有时候需要编辑一些几何图形，如三角形，圆锥曲线等，在UWP应用中加入这些几何作图功能是件费时间又很难做好的事。其实Windows 10 应用商店中已有一些专业的几何作图工具了，那么能借来一用吗？答案是肯定的。
UWP中，微软为Windows.System.Launcher启动器新增了很多的功能，以前只能启动App，打开指定扩展名文件，对uri协议的解析，以及当启动的应用没有安装时则会提示前往商店下载等。
如今，微软丰富了Launcher的功能，通过新增的LaunchUriForResultsAsync API，Windows应用程序可以相互启动并交换数据和文件。利用这个新的API，使得以前需要多个App才能完成的复杂任务现在可以无缝的进行处理，使用户根本无法感觉到应用之间的切换。比如我们可以构想这么一个场景：在一个文本编辑APP中打开一个几何作图APP，完成几何作图后返回几何图片及数据到文本编辑APP。然后点击该图片即可以再次启动几何作图APP编辑几何图形，编辑图形完成后，传递新的图片返回原APP。
首先我们需要从Windows 10 应用商店中安装一个几何作图APP。这里以“活动几何”APP为例，选择它的原因是：1.免费；2.有中文界面；3功能足够。
然后我们就可以上代码了：
Xaml 代码：
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel Margin="20">
<Button x:Name="DoTest" Content="Do test" Click="DoTest_Click" />
<CheckBox x:Name="IsIncludeProcess" Content="IncludeProcess" IsChecked="True" />
<TextBlock x:Name="ShowMessage" Foreground="Red" />
<Button x:Name="DoEdit" Content="Edit the Geometry" Click="DoEdit_Click" Visibility="Collapsed" />
<ScrollViewer Height="600" Width="800" >
<Image x:Name="ShowImage" />
</ScrollViewer>
</StackPanel>
</Grid>
我们的Sample App界面是这样的（为突出重点，省去文本编辑功能代码）：
在“Do test”按钮点击事件函数中：
定义一个LauncherOptions变量，设置属性TargetApplicationPackageFamilyName 为该几何作图APP的PackageFamilyName，这里为62301LeonLi.ActiveGeometry_496e9sjp76zt6 :
var options = new LauncherOptions();
options.TargetApplicationPackageFamilyName = "62301LeonLi.ActiveGeometry_496e9sjp76zt6";
定义一个启动Uri变量:
Uri uri = new Uri("ag.editgeometry:?");
还需要一个传入参数的ValueSet变量 inputData：
ValueSet inputData = new ValueSet();
这样就可以调用LaunchUriForResultsAsync函数启动几何作图APP并将返回结果赋值给LaunchUriResult变量：
LaunchUriResult resultData = await Launcher.LaunchUriForResultsAsync(uri, options, inputData);
启动该几何作图APP后是这样的：
在几何作图完成后，点击返回按钮：
resultData的属性Status 为 LaunchUriStatus.Success 的话，就表示成功了。下面的代码是对返回的结果进行处理:
ValueSet theValues = resultData.Result;
var resultState = theValues["ReturnedState"] as string;
switch (resultState)
{
case "Success":
if (theValues.ContainsKey("ImgFileToken"))
{
var tokenObject = theValues["ImgFileToken"];
if (tokenObject != null)
{
var token = tokenObject.ToString();
var imgFile = await SharedStorageAccessManager.RedeemTokenForFileAsync(token);
if (imgFile != null)
{
try
{
IRandomAccessStream imageStream = await imgFile.OpenReadAsync();
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.SetSource(imageStream);
ShowImage.Source = bitmapImage;
}
finally { }
}
}
}
if (theValues.ContainsKey("DataFileToken"))
{
var tokenObject = theValues["DataFileToken"];
if (tokenObject != null)
{
var token = tokenObject.ToString();
var dataFile = await SharedStorageAccessManager.RedeemTokenForFileAsync(token);
if (dataFile != null)
{
var localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
file_demonstration = await dataFile.CopyAsync(localFolder);
DoEdit.Visibility = Visibility.Visible;
}
}
}
ShowMessage.Text = "Success";
break; }
}
StorageFile file_demonstration;
imgFile是传回的图片文件，可以将该图片插入你想要的地方；dataFile是相应的数据文件，将该文件拷贝到你自己APP的目录下，用文件变量file_demonstration记住它，如果选择了“IsIncludeProcess”，则该文件中还包括了作图过程的数据。现在Sample App是这样的了:
可以看到在得到的几何图上新出现了一个“Edit the Geometry”按钮，这是用于再次编辑该几何图形的:
private async void DoEdit_Click(object sender, RoutedEventArgs e)
{
if (file_demonstration == null)
return;
var token = SharedStorageAccessManager.AddFile(file_demonstration);
ValueSet inputData = new ValueSet();
inputData.Add("EditFileToken", token);
await EditGeometry(true, inputData);
}
完整的代码如下：
namespace CallEditGeometryAppSampleView Code
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
}
private async void DoTest_Click(object sender, RoutedEventArgs e)
{
EditGeometry(true);
}
public async void EditGeometry(bool needResult)
{
bool isNew = true;
ValueSet inputData = new ValueSet();
if (isNew)
{
}
else
{
FileOpenPicker openPicker = new FileOpenPicker();
openPicker.ViewMode = PickerViewMode.List;
openPicker.FileTypeFilter.Add(".sam");
openPicker.FileTypeFilter.Add(".sdz");
var gpxFile = await openPicker.PickSingleFileAsync();
if (gpxFile == null)
{
return;
}
var token = SharedStorageAccessManager.AddFile(gpxFile);
inputData.Add("EditFileToken", token);
}
await EditGeometry(needResult, inputData);
}
private async System.Threading.Tasks.Task EditGeometry(bool needResult, ValueSet inputData)
{
var options = new LauncherOptions();
options.TargetApplicationPackageFamilyName = "62301LeonLi.ActiveGeometry_496e9sjp76zt6";
Uri uri = new Uri("ag.editgeometry:?");
if (!needResult)
{
await Launcher.LaunchUriAsync(uri, options, inputData);
ShowMessage.Text = "No Reuslt Success";
}
else
{
if (!IsIncludeProcess.IsChecked.Value)
{
inputData.Add("IncludeProcess", "N");
}
LaunchUriResult resultData = await Launcher.LaunchUriForResultsAsync(uri, options, inputData);
ShowMessage.Text = resultData.Status.ToString();
if (resultData.Status == LaunchUriStatus.Success &&
resultData.Result != null &&
resultData.Result.ContainsKey("ReturnedState"))
{
ValueSet theValues = resultData.Result;
var resultState = theValues["ReturnedState"] as string;
switch (resultState)
{
case "Success":
if (theValues.ContainsKey("ImgFileToken"))
{
var tokenObject = theValues["ImgFileToken"];
if (tokenObject != null)
{
var token = tokenObject.ToString();
var imgFile = await SharedStorageAccessManager.RedeemTokenForFileAsync(token);
if (imgFile != null)
{
try
{
IRandomAccessStream imageStream = await imgFile.OpenReadAsync();
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.SetSource(imageStream);
ShowImage.Source = bitmapImage;
}
finally { }
}
}
}
if (theValues.ContainsKey("DataFileToken"))
{
var tokenObject = theValues["DataFileToken"];
if (tokenObject != null)
{
var token = tokenObject.ToString();
var dataFile = await SharedStorageAccessManager.RedeemTokenForFileAsync(token);
if (dataFile != null)
{
var localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
file_demonstration = await dataFile.CopyAsync(localFolder);
DoEdit.Visibility = Visibility.Visible;
}
}
}
ShowMessage.Text = "Success";
break;
case "Error":
var resultMessage = theValues["ReturnedMessage"] as string;
if (resultMessage == "Duplicate")
{
string mes = "Active Geometry has opened another windows. Please close it first.";
ShowMessage.Text = mes;
}
var isCloseByOther = theValues["ByOtherClosed"] as string;
if (isCloseByOther != "Y")
{
ShowMessage.Text += " --- By Other Closed";
}
break;
}
}
}
}
StorageFile file_demonstration;
private async void DoEdit_Click(object sender, RoutedEventArgs e)
{
if (file_demonstration == null)
return;
var token = SharedStorageAccessManager.AddFile(file_demonstration);
ValueSet inputData = new ValueSet();
inputData.Add("EditFileToken", token);
await EditGeometry(true, inputData);
}
}
}
如果你连拷贝代码都懒得话，就下载这个sample的压缩文件吧！