Be familiar with the general characteristics of the canvas tag

To understand the common attributes of the Canvas tag, specific code examples are required

The Canvas tag is an important element in HTML5 and is used to draw graphics, animations and videos on web pages and other elements. By setting the properties of the Canvas tag and using JavaScript code, you can achieve various cool effects. This article will introduce the common properties of the Canvas tag and give specific code examples to help readers better understand and use these properties.

1. width and height attributes
   The width and height attributes of the Canvas tag are used to set the width and height of the canvas respectively. For example:

<canvas id="myCanvas" width="500" height="300"></canvas>

The above code creates a canvas with a width of 500 pixels and a height of 300 pixels. We can adjust the size of the canvas by modifying the values ​​of these two properties.

2. getContext() method
   The getContext() method is used to obtain the rendering context and drawing environment of the Canvas object. This method accepts a parameter that specifies the type of drawing context. Commonly used types are "2d" and "webgl". For example:

var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");

The above code obtains a 2D drawing context, through which we can perform various drawing operations.

3. fillStyle property
   The fillStyle property is used to set the fill color of the graphic. Colors can be specified using color names, RGB values, hexadecimal values, etc. For example:

ctx.fillStyle = "red";

The above code sets the fill color of the graphic to red.

4. strokeStyle property
   The strokeStyle property is used to set the stroke color of the graphic. Similar to fillStyle, colors can be specified in various ways. For example:

ctx.strokeStyle = "blue";

The above code sets the stroke color of the graphic to blue.

5. lineWidth property
   The lineWidth property is used to set the line width of the brush. For example:

ctx.lineWidth = 2;

The above code sets the brush's line width to 2 pixels.

6. beginPath() and closePath() methods
   beginPath() method is used to start a new path, and closePath() method is used to close the current path. For example:

ctx.beginPath();
ctx.closePath();

The above code starts a new path and closes the current path.

7. moveTO() and lineTo() methods
   The moveTo() method is used to move the drawing starting point to the specified coordinates, and the lineTo() method is used to draw a straight line to the specified coordinates. For example:

ctx.moveTo(100, 100);
ctx.lineTo(200, 200);

The above code will draw a straight line from (100, 100) to (200, 200).

8. arc() method
   arc() method is used to draw an arc or a partial arc. This method accepts 6 parameters, namely the coordinates of the center of the circle, radius, starting angle, ending angle, and whether it is clockwise. For example:

ctx.arc(200, 200, 50, 0, 2 * Math.PI);

The above code will draw a circle with a radius of 50 pixels.

9. fill() and stroke() methods
   The fill() method is used to fill the current path, and the stroke() method is used to draw the stroke of the current path. For example:

ctx.fill();
ctx.stroke();

The above code fills and draws the current path.

Through the above code examples, we can learn about the common attributes and usage of the Canvas tag. By flexibly using these attributes, we can achieve various complex drawing effects and improve the interactivity and visual effects of web pages. Readers can flexibly adjust the values ​​of these attributes according to their specific needs to achieve the effects they want.

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