SemanticValue.ContainsKey(String) 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
指示当前 SemanticValue 实例集合是否包含具有给定的键字符串的子 SemanticValue 实例。
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
- key
- String
包含String 用于标识 SemanticValue 子实例在当前 SemanticValue下的键字符串。
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[]。