標籤內容和進度條

Question

創建Windows窗體應用程序，並添加進度條顯示的加載文件的進度，以及標籤上方的進度條顯示每個文件，但總和路徑很長的路徑，並顯示在行，但我的寬格式對於小一些的路徑不會出現所有的，我看到在堆棧溢出和谷歌不止一個解決方案，但確實爲使汽車大小虛假，碼頭填不實用，並改變size.I想路徑長度的方法動態變化。

Answer 1

爲了讓整個路徑出現（例如換行），您需要將Label的Height設置爲某個值，比如50。因此，它可能會像Label與50一個Height和300一個Width，然後是下方的ProgressBar。

而且，看來你的問題是，你在主線程上執行長時間運行的操作。這就是爲什麼Label不刷新。您需要使用BackgroundWorker。因此，添加一個類變量是：

private BackgroundWorker _worker = new BackgroundWorker(); 

然後在ctor做到這一點：

_worker.WorkerReportsProgress = true; 
_worker.DoWork += DoBackgroundWork; 
_worker.ProgressChanged += ReportProgress; 

，然後這些處理程序：

private void DoBackgroundWork(object sender, DoWorkEventArgs e) 
{ 
    // do the work you're doing in here -but add the below line when you want 
    // to update the text of your label 
    _worker.ReportProgress(1, "Your label text here"); 
} 

private void ReportProgress(object sender, ProgressChangedEventArgs e) 
{ 
    this.label.Text = e.UserState as string; 
} 

---

的最後一件事你可能要考慮，那就是切斷字符串到關閉到您的標籤的長度，而不是試圖使其包裝。下面是一組證明這種可能的解決方案的方法。

有一點要注意的是，截止程序利用了倉搜索，所以它不是難以置信準確。我的意思是什麼？那麼，假設您有一個長度爲150個字符的字符串（如下例所示），並且第一次將它切成兩半並測量字符串。如果寬度小於最大寬度（例如在Label的寬度），它只是將返回字符串。這很有效，但標籤長度上可能存在空間並且可能會截斷較少的字符。

爲了使這個更準確，你將不得不作出更多的傳球，以及國際海事組織，這只是沒有足夠重要的是要枚舉的通行證。使用System.ComponentModel

public partial class Form1 : Form 
{ 
    string[] chars = new string[] 
    { 
     "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", 
     "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z" 
    }; 

    public Form1() 
    { 
     InitializeComponent(); 
    } 

    private void button1_Click(object sender, EventArgs e) 
    { 
     var filePath = BuildString(150); 
     var g = this.label1.CreateGraphics(); 
     var size = g.MeasureString(filePath, this.Font); 
     var oneCharacterLen = (size.Width/(float)filePath.Length); 
     if (size.Width > ((float)this.label1.Width - (oneCharacterLen * 3f))) 
     { 
      this.label1.Text = CutoffStringBinSearch(g, string.Format("{0}", filePath), 0, this.label1.Width); 
     } 
    } 

    private string CutoffStringBinSearch(Graphics g, string s, int startIndex, int maxWidth) 
    { 
     var midPoint = (s.Length - startIndex)/2; 
     var subString = string.Format("{0}...", s.Substring(startIndex, midPoint)); 

     var len = g.MeasureString(subString, this.Font); 
     if (len.Width > (float)maxWidth) { return CutoffStringBinSearch(g, s.Substring(startIndex, midPoint), 0, maxWidth); } 

     return subString; 
    } 

    private string BuildString(int len) 
    { 
     string[] s = new string[len]; 
     var random = new Random(0); 
     for (int i = 0; i < len; i++) 
     { 
      s[i] = chars[random.Next(0, chars.Length - 1)]; 
     } 
     return string.Join("", s); 
    } 
} 

Answer 2

using System; 

;使用System.Windows.Forms的 ;

命名空間BackgroundWorkerSimple { 公共部分Form1類：形式 { 公共Form1中（） { 的InitializeComponent（）; backgroundWorker1.WorkerReportsProgress = true; backgroundWorker1。WorkerSupportsCancellation = true; }

private void startAsyncButton_Click(object sender, EventArgs e) 
    { 
     if (backgroundWorker1.IsBusy != true) 
     { 
      // Start the asynchronous operation. 
      backgroundWorker1.RunWorkerAsync(); 
     } 
    } 

    private void cancelAsyncButton_Click(object sender, EventArgs e) 
    { 
     if (backgroundWorker1.WorkerSupportsCancellation == true) 
     { 
      // Cancel the asynchronous operation. 
      backgroundWorker1.CancelAsync(); 
     } 
    } 

    // This event handler is where the time-consuming work is done. 
    private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
    { 
     BackgroundWorker worker = sender as BackgroundWorker; 

     for (int i = 1; i <= 10; i++) 
     { 
      if (worker.CancellationPending == true) 
      { 
       e.Cancel = true; 
       break; 
      } 
      else 
      { 
       // Perform a time consuming operation and report progress. 
       System.Threading.Thread.Sleep(500); 
       worker.ReportProgress(i * 10); 
      } 
     } 
    } 

    // This event handler updates the progress. 
    private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) 
    { 
     resultLabel.Text = (e.ProgressPercentage.ToString() + "%"); 
    } 

    // This event handler deals with the results of the background operation. 
    private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 
    { 
     if (e.Cancelled == true) 
     { 
      resultLabel.Text = "Canceled!"; 
     } 
     else if (e.Error != null) 
     { 
      resultLabel.Text = "Error: " + e.Error.Message; 
     } 
     else 
     { 
      resultLabel.Text = "Done!"; 
     } 
    } 
} 

}