Question

我正在设置.Text的{{1}}值，禁用它，然后调用textbox来执行冗长的文件系统操作。在BackgroundWorker操作的大约一半之前，文本框不会使用新文本值进行更新。

如何强制texbox尽快显示新文本值？相关代码如下：

BackgroundWorker

更新：我解决了这个问题。这是与此无关的代码 - 我覆盖了void BeginCacheCandidates() { textBox1.Text = "Indexing..."; // <-- this does not update until about 20 to 30 seconds later textBox1.Enabled = false; backgroundWorker1.RunWorkerAsync(); } void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e) { //prime the cache CacheCandidates(candidatesCacheFileName); } void backgroundWorker1_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e) { textBox1.Text = ""; textBox1.Enabled = true; textBox1.Focus(); }并且它已进入循环......

Answer 1

除非我遗漏了一些细节，否则ReportProgress不会给你你想要的东西吗？

void BeginCacheCandidates()
{
    textBox1.Text = "Indexing...";
    textBox1.Enabled = false;
    backgroundWorker1.ReportProgress += new ProgressChangedEventHandler(handleProgress)
    backgroundWorker1.RunWorkerAsync();
}

void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
    //prime the cache
    backgroundWorker1.ReportProgress(<some int>, <text to update>);
    CacheCandidates(candidatesCacheFileName);
}

void handleProgress(object sender, ProgressChangedEventArgs e)
{ 
    ... 
    textBox1.Text = e.UserState as String; 
    ... 
}

Answer 2

尝试在文本框上调用更改，而不是直接调用它。

textBox1.BeginInvoke(new MethodInvoker(() => { textBox1.Text = string.Empty; }));

这将导致在Form的主题上发生更改。

Answer 3

使用Form.Update()方法强制进行UI更新。

void BeginCacheCandidates()
{
    textBox1.Text = "Indexing..."; // <-- this does not update until about 20 to 30 seconds later
    textBox1.Enabled = false;
    this.Update(); // Force update UI
    backgroundWorker1.RunWorkerAsync();
}

尽管使用了BackgroundWorker，UI仍未更新

3 个答案: