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分享异步更新ui时出现的问题
一个比较简单的例子，点开始变量累加，显示在文本框，取消后停止，但是当我再点开始提示不能对已完成的任务调用start，代码如下
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qbilbo 2016-02-17
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cts = new CancellationTokenSource();
Task t = new Task(() => Add(cts.Token), cts.Token);
t.Start();
liujiahaol12345 2016-02-17
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public partial class Form1 : Form
{
int num = 0;
CancellationTokenSource cts = new CancellationTokenSource();
public Form1()
{
InitializeComponent();
}
private void btnStart_Click(object sender, EventArgs e)
{
Task t = new Task(() => Add(cts.Token), cts.Token);
t.Start();
}
public void Add(CancellationToken cts)
{
while (!cts.IsCancellationRequested)
{
num++;
if (this.InvokeRequired)
{
txt1.Invoke(new Action(() => txt1.Text = num.ToString()));
}
else
txt1.Text = num.ToString();
}
}
private void btnStop_Click(object sender, EventArgs e)
{
cts.Cancel();
}
}
{
int num = 0;
CancellationTokenSource cts = new CancellationTokenSource();
public Form1()
{
InitializeComponent();
}
private void btnStart_Click(object sender, EventArgs e)
{
Task t = new Task(() => Add(cts.Token), cts.Token);
t.Start();
}
public void Add(CancellationToken cts)
{
while (!cts.IsCancellationRequested)
{
num++;
if (this.InvokeRequired)
{
txt1.Invoke(new Action(() => txt1.Text = num.ToString()));
}
else
txt1.Text = num.ToString();
}
}
private void btnStop_Click(object sender, EventArgs e)
{
cts.Cancel();
}
}
