottom" Height="35.837" />
</Grid>
</Window>
//资源字典的代码
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style x:Key="GreyButton" TargetType="Button" >
<Setter Property="Background" Value="#00FFFF"/>
</Style>
</ResourceDictionary>
//后台的代码
private void Button_Click(object sender, RoutedEventArgs e)
{
global::System.Windows.MessageBox.Show("WPF 的 XAML 确实强大！");
}
我们后台只有一个button的click的事件,总体来说,样式只是写法不同,并没有多少技术难度.
这章我们先认识一些比较麻烦的东西,下章开始讲解.
依赖属性,路由事件,binding,和命令,把这些讲解完毕后,wpf的基础部分就告一段落,剩下的年后再说.