问题 单项选择题

为了在列表框中使用<Ctrl>和<Shift>键进行多个列表项的选择,应将列表框的MultiSelect属性设置为( )。

A.0

B.2

C.False

D.True

答案

参考答案:B

解析: MultiSelect属性运行时只读,返回或设置一个值,用于指示是否能够在控件中进行复选以及如何进行复选。默认值为0,表示不允许复选;值为1时,表示简单复选,即鼠标单击或按下空格键,在列表中选中或取消选中项,用箭头移动焦点;值为2时,表示扩展复选,即按下<Shift>键并单击鼠标或按下<shift>键以及一个箭头键(上箭头、下箭头、左箭头和右箭头),将在以前选中项的基础上扩展选择到当前选中项;按下<Ctrl>键并单击鼠标,在列表中选中或取消选中项。

问答题

Ragtime is a musical form that synthesizes folk melodies and musical techniques into a brief quadrille-like structure, designed to be played—exactly as written—on the piano. (46) A p analogy exists between European composers like Ralph Vaughan Williams and Edward Grieg, who combined folk tunes and their own original materials in larger compositions and the pioneer composers in the United States. Composers like Scott Joplin and James Scott were in a sense collectors or musicologists, collecting dance and folk music in Black communities and consciously shaping it into brief suites or anthologies called piano rags.

It has sometimes been charged that ragtime is mechanical. For instance, Wilfred Mellers comments, "rags were transferred to the pianola roll and, even if not played by a machine, should be played like a machine, with meticulous precision." (47)However, there is no reason to assume that ragtime is inherently mechanical simply because commercial manufacturers applied a mechanical recording method to it, the only way to record pianos at that date. Ragtime’s is not a mechanical precision, and it is not precision limited to the style of performance. It arises from ragtime’s following a well-defined form and obeying simple rules within that form.

The classic formula for the piano rag disposes three to five themes in sixteen-bar strains, often organized with repeats. (48)The rag opens with a bright, memorable strain or theme, followed by a similar theme, leading to a melody of marked lyrical character, with the structure concluded by a lyrical strain that parallels the rhythmic developments of the earlier themes. The aim of the structure is to rise from one theme to another in a stair-step manner, ending on a note of triumph or exhilaration. Typically, each strain is divided into two 8-bar segments that are essentially alike, so the rhythmic-melodic unit of ragtime is only eight bars of 2/4 measure. (49) Therefore, not concerned with development of musical themes, the ragtime composer instead sets a theme down intact, in finished form, and links it to various related themes that are brief with clear melodic figures. Tension in ragtime compositions arises from a polarity between two basic ingredients: a continuous bass—called by jazz musicians a boom-chick bass--in the pianist’s left hand, and its melodic, syncopated counterpart in the right hand.

Ragtime remains distinct from jazz both as an instrumental style and as a genre. Ragtime style stresses a pattern of repeated rhythms, not the constant inventions and variations of jazz. (50)As a genre, ragtime requires strict attention to structure, not inventiveness or virtuosity, existing as a tradition, a set of conventions, a body of written scores, separate from the individual players associated with it. In this sense ragtime is more akin to folk music of the nineteenth century than to jazz.

(48)The rag opens with a bright, memorable strain or theme, followed by a similar theme, leading to a melody of marked lyrical character, with the structure concluded by a lyrical strain that parallels the rhythmic developments of the earlier themes.