<!DOCTYPE html><html> <head></title> border: 1px gestrichelt grau; } </style> <script type="text/javascript"> if (oCanvas.getContext) { // Den 2D-Zeichnungskontext abrufen var oContext = oCanvas.getContext("2d"); var oImageData = oContext.createImageData(100, 100); var data = oImageData.data; 0 ; i < data.length; i += 4) { // rote Daten[i + 1] = 0; // blaue Daten[i + 2] = 0 ; // Transparenzdaten[i + 3] = 100; } oContext.putImageData(oImageData, 10, 10); </head> <canvas> ="600" width="600"></canvas> </body></html>
为什么会没有效果，我照着课程一起写的