tailieunhanh - JavaScript in 10 Simple Steps or Less 2007 phần 9

Tạo hộp mục tiêu xanh, bằng cách sử dụng một thẻ div. Tên dropHere hộp, và hủy bỏ onDragEnter và onDragOver như đã nêu trước đó trong nhiệm vụ này. Cuối cùng, sử dụng onDrop để hiển thị một hộp thoại đặt tên các đối tượng bị kéo lê và nơi mà nó đã bị bỏ | 496 Part 10 Task Changing Page Fonts with a Bookmarklet note This task changes the default font style for the body of the document. If the HTML code for a page has explicit styles used for specific elements of the page that use another font these styles will override the font style specified in the bookmarklet and the bookmarklet will have no effect on those fonts. Sometimes Web pages use hard-to-read fonts. At other times they specify fonts that are missing on your system and your system defaults to a poor alternative. For these cases this task shows how to use a bookmarklet to set the default font style to your preferred font. This task relies on the fact that the document body is represented in the object. This object has a style property containing an object reflecting the style attributes for the body of the document. The fontFamily property of this object can be used to specify a new font by name. For instance to set the default body font of a document to Times you would use the following Times You can also specify a list of fonts just like in a style sheet. The browser will use the first font on the list that it has available Garamond Times SERIF Several generic fonts names are available including SERIF which indicates the default serif font in the browser SANS-SERIF which indicates the default sans serif font in the browser and MONOSPACE which indicates the default fixed-width font in the browser . The following steps show how to build a bookmarklet to set the default font to Arial 1. Open the text editor you normally use for writing JavaScript. 2. Assign Arial to the property Arial 3. Enclose the last command in a void statement otherwise the browser will try to display the font name after assigning it to the document. property and this will cause a page containing just the name of the font to .