ProgressBar.PerformStep 方法

按照 Step 属性的数量增加进度栏的当前位置。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Sub PerformStep
用法
Dim instance As ProgressBar

instance.PerformStep

public void PerformStep ()

public:
void PerformStep ()

public void PerformStep ()

public function PerformStep ()

异常

异常类型	条件
InvalidOperationException	Style 被设置为 Marquee。

备注

PerformStep 方法按照 Step 属性中指定的数量增加进度栏的值。可以使用 Step 属性指定操作中每个完成的任务更改进度栏的值的数量。例如，如果要复制一组文件，则可能需要将 Step 属性的值设置为 1，并将 Maximum 属性的值设置为要复制的文件总数。在复制每个文件时，可以调用 PerformStep 方法按 Step 属性的值增加进度栏。如果想更灵活地控制进度栏的值，则可使用 Increment 方法或直接设置 Value 属性的值。

Value 属性指定 ProgressBar 的当前位置。如果在调用 PerformStep 方法之后，Value 属性大于 Maximum 属性的值，则 Value 属性仍然在 Maximum 属性的值处。在 value 参数中指定负值时调用 PerformStep 方法之后，如果 Value 属性小于 Minimum 属性的值，则 Value 属性仍然在 Minimum 属性的值处。

示例

下面的代码示例使用 ProgressBar 控件来显示文件复制操作的进度。该示例使用 Minimum 和 Maximum 属性指定 ProgressBar 的范围，它等效于要复制的文件数。代码还将 Step 属性用于 PerformStep 方法以在复制文件时增加 ProgressBar 的值。此示例要求已在 Form 中创建了名为 pBar1 的 ProgressBar 控件，并且还创建了执行文件复制操作的名为 CopyFile 的方法（它返回一个布尔值，指示文件复制操作已成功完成）。此段代码还要求已创建包含要复制的文件的字符串数组，并已将其传递给示例中定义的 CopyWithProgress 方法，而且要求从 Form 中的另一个方法或事件中调用该方法。

Private Sub CopyWithProgress(ByVal ParamArray filenames As String())
    ' Display the ProgressBar control.
    pBar1.Visible = True
    ' Set Minimum to 1 to represent the first file being copied.
    pBar1.Minimum = 1
    ' Set Maximum to the total number of files to copy.
    pBar1.Maximum = filenames.Length
    ' Set the initial value of the ProgressBar.
    pBar1.Value = 1
    ' Set the Step property to a value of 1 to represent each file being copied.
    pBar1.Step = 1

    ' Loop through all files to copy.
    Dim x As Integer
    for x = 1 To filenames.Length - 1
        ' Copy the file and increment the ProgressBar if successful.
        If CopyFile(filenames(x - 1)) = True Then
            ' Perform the increment on the ProgressBar.
            pBar1.PerformStep()
        End If
    Next x
End Sub

private void CopyWithProgress(string[] filenames)
{
    // Display the ProgressBar control.
    pBar1.Visible = true;
    // Set Minimum to 1 to represent the first file being copied.
    pBar1.Minimum = 1;
    // Set Maximum to the total number of files to copy.
    pBar1.Maximum = filenames.Length;
    // Set the initial value of the ProgressBar.
    pBar1.Value = 1;
    // Set the Step property to a value of 1 to represent each file being copied.
    pBar1.Step = 1;
    
    // Loop through all files to copy.
    for (int x = 1; x <= filenames.Length; x++)
    {
        // Copy the file and increment the ProgressBar if successful.
        if(CopyFile(filenames[x-1]) == true)
        {
            // Perform the increment on the ProgressBar.
            pBar1.PerformStep();
        }
    }
}

private:
   void CopyWithProgress( array<String^>^filenames )
   {
      // Display the ProgressBar control.
      pBar1->Visible = true;

      // Set Minimum to 1 to represent the first file being copied.
      pBar1->Minimum = 1;

      // Set Maximum to the total number of files to copy.
      pBar1->Maximum = filenames->Length;

      // Set the initial value of the ProgressBar.
      pBar1->Value = 1;

      // Set the Step property to a value of 1 to represent each file being copied.
      pBar1->Step = 1;

      // Loop through all files to copy.
      for ( int x = 1; x <= filenames->Length; x++ )
      {
         // Copy the file and increment the ProgressBar if successful.
         if ( CopyFile( filenames[ x - 1 ] ) == true )
         {
            // Perform the increment on the ProgressBar.
            pBar1->PerformStep();
         }
      }
   }

private void CopyWithProgress(String fileNames[])
{
    // Display the ProgressBar control.
    pBar1.set_Visible(true);
    // Set Minimum to 1 to represent the first file being copied.
    pBar1.set_Minimum(1);
    // Set Maximum to the total number of files to copy.
    pBar1.set_Maximum(fileNames.get_Length());
    // Set the initial value of the ProgressBar.
    pBar1.set_Value(1);
    // Set the Step property to a value of 1 to represent each file
    // being copied.
    pBar1.set_Step(1);
    // Loop through all files to copy.
    for (int x = 1; x <= fileNames.get_Length(); x++) {
        // Copy the file and increment the ProgressBar if successful.
        if (CopyFile(fileNames[(x - 1)]) == true) {
            // Perform the increment on the ProgressBar.
            pBar1.PerformStep();
        }
    }
} //CopyWithProgress

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

ProgressBar 类
ProgressBar 成员
System.Windows.Forms 命名空间
Maximum
Minimum
Step
PerformStep
Value