日期:2014-05-17 浏览次数:20651 次
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>Query Selector Demo</title> <style type="text/css"> td { border-style: solid; border-width: 1px; font-size: 300%; } td:hover { background-color: cyan; } #hoverResult { color: green; font-size: 200%; } </style> </head> <body> <section> <!-- create a table with a 3 by 3 cell display --> <table id="tb1"> <tr> <td>A1</td> <td>A2</td> <td>A3</td> </tr> <tr> <td>B1</td> <td>B2</td> <td>B3</td> </tr> <tr> <td>C1</td> <td>C2</td> <td>C3</td> </tr> </table> <div>Focus the button, hover over the table cells, and hit Enter to identify them using querySelector('td:hover').</div> <!-- <button type="button" id="findHover" autofocus>Find 'td:hover' target</button> --> <div id="hoverResult"></div> <script type="text/javascript"> //document.getElementById("findHover").onclick = function() { document.getElementById("tb1").onmouseover = function() { // find the table cell currently hovered in the page var hovered = document.querySelector("td:hover"); if (hovered) document.getElementById("hoverResult").innerHTML = hovered.innerHTML; } </script> </section> </body> </html>
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>Simple Canvas Demo</title> </head> <body> <section> <canvas id="diagonal" style="border: 1px solid;" width="200" height="200"> </canvas> <script> function drawDiagonal() { // Get the canvas element and its drawing context var canvas = document.getElementById('diagonal'); var context = canvas.getContext('2d'); // Create a path in absolute coordinates context.beginPath(); context.moveTo(70, 140); context.lineTo(140, 70); // Stroke the line onto the canvas context.stroke(); } window.addEventListener("load", drawDiagonal, true); </script> </section> </body> </html>
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>Draw Trees Demo</title> </head> <body> <section> <canvas id="trails" style="border: 1px solid;" width="500" height="300"> </canvas> <script> function createCanopyPath(context) { // Draw the tree canopy context.beginPath(); context.moveTo(-25, -50); context.lineTo(-10, -80); context.lineTo(-20, -80); context.lineTo(-5, -110); context.lineTo(-15, -110); // Top of the tree context.lineTo(0, -140); context.lineTo(15, -110); context.lineTo(5, -110); context.lineTo(20, -80); context.lineTo(10, -80); context.lineTo(25, -50); // Close the path back to its start point context.closePath(); } function drawTrails(context) { context.save(); context.translate(130, 250); // Create the shape for our canopy path createCanopyPath(context); // Stroke the current path context.stroke(); context.restore(); } var canvas = document.getElementById('trails'); var c2 = canvas.getContext('2d'); window.addEventListener("load", drawTrails(c2), true); </script> </section> </body> </html>