自定义绘制柱形图

时间:2022-04-25
本文章向大家介绍自定义绘制柱形图，主要内容包括设计思路:、2.画竖线和文字、3.画顶部横线、使用方法、完整代码、基本概念、基础应用、原理机制和需要注意的事项等，并结合实例形式分析了其使用技巧，希望通过本文能帮助到大家理解应用这部分内容。

设计思路:

1.画柱状图  2.画竖线  3.画顶部横线  4.画文字

1.画柱状图

画柱状图的方法很简单，就是使用canvas.drawRect(float left, float top, float right, float bottom, Paint paint)，其实这里我遇到了一个问题，一开始我想只画一条柱状图，然后需要几个柱状图就在xml文件中声明几个，后来我发现，这样实现起来的动画非常之卡顿（上面gif录出来看上去很卡，其实很流畅）。后来我就换了一种思路，就是声明一个数组，在Activity传入我们需要画的柱状图的总个数和每个柱状图的目标值大小，然后在onDraw方法里分别计算每个柱状图的当前进度，然后分别画出来，这样动画效果就非常流畅了。

<code class="language-java hljs  has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
         * 画柱状图
         */</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> ; i<totalBarNum ; i++){
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (currentBarProgress[i]<(respTarget.get(i)/max)*stopX) {
                currentBarProgress[i]+=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>;
                postInvalidateDelayed(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>);
            }
            canvas.drawText(respName.get(i),startX,startY+deltaY+i*(deltaY+barWidth)+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>*barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>, mTextPaint);
            canvas.drawRect(startX+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>*barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>, startY+deltaY+i*(deltaY+barWidth), currentBarProgress[i], startY+deltaY+i*(deltaY+barWidth)+barWidth, mBarPaint);
        }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

2.画竖线和文字

有了上面画柱状图的思路，画竖线就非常容易想了，和画柱状图是一个思路，也是Activity中传入需要画几条竖线，然后在onDraw方法里分别去计算他们的当前进度值，然后再分别去画

文字大小应该随着柱形图宽度来自动适应，所以我进行了一些计算，看上去很复杂，其实就是为了自适应文字的大小

<code class="language-java hljs  has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
         * 画竖线
         */</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> ; i<verticalLineNum ; i++){
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (currentVerticalLineProgress< measuredHeight) {
                currentVerticalLineProgress+=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>;
                postInvalidateDelayed(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>);
            }
            canvas.drawLine((startX+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>*barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)+(i+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)*deltaX, startY, (startX+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>*barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)+(i+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)*deltaX, currentVerticalLineProgress, mLinePaint);
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//画文字</span>
            canvas.drawText(numPerUnit*(i+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)+unit, (startX+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>*barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>)+(i+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>)*deltaX-barWidth, startY-barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>, mTextPaint);
        }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>

3.画顶部横线

顶部横线我是从右向左画的，正好与柱状图形成一个对比

<code class="language-java hljs  has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
         * 画最上面的横线
         */</span>
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (currentHorizentalLineProgress>startX+<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>*barWidth/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>) {
            currentHorizentalLineProgress-=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>;
            postInvalidateDelayed(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>);
        }
        canvas.drawLine(stopX, startY, currentHorizentalLineProgress, startY, mLinePaint);
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

使用方法

1.设置柱状图的最大值

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mBarGraph<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.setMax</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">40</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

2.设置柱状图单位

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mBarGraph<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.setUnit</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"亿元"</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

3.设置柱状图宽度

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mBarGraph<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.setBarWidth</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">50</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

4.设置竖线条数

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mBarGraph<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.setVerticalLineNum</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

5.设置柱状图总个数

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> mBarGraph<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.setTotalBarNum</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

6.设置每个柱状图的目标值

<code class="hljs r has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> private ArrayList<Float> respectTarget;
 <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">...</span>
 respectTarget = new ArrayList<Float>();
 respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">35.</span>0f);
        respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20.</span>0f);
        respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18.</span>0f);
        respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15.</span>0f);
        respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10.</span>0f);
        respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.</span>0f);
        respectTarget.add(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5.</span>0f);
  mBarGraph.setRespectTargetNum(respectTarget);</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

7.设置每个柱状图的名字

<code class="hljs r has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">private ArrayList<String> respName;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">...</span>
respName = new ArrayList<String>();
 respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"滴滴"</span>);
        respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"小米"</span>);
        respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"京东"</span>);
        respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"美团"</span>);
        respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"魅族"</span>);
        respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"酷派"</span>);
        respName.add(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"携程"</span>);
mBarGraph.setRespectName(respName);</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

完整代码

大家可以上我的GitHub上下载完整代码

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