Question

是否可以附加onclick事件以向左，向右和向右移动对象img。

按钮是占位符，顺序是左，右和右。

我面临两个问题： -

1.我的宽度是500px，即使我在250px画了它。它并不居中 2.我尝试了多种方法将onclick功能添加到-/+ y-axis和x-axis @charset "utf-8"; /* Global Styles */ #main { width:100%; background-color:red; } body { margin-left: auto; margin-right: auto; width: 92%; max-width: 960px; padding-left: 2.275%; padding-right: 2.275%; } /* Header */ header { text-align: center; display: block; } header .profileLogo .logoPlaceholder { background-color: white; color:black; width: 300px; text-align: center; } header .logoPlaceholder span { width: 180px; height: 22px; font-family: 'Montserrat', sans-serif; color: black; font-size: 30px; font-weight: 700; line-height: 53px; } header .logoPlaceholder2 span { width: 180px; height: 22px; font-family: 'Montserrat', sans-serif; color: black; font-size: 30px; font-weight: 700; line-height: 53px; } header .profilePhoto { background-color: rgba(237,237,237,1.00); width: 259px; border-radius: 50%; height: 259px; clear: both; } header .profileHeader h1 { font-family: 'Montserrat', sans-serif; color: rgba(146,146,146,1.00); font-size: 30px; font-weight: 700; line-height: 24px; } header .profileHeader h3 { font-family: sans-serif; color: rgba(146,146,146,1.00); font-size: 16px; font-weight: 700; line-height: 24px; } hr { background-color: rgba(208,207,207,1.00); height: 1px; } header .profileHeader p { font-family: sans-serif; color: rgba(146,146,146,1.00); font-size: 14px; font-weight: 400; line-height: 1.8; overflow-y: auto; } header .socialNetworkNavBar { text-align: center; display: block; margin-top: 60px; clear: both; } header .socialNetworkNavBar .socialNetworkNav { border-radius: 50%; cursor: pointer; } header .socialNetworkNavBar .socialNetworkNav img:hover { opacity: 0.5; } /* Media query for Mobile devices*/ @media only screen and (min-width : 285px) and (max-width : 480px) { /* Header */ #main { width:100%; } header { width: 100%; float: left; } .wrapper { display: inline-block; width: 100%; height: 100%; } header .profileLogo .logoPlaceholder { display: inline-block; text-align: left; } header .profilePhoto { display: inline-block; } header .profileHeader { text-align: center; margin-top: 10%; } header .profileHeader p { text-align: justify; } header .socialNetworkNavBar { text-align: center; display: block; margin-top: 60px; clear: both; margin-bottom: 15%; } header .socialNetworkNavBar .socialNetworkNav { width: 60px; height: 60px; display: inline-block; margin-right: 23px; } } /* Media Query for Tablets */ @media only screen and (min-width : 481px) and (max-width : 1024px) { /* Header */ header { width: 100%; float: none; } header .profileLogo .logoPlaceholder { display: inline-block; font-family: 'Montserrat', sans-serif; } header .profilePhoto { float: left; clear: both; margin-right: 3%; margin-top: 5%; } header .profileHeader { text-align: left; margin-top: 7%; } header .socialNetworkNavBar .socialNetworkNav { width: 74px; height: 74px; display: inline-block; margin-right: 23px; } } /* Desktops and laptops */ @media only screen and (min-width:1025px) { /* Header */ header .profileLogo .logoPlaceholder { float: left; margin-bottom: 50px; } header .profilePhoto { float: left; clear: both; margin-right: 3%; } header .profileHeader { text-align: left; padding-top: 10%; } header .socialNetworkNavBar .socialNetworkNav { width: 74px; height: 74px; display: inline-block; margin-right: 23px; } .wrapper { display: table; padding: 0; width: 100%; height: 100%; } .container { display: table-cell; vertical-align: middle; } .canvas-container { position: relative; max-width: 1024px; min-width: 120px; margin: 0 auto; } }。

我甚至试图适应这段代码：
http://www.authorcode.com/how-to-move-an-object-on-the-html5-canvas/

但也没有运气。有什么我想念的吗？我在google上检查过的主要是关键事件处理程序。

JSBIN：

http://jsbin.com/wuseguvuka/2/edit?html,css,output

CSS：

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>About Page template By Adobe Dreamweaver CC</title>
<link href="AboutPageAssets/styles/aboutPageStyle.css" rel="stylesheet" type="text/css">

<!--The following script tag downloads a font from the Adobe Edge Web Fonts server for use within the web page. We recommend that you do not modify it.-->
<script>var __adobewebfontsappname__="dreamweaver"</script><script src="http://use.edgefonts.net/montserrat:n4:default;source-sans-pro:n2:default.js" type="text/javascript"></script>

<script>


function load() {
 var context = document.getElementById('main').getContext("2d");

var img = new Image();
img.src = "http://via.placeholder.com/75x150";
img.onload = function () {

    context.drawImage(img, 250, 0);
}

}
</script>

</head>

<body onload="load();">
<!-- Header content -->
<header>
  <div class="profileLogo"> 
    <!-- Profile logo. Add a img tag in place of <span>. -->
    <p class="logoPlaceholder"><!-- <img src="logoImage.png" alt="sample logo"> --><span>Name :</span></p>
    <p class="logoPlaceholder"><!-- <img src="logoImage.png" alt="sample logo"> --><span>Attempts :</span></p>
    <p class="logoPlaceholder"><!-- <img src="logoImage.png" alt="sample logo"> --><span>Score :</span></p>
  </div>
  <section>
<div class="wrapper">
  <div class="container">
    <div class="canvas-container">

      <canvas id="main" width="500px" height="250px"></canvas>
    </div>
  </div>
</div>
  </section>
  <!-- Links to Social network accounts -->
  <aside class="socialNetworkNavBar">
    <div style="margin-right: 50px;" class="socialNetworkNav"> 
      <!-- Add a Anchor tag with nested img tag here --> 
      <input type="image" src="http://via.placeholder.com/75x75" >

      </div>
    <div id="left" style="margin-right: 50px;" class="socialNetworkNav"> 
      <!-- Add a Anchor tag with nested img tag here --> 
      <input type="image" src="http://via.placeholder.com/75x75" > </div>
    <div id="down" style="margin-right: 50px;" class="socialNetworkNav"> 
      <!-- Add a Anchor tag with nested img tag here --> 
      <input id="right"  type="image" src="http://via.placeholder.com/75x75" >
 </div>

  </aside>
</header>
<!-- content -->

</body>
</html>

HTML：

if (process.env.UNIVERSAL) {
const context = {};
markup = renderToString(
  <Router location={req.url} context={context}>
    <App />
  </Router>,
);

// context.url will contain the URL to redirect to if a <Redirect> was used
if (context.url) {
  return res.redirect(302, context.url);
}

if (context.is404) {
  status = 404;
}

Answer 1

是！

绝对可能。以下是如何实现这一目标......

function load() {
   var context = document.getElementById('main').getContext("2d");
   var left = document.getElementById('left');
   var down = document.getElementById('down');
   var right = document.getElementById('right');
   var imgLoaded = false;
   var posX = 250;
   var posY = 0;
   var snap = 10;

   var img = new Image();
   img.onload = function() {
      imgLoaded = true;
      context.drawImage(img, posX, posY);
   };
   img.src = "http://via.placeholder.com/75x150";

   // left button click
   left.onclick = function() {
      if (!imgLoaded) return;
      posX = posX - snap;
      context.clearRect(0, 0, context.canvas.width, context.canvas.height);
      context.drawImage(img, posX, posY);
   };
	
   // down button click
   down.onclick = function() {
      if (!imgLoaded) return;
      posY = posY + snap;
      context.clearRect(0, 0, context.canvas.width, context.canvas.height);
      context.drawImage(img, posX, posY);
   };
	
   // right button click
   right.onclick = function() {
      if (!imgLoaded) return;
      posX = posX + snap;
      context.clearRect(0, 0, context.canvas.width, context.canvas.height);
      context.drawImage(img, posX, posY);
   };

}

@charset "utf-8";
/* Global Styles */

#main {
    width: 100%;
    background-color: red;
}
body {
    margin-left: auto;
    margin-right: auto;
    width: 92%;
    max-width: 960px;
    padding-left: 2.275%;
    padding-right: 2.275%;
}
/* Header */

header {
    text-align: center;
    display: block;
}
header .profileLogo .logoPlaceholder {
    background-color: white;
    color: black;
    width: 300px;
    text-align: center;
}
header .logoPlaceholder span {
    width: 180px;
    height: 22px;
    font-family: 'Montserrat', sans-serif;
    color: black;
    font-size: 30px;
    font-weight: 700;
    line-height: 53px;
}
header .logoPlaceholder2 span {
    width: 180px;
    height: 22px;
    font-family: 'Montserrat', sans-serif;
    color: black;
    font-size: 30px;
    font-weight: 700;
    line-height: 53px;
}
header .profilePhoto {
    background-color: rgba(237, 237, 237, 1.00);
    width: 259px;
    border-radius: 50%;
    height: 259px;
    clear: both;
}
header .profileHeader h1 {
    font-family: 'Montserrat', sans-serif;
    color: rgba(146, 146, 146, 1.00);
    font-size: 30px;
    font-weight: 700;
    line-height: 24px;
}
header .profileHeader h3 {
    font-family: sans-serif;
    color: rgba(146, 146, 146, 1.00);
    font-size: 16px;
    font-weight: 700;
    line-height: 24px;
}
hr {
    background-color: rgba(208, 207, 207, 1.00);
    height: 1px;
}
header .profileHeader p {
    font-family: sans-serif;
    color: rgba(146, 146, 146, 1.00);
    font-size: 14px;
    font-weight: 400;
    line-height: 1.8;
    overflow-y: auto;
}
header .socialNetworkNavBar {
    text-align: center;
    display: block;
    margin-top: 60px;
    clear: both;
}
header .socialNetworkNavBar .socialNetworkNav {
    border-radius: 50%;
    cursor: pointer;
}
header .socialNetworkNavBar .socialNetworkNav img:hover {
    opacity: 0.5;
}
/* Media query for Mobile devices*/

@media only screen and (min-width: 285px) and (max-width: 480px) {
    /* Header */
    
    #main {
        width: 100%;
    }
    header {
        width: 100%;
        float: left;
    }
    .wrapper {
        display: inline-block;
        width: 100%;
        height: 100%;
    }
    header .profileLogo .logoPlaceholder {
        display: inline-block;
        text-align: left;
    }
    header .profilePhoto {
        display: inline-block;
    }
    header .profileHeader {
        text-align: center;
        margin-top: 10%;
    }
    header .profileHeader p {
        text-align: justify;
    }
    header .socialNetworkNavBar {
        text-align: center;
        display: block;
        margin-top: 60px;
        clear: both;
        margin-bottom: 15%;
    }
    header .socialNetworkNavBar .socialNetworkNav {
        width: 60px;
        height: 60px;
        display: inline-block;
        margin-right: 23px;
    }
}
/* Media Query for Tablets */

@media only screen and (min-width: 481px) and (max-width: 1024px) {
    /* Header */
    
    header {
        width: 100%;
        float: none;
    }
    header .profileLogo .logoPlaceholder {
        display: inline-block;
        font-family: 'Montserrat', sans-serif;
    }
    header .profilePhoto {
        float: left;
        clear: both;
        margin-right: 3%;
        margin-top: 5%;
    }
    header .profileHeader {
        text-align: left;
        margin-top: 7%;
    }
    header .socialNetworkNavBar .socialNetworkNav {
        width: 74px;
        height: 74px;
        display: inline-block;
        margin-right: 23px;
    }
}
/* Desktops and laptops  */

@media only screen and (min-width: 1025px) {
    /* Header */
    
    header .profileLogo .logoPlaceholder {
        float: left;
        margin-bottom: 50px;
    }
    header .profilePhoto {
        float: left;
        clear: both;
        margin-right: 3%;
    }
    header .profileHeader {
        text-align: left;
        padding-top: 10%;
    }
    header .socialNetworkNavBar .socialNetworkNav {
        width: 74px;
        height: 74px;
        display: inline-block;
        margin-right: 23px;
    }
    .wrapper {
        display: table;
        padding: 0;
        width: 100%;
        height: 100%;
    }
    .container {
        display: table-cell;
        vertical-align: middle;
    }
    .canvas-container {
        position: relative;
        max-width: 1024px;
        min-width: 120px;
        margin: 0 auto;
    }
}

<!doctype html>
<html>

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>About Page template By Adobe Dreamweaver CC</title>
    <link href="AboutPageAssets/styles/aboutPageStyle.css" rel="stylesheet" type="text/css">

    <!--The following script tag downloads a font from the Adobe Edge Web Fonts server for use within the web page. We recommend that you do not modify it.-->
    <script>
        var __adobewebfontsappname__ = "dreamweaver"
    </script>
    <script src="http://use.edgefonts.net/montserrat:n4:default;source-sans-pro:n2:default.js" type="text/javascript"></script>

</head>

<body onload="load();">
    <!-- Header content -->
    <header>
        <div class="profileLogo">
            <!-- Profile logo. Add a img tag in place of <span>. -->
            <p class="logoPlaceholder">
                <!-- <img src="logoImage.png" alt="sample logo"> --><span>Name :</span></p>
            <p class="logoPlaceholder">
                <!-- <img src="logoImage.png" alt="sample logo"> --><span>Attempts :</span></p>
            <p class="logoPlaceholder">
                <!-- <img src="logoImage.png" alt="sample logo"> --><span>Score :</span></p>
        </div>
        <section>
            <div class="wrapper">
                <div class="container">
                    <div class="canvas-container">

                        <canvas id="main" width="500px" height="250px"></canvas>
                    </div>
                </div>
            </div>
        </section>
        <!-- Links to Social network accounts -->
        <aside class="socialNetworkNavBar">
            <div id="left" style="margin-right: 50px;" class="socialNetworkNav">
                <!-- Add a Anchor tag with nested img tag here -->
                <input type="image" src="http://via.placeholder.com/75x75">

            </div>
            <div id="down" style="margin-right: 50px;" class="socialNetworkNav">
                <!-- Add a Anchor tag with nested img tag here -->
                <input type="image" src="http://via.placeholder.com/75x75"> </div>
            <div id="right" style="margin-right: 50px;" class="socialNetworkNav">
                <!-- Add a Anchor tag with nested img tag here -->
                <input type="image" src="http://via.placeholder.com/75x75">
            </div>

        </aside>
    </header>
    <!-- content -->

</body>

</html>

^{没有给出解释的道歉}

使用onclick移动HTML移动画布对象

1 个答案: