Monaco 中 SignatureHelpProvider 是方法提示说明，当敲入方法名时，系统会提示方法名称和对应的参数信息。效果如下：

通过 registerSignatureHelpProvider 实现 SignatureHelpProvider 处理函数。

实现 signatureHelpTriggerCharacters 和 provideSignatureHelp

• signatureHelpTriggerCharacters: 返回触发方法说明的字符列表
• provideSignatureHelp：返回方法信息
  
  返回 SignatureHelpResult
  
  SignatureHelpResult 包含 activeParameter、activeSignature、SignatureInformation[] 三个参数。
  
  SignatureInformation 函数接口信息
  
  ParameterInformation 参数信息
  
  代码实现如下

export function signatureHelpProvider(
  editor: monacoEditor.editor.IStandaloneCodeEditor,
  monaco: typeof monacoEditor
) {
  
  return monaco.languages.registerSignatureHelpProvider("mySpecialLanguage", {
    signatureHelpTriggerCharacters: ['(', ','],
    provideSignatureHelp: function (model, positions, token, context) {
      
      const signature = {
        label: 'add(a: number, b: number): number',
        parameters: [
            {
                label: 'a',
                documentation: 'The first number'
            },
            {
                label: 'b',
                documentation: 'The second number'
            }
            ]
        };

        const result = {
            signatures: [signature],
            activeSignature: 0,
            activeParameter: 0
        };

        return {
            value: result,
            dispose: () => { }
        };
    }
  });
}