试图让多个chart.js图表​​加载在同一页面

Question

由于某种原因，我无法弄清楚如何让多个chart.js图表​​加载到同一页面上。我可以得到一个加载得很好，但是当我添加更多时，他们都没有加载。任何想法，我做错了什么？

<div class="game-cards col-lg-5"> 
     <div class="chart-container"> 
      <canvas id="myChart" width="500" height="500"></canvas> 
     </div> 

     <div class="right-info"> 
      <h4>Iowa State vs Iowa</h4> 
      <h5 id="time-channel">11:00 AM - Channel Goes here</h5> 
      <div class="total-points-live"> 
       <h5>Total Points Bet</h5> 
       <h5 id="point-total">20,000</h5> 
       <p class="bet-button">Click To Place Bet</p> 
      </div> 
     </div> 
     <div> 
      <input class="bet-input" type="text" name="betAmount" placeholder="Wager Amount"> 
     </div> 
    </div> 
    <div class="game-cards col-lg-5"> 
     <div class="chart-container"> 
      <canvas id="myChart" width="500" height="500"></canvas> 
     </div> 

     <div class="right-info"> 
      <h4>Iowa State vs Iowa</h4> 
      <h5 id="time-channel">11:00 AM - Channel Goes here</h5> 
      <div class="total-points-live"> 
       <h5>Total Points Bet</h5> 
       <h5 id="point-total">20,000</h5> 
       <p class="bet-button">Click To Place Bet</p> 
      </div> 
     </div> 
     <div> 
      <input class="bet-input" type="text" name="betAmount" placeholder="Wager Amount"> 
     </div> 
    </div> 

这是JavaScript

window.onload = function() { 
     var ctx = document.getElementById("myChart").getContext('2d'); 

     var myChart = new Chart(ctx, { 
      type: 'doughnut', 
      data: { 
      labels: ["Iowa", "Iowa State"], 
      datasets: [{ 
       backgroundColor: [ 
       "#CC0000", 
       "#F1BE48", 
       ], 
       data: [2000, 9000] 
      }] 
      }, 
      options: { 
       responsive: true 
      , maintainAspectRatio: false 
      } 
     }); 
    } 

Answer 1

你需要交换机ID与类或使独特的IDS

也许使用id="myChart"为先，和id="myChart2"为第二，但你需要创建另一个函数来定位第二个图表。

你可以用类切换ID并通过Javascript将它们定位，如果两个图表共享相同的选项。

var ctx = document.getElementsByClassName("myChart").getContext('2d'); 

Answer 2

不要对多个元素使用相同的ID。 ID必须是唯一！

在你的榜样，将其更改为不同的ID - 也许firstChart和secondChart：

window.onload = function() { 
 
    var ctx = document.getElementById("firstChart").getContext('2d'); 
 

 
    var firstChart = new Chart(ctx, { 
 
    type: 'doughnut', 
 
    data: { 
 
     labels: ["Iowa", "Iowa State"], 
 
     datasets: [{ 
 
     backgroundColor: [ 
 
      "#CC0000", 
 
      "#F1BE48", 
 
     ], 
 
     data: [2000, 9000] 
 
     }] 
 
    }, 
 
    options: { 
 
     responsive: true, 
 
     maintainAspectRatio: false 
 
    } 
 
    }); 
 

 
    var ctx2 = document.getElementById("secondChart").getContext('2d'); 
 

 
    var secondChart = new Chart(ctx2, { 
 
    type: 'doughnut', 
 
    data: { 
 
     labels: ["Iowa", "Iowa State"], 
 
     datasets: [{ 
 
     backgroundColor: [ 
 
      "#CC0000", 
 
      "#F1BE48", 
 
     ], 
 
     data: [2000, 9000] 
 
     }] 
 
    }, 
 
    options: { 
 
     responsive: true, 
 
     maintainAspectRatio: false 
 
    } 
 
    }); 
 
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.0/Chart.bundle.min.js"></script> 
 
<div class="game-cards col-lg-5"> 
 
    <div class="chart-container"> 
 
    <canvas id="firstChart" width="500" height="500"></canvas> 
 
    </div> 
 

 
    <div class="right-info"> 
 
    <h4>Iowa State vs Iowa</h4> 
 
    <h5 id="time-channel">11:00 AM - Channel Goes here</h5> 
 
    <div class="total-points-live"> 
 
     <h5>Total Points Bet</h5> 
 
     <h5 id="point-total">20,000</h5> 
 
     <p class="bet-button">Click To Place Bet</p> 
 
    </div> 
 
    </div> 
 
    <div> 
 
    <input class="bet-input" type="text" name="betAmount" placeholder="Wager Amount"> 
 
    </div> 
 
</div> 
 
<div class="game-cards col-lg-5"> 
 
    <div class="chart-container"> 
 
    <canvas id="secondChart" width="500" height="500"></canvas> 
 
    </div> 
 

 
    <div class="right-info"> 
 
    <h4>Iowa State vs Iowa</h4> 
 
    <h5 id="time-channel">11:00 AM - Channel Goes here</h5> 
 
    <div class="total-points-live"> 
 
     <h5>Total Points Bet</h5> 
 
     <h5 id="point-total">20,000</h5> 
 
     <p class="bet-button">Click To Place Bet</p> 
 
    </div> 
 
    </div> 
 
    <div> 
 
    <input class="bet-input" type="text" name="betAmount" placeholder="Wager Amount"> 
 
    </div> 
 
</div>

或者 - 如果你是因为你不并不需要每个图表参考想以后更改他们 - 使用相同的类的所有图表：

window.onload = function() { 
 
    var charts = document.getElementsByClassName("piechart"); 
 

 
    for (chart of charts) { 
 
    var ctx = chart.getContext('2d'); 
 

 
    new Chart(ctx, { 
 
     type: 'doughnut', 
 
     data: { 
 
     labels: ["Iowa", "Iowa State"], 
 
     datasets: [{ 
 
      backgroundColor: [ 
 
      "#CC0000", 
 
      "#F1BE48", 
 
      ], 
 
      data: [2000, 9000] 
 
     }] 
 
     }, 
 
     options: { 
 
     responsive: true, 
 
     maintainAspectRatio: false 
 
     } 
 
    }); 
 
    } 
 
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.0/Chart.bundle.min.js"></script> 
 
<div class="game-cards col-lg-5"> 
 
    <div class="chart-container"> 
 
    <canvas id="firstChart" class="piechart" width="500" height="500"></canvas> 
 
    </div> 
 

 
    <div class="right-info"> 
 
    <h4>Iowa State vs Iowa</h4> 
 
    <h5 id="time-channel">11:00 AM - Channel Goes here</h5> 
 
    <div class="total-points-live"> 
 
     <h5>Total Points Bet</h5> 
 
     <h5 id="point-total">20,000</h5> 
 
     <p class="bet-button">Click To Place Bet</p> 
 
    </div> 
 
    </div> 
 
    <div> 
 
    <input class="bet-input" type="text" name="betAmount" placeholder="Wager Amount"> 
 
    </div> 
 
</div> 
 
<div class="game-cards col-lg-5"> 
 
    <div class="chart-container"> 
 
    <canvas id="secondChart" class="piechart" width="500" height="500"></canvas> 
 
    </div> 
 

 
    <div class="right-info"> 
 
    <h4>Iowa State vs Iowa</h4> 
 
    <h5 id="time-channel">11:00 AM - Channel Goes here</h5> 
 
    <div class="total-points-live"> 
 
     <h5>Total Points Bet</h5> 
 
     <h5 id="point-total">20,000</h5> 
 
     <p class="bet-button">Click To Place Bet</p> 
 
    </div> 
 
    </div> 
 
    <div> 
 
    <input class="bet-input" type="text" name="betAmount" placeholder="Wager Amount"> 
 
    </div> 
 
</div>