SemanticValue.ContainsKey(String) 方法

public:
 virtual bool ContainsKey(System::String ^ key);

public bool ContainsKey(string key);

abstract member ContainsKey : string -> bool
override this.ContainsKey : string -> bool

Public Function ContainsKey (key As String) As Boolean

参数

返回

返回 bool、true ，如果以字符串 key 标记的 SemanticValue 子实例被找到， 如果没有，返回 false。

实现

示例

以下示例演示事件的处理程序， SpeechRecognized 该处理程序旨在处理更改前景色和背景色的命令。

处理已识别但没有语义结构的短语后，处理程序使用 ContainsKey (applyChgToBackground、 colorRGBValueList或 colorStringList)检查是否存在适当的键，然后处理语义组织的数据。

newGrammar.SpeechRecognized +=
  delegate(object sender, SpeechRecognizedEventArgs eventArgs)
  {

    // Retrieve the value of the semantic property.
    bool changeBackGround = true;
    string errorString = "";
    SemanticValue semantics = eventArgs.Result.Semantics;

    Color newColor = Color.Empty;

    try
    {
      if (semantics.Count == 0 && semantics.Value==null)
      {

        // Signifies recognition by a grammar with no semantics.
        // Parse the string, assuming that the last word is color,
        // searching for background or foreground in input.
        if (eventArgs.Result.Text.Contains("foreground"))
        {
          changeBackGround = false;
        }
        string cName = eventArgs.Result.Words[eventArgs.Result.Words.Count - 1].Text;
        newColor = Color.FromName(cName);

      }
      else if (semantics.ContainsKey("colorStringList") ^ semantics.ContainsKey("colorRGBValueList"))
      {

        // Determine whether to change background or foreground.
        if (semantics.ContainsKey("applyChgToBackground"))
        {
          changeBackGround = semantics["applyChgToBackground"].Value is bool;
        }

        // Get the RGB color value.
        if (semantics.ContainsKey("colorStringList"))
        {
          newColor = Color.FromName((string)semantics["colorStringList"].Value);
        }
        if (semantics.ContainsKey("colorRGBValueList"))
        {
          newColor = System.Drawing.Color.FromArgb((int)semantics["colorRGBValueList"].Value);
        }
      }
      else
      {

        // Throw an exception if the semantics do not contain the keys we
        // support.
        throw(new Exception("Unsupported semantics keys found."));
      }
    }

    catch (Exception exp)
    {
      MessageBox.Show(String.Format("Unable to process color semantics.:\n{0}\n", exp.Message));
      return;
    }

    // Change colors, either foreground or background.
    if (changeBackGround)
    {
      BackColor = newColor;
      float Bright = BackColor.GetBrightness();
      float Hue = BackColor.GetHue();
      float Sat = BackColor.GetSaturation();
      // Make sure that text is readable regardless of background.
      if (BackColor.GetBrightness() <= .50)
      {
        ForeColor = Color.White;
      }
      else
      {
        ForeColor = Color.Black;
      }
    }
    else
    {
      ForeColor = newColor;
      float Bright = ForeColor.GetBrightness();
      float Hue = ForeColor.GetHue();
      float Sat = ForeColor.GetSaturation();
      // Make sure that text is readable regardless of Foreground.
      if (ForeColor.GetBrightness() <= .50)
      {
        BackColor = Color.White;
      }
      else
      {
        BackColor = Color.Black;
      }
    }
    return;
  };

注解

只能在运行时按键值访问数据，例如检查语义[“myKey”]。值，这会生成异常。 建议先使用 ContainsKey 查询 对象，然后再将 与 给定实例SemanticValue一起使用Item[]。