使用异步/等待时，WPF进度用法 [英] WPF ProgressBar usage when using Async/Await

问题描述

我加载像这样一些数据的非常简单的任务：

 异步任务<名单<发票>> GetInvoices（）
 {
 VAR发票=等待Task.Run（（）=> db.Invoices.AsNoTracking（）了ToList（））; 
返回发票; 
} 
  

什么是与一个进度使用的最佳方法？我不需要得到的百分比加载（尽管这将是有益的），我只需要显示/隐藏在启动和加载数据的完成进度条。有没有一种方法或许创建完成或结束的方法？

我很新的异步/等待这么心慈手软，请！

< DIV CLASS =h2_lin>解决方案

假设 GetInvoices 被调用一些UI事件处理程序，并有一些所谓的进度条控件进度，这是很简单的：

 专用异步无效OnButton1Click（..）
 {
 ProgressBar.IsIndeterminate = TRUE; 
 VAR的结果=等待GetInvoices（）; 
 ProgressBar.IsIndeterminate = FALSE; //也许隐藏它，太
 // TODO：做的东西有结果
} 
  

如果你想显示实际进展情况，看一看的 进度< T> 和的 IProgress< T>

I have a very simple task that loads some data like so:

async Task<List<Invoice>> GetInvoices()
{
    var invoices = await Task.Run(() => db.Invoices.AsNoTracking().ToList());
    return invoices;
}

What would be the best way to use this with a progressbar? I don't need to get the percentage loaded (although that would be useful), I simply need to show/hide the progressbar at start and finish of loading data. Is there a way to create a completed or finished method perhaps?

I am very new to async/await so kid gloves please!

解决方案

Assuming GetInvoices gets called in some UI event handler and there is some progress bar control called ProgressBar, it's really simple:

private async void OnButton1Click(..)
{
    ProgressBar.IsIndeterminate = true;
    var result = await GetInvoices();
    ProgressBar.IsIndeterminate = false; // Maybe hide it, too
    // TODO: Do stuff with result
}

If you want to show actual progress, take a look at Progress<T> and IProgress<T>.

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