Android:使用canvas绘柱状统计图(自动计算宽高及分度值、可左右滑动)

来源:互联网 发布:黑魂34g内存优化 编辑:程序博客网 时间:2024/05/17 05:13

本例实现了一个简单的柱状统计图,如下:

        

特点:

1.根据数据源自动计算每个条目的高度、宽度、间距,自动计算分度值。

2.当条目数较多时,可左右滑动查看全部内容,图形、文字同步滑动,并且松手后会渐渐的停下来(而不是立刻停下来)。


代码:

(1)核心代码:BarChartView.java

package com.sina.appbarchart;import android.app.Activity;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.graphics.Rect;import android.support.annotation.NonNull;import android.support.v7.app.ActionBar;import android.support.v7.app.ActionBarActivity;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;/** * 自定义组件:条形统计图 * Created by hanj on 14-12-30. */public class BarChartView extends View {    private int screenW, screenH;    private BarChartItemBean[] mItems;    //max value in mItems.    private float maxValue;    //max height of the bar    private int maxHeight;    private int[] mBarColors = new int[]{Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW, Color.MAGENTA, Color.CYAN};    private Paint barPaint, linePaint, textPaint;    private Rect barRect, leftWhiteRect, rightWhiteRect;    private Path textPath;    private int leftMargin, topMargin, smallMargin;    //the width of one bar item    private int barItemWidth;    //the spacing between two bar items.    private int barSpace;    //the width of the line.    private int lineStrokeWidth;    /**     * The x-position of y-index and the y-position of the x-index..     */    private float x_index_startY, y_index_startX;    private Bitmap arrowBmp;    private Rect x_index_arrowRect, y_index_arrowRect;    private static final int BG_COLOR = Color.parseColor("#E5E5E5");    public BarChartView(Context context, AttributeSet attrs) {        super(context, attrs);        init(context);    }    private void init(Context context) {        screenW = ScreenUtils.getScreenW(context);        screenH = ScreenUtils.getScreenH(context);        leftMargin = ScreenUtils.dp2px(context, 16);        topMargin = ScreenUtils.dp2px(context, 40);        smallMargin = ScreenUtils.dp2px(context, 6);        barPaint = new Paint();        barPaint.setColor(mBarColors[0]);        linePaint = new Paint();        lineStrokeWidth = ScreenUtils.dp2px(context, 1);        linePaint.setStrokeWidth(lineStrokeWidth);        textPaint = new Paint();        textPaint.setAntiAlias(true);        barRect = new Rect(0, 0, 0, 0);        textPath = new Path();        leftWhiteRect = new Rect(0, 0, 0, screenH);        rightWhiteRect = new Rect(screenW - leftMargin, 0, screenW, screenH);        arrowBmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.arrow_up);    }    //标记是否已经获取过状态拉的高度    private boolean statusHeightHasGet;    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (!statusHeightHasGet) {            subStatusBarHeight();            statusHeightHasGet = true;        }        //draw background        canvas.drawColor(BG_COLOR);        //bounds        checkLeftMoving();        textPaint.setTextSize(ScreenUtils.dp2px(getContext(), 16));        for (int i = 0; i < mItems.length; i++) {            //draw bar rect            barRect.left = (int) y_index_startX + barItemWidth * i + barSpace * (i + 1) - (int) leftMoving;            barRect.top = topMargin * 2 + (int) (maxHeight * (1.0f - mItems[i].itemValue / maxValue));            barRect.right = barRect.left + barItemWidth;            barPaint.setColor(mBarColors[i % mBarColors.length]);            canvas.drawRect(barRect, barPaint);            //draw type text            String typeText = mItems[i].itemType;            float textPathStartX = barRect.left + barItemWidth / 2 -                    (float) (Math.sin(Math.PI / 6)) * textPaint.measureText("好") / 2;            float textPathStartY = barRect.bottom;            textPath.reset();            textPath.moveTo(textPathStartX, textPathStartY);            textPath.lineTo(textPathStartX + (float) (1000 * Math.tan(Math.PI / 6)), textPathStartY + 1000);            canvas.drawTextOnPath(typeText, textPath, smallMargin * 1.5f, smallMargin * 2, textPaint);            //draw value text            String valueText = String.valueOf(mItems[i].itemValue);            canvas.drawText(valueText, barRect.left - (textPaint.measureText(valueText) - barItemWidth) / 2,                    barRect.top - smallMargin, textPaint);        }        //draw left white space and right white space        int c = barPaint.getColor();        barPaint.setColor(BG_COLOR);        leftWhiteRect.right = (int) y_index_startX;        canvas.drawRect(leftWhiteRect, barPaint);        canvas.drawRect(rightWhiteRect, barPaint);        barPaint.setColor(c);        //draw x-index line.        canvas.drawLine(                y_index_startX - lineStrokeWidth / 2,                x_index_startY,                screenW - leftMargin,                x_index_startY,                linePaint);        //draw y-index line.        canvas.drawLine(                y_index_startX,                x_index_startY + lineStrokeWidth / 2,                y_index_startX,                topMargin / 2,                linePaint);        canvas.drawBitmap(arrowBmp, null, y_index_arrowRect, null);        canvas.save();        canvas.rotate(90, (x_index_arrowRect.left + x_index_arrowRect.right) / 2, (x_index_arrowRect.top + x_index_arrowRect.bottom) / 2);        canvas.drawBitmap(arrowBmp, null, x_index_arrowRect, null);        canvas.restore();        //draw division value        int maxDivisionValueHeight = (int) (maxHeight * 1.0f / maxValue * maxDivisionValue);        textPaint.setTextSize(ScreenUtils.dp2px(getContext(), 10));        for (int i = 1; i <= 10; i++) {            float startY = barRect.bottom - maxDivisionValueHeight * 0.1f * i;            if (startY < topMargin / 2) {                break;            }            canvas.drawLine(y_index_startX, startY, y_index_startX + 10, startY, linePaint);            String text = String.valueOf(maxDivisionValue * 0.1f * i);            canvas.drawText(text,                    y_index_startX - textPaint.measureText(text) - 5,                    startY + textPaint.measureText("0") / 2,                    textPaint);        }    }    private float leftMoving;    private float lastPointX;    private float movingLeftThisTime = 0.0f;    @Override    public boolean onTouchEvent(@NonNull MotionEvent event) {        int type = event.getAction();        switch (type) {            case MotionEvent.ACTION_DOWN:                lastPointX = event.getRawX();                break;            case MotionEvent.ACTION_MOVE:                float x = event.getRawX();                movingLeftThisTime = lastPointX - x;                leftMoving += movingLeftThisTime;                lastPointX = x;                invalidate();                break;            case MotionEvent.ACTION_UP:                //smooth scroll                new Thread(new SmoothScrollThread(movingLeftThisTime)).start();                break;            default:                return super.onTouchEvent(event);        }        return true;    }    /**     * Check the value of leftMoving to ensure that the view is not out of the screen.     */    private void checkLeftMoving() {        if (leftMoving < 0) {            leftMoving = 0;        }        if (leftMoving > (maxRight - minRight)) {            leftMoving = maxRight - minRight;        }    }    public BarChartItemBean[] getItems() {        return mItems;    }    public void setItems(BarChartItemBean[] items) {        if (items == null) {            throw new RuntimeException("BarChartView.setItems(): the param items cannot be null.");        }        if (items.length == 0) {            return;        }        this.mItems = items;        //Calculate the max value.        maxValue = items[0].itemValue;        for (BarChartItemBean bean : items) {            if (bean.itemValue > maxValue) {                maxValue = bean.itemValue;            }        }        //Calculate the max division value.        getRange(maxValue, 0);        //Get the width of each bar.        getBarItemWidth(screenW, items.length);        //Refresh the view.        invalidate();    }    private int maxRight, minRight;    /**     * Get the width of each bar which is depended on the screenW and item count.     */    private void getBarItemWidth(int screenW, int itemCount) {        //The min width of the bar is 50dp.        int minBarWidth = ScreenUtils.dp2px(getContext(), 40);        //The min width of spacing.        int minBarSpacing = ScreenUtils.dp2px(getContext(), 30);        barItemWidth = (screenW - leftMargin * 2) / (itemCount + 3);        barSpace = (screenW - leftMargin * 2 - barItemWidth * itemCount) / (itemCount + 1);        if (barItemWidth < minBarWidth || barSpace < minBarSpacing) {            barItemWidth = minBarWidth;            barSpace = minBarSpacing;        }        maxRight = (int) y_index_startX + lineStrokeWidth + (barSpace + barItemWidth) * mItems.length;        minRight = screenW - leftMargin - barSpace;    }    /**     * Sub the height of status bar and action bar to get the accurate height of screen.     */    private void subStatusBarHeight() {        //The height of the status bar        int statusHeight = ScreenUtils.getStatusBarHeight((Activity) getContext());        //The height of the actionBar        ActionBar ab = ((ActionBarActivity) getContext()).getSupportActionBar();        int abHeight = ab == null ? 0 : ab.getHeight();        screenH -= (statusHeight + abHeight);        barRect.top = topMargin * 2;        barRect.bottom = screenH - topMargin * 3;        maxHeight = barRect.bottom - barRect.top;        x_index_startY = barRect.bottom;        x_index_arrowRect = new Rect(screenW - leftMargin, (int) (x_index_startY - 10),                screenW - leftMargin + 10, (int) (x_index_startY + 10));    }    //The max and min division value.    private float maxDivisionValue, minDivisionValue;    //Get the max and min division value by the max and min value in mItems.    private void getRange(float maxValue, float minValue) {        //max        int scale = Utility.getScale(maxValue);        float unscaledValue = (float) (maxValue / Math.pow(10, scale));        maxDivisionValue = (float) (getRangeTop(unscaledValue) * Math.pow(10, scale));        y_index_startX = getDivisionTextMaxWidth(maxDivisionValue) + 10;        y_index_arrowRect = new Rect((int) (y_index_startX - 5), topMargin / 2 - 20,                (int) (y_index_startX + 5), topMargin / 2);    }    private float getRangeTop(float value) {        //value: [1,10)        if (value < 1.2) {            return 1.2f;        }        if (value < 1.5) {            return 1.5f;        }        if (value < 2.0) {            return 2.0f;        }        if (value < 3.0) {            return 3.0f;        }        if (value < 4.0) {            return 4.0f;        }        if (value < 5.0) {            return 5.0f;        }        if (value < 6.0) {            return 6.0f;        }        if (value < 8.0) {            return 8.0f;        }        return 10.0f;    }    /**     * Get the max width of the division value text.     */    private float getDivisionTextMaxWidth(float maxDivisionValue) {        Paint textPaint = new Paint();        textPaint.setTextSize(ScreenUtils.dp2px(getContext(), 10));        float max = textPaint.measureText(String.valueOf(maxDivisionValue * 0.1f));        for (int i = 2; i <= 10; i++) {            float w = textPaint.measureText(String.valueOf(maxDivisionValue * 0.1f * i));            if (w > max) {                max = w;            }        }        return max;    }    /**     * Use this thread to create a smooth scroll after ACTION_UP.     */    private class SmoothScrollThread implements Runnable {        float lastMoving;        boolean scrolling = true;        private SmoothScrollThread(float lastMoving) {            this.lastMoving = lastMoving;            scrolling = true;        }        @Override        public void run() {            while (scrolling) {                long start = System.currentTimeMillis();                lastMoving = (int) (0.9f * lastMoving);                leftMoving += lastMoving;                checkLeftMoving();                postInvalidate();                if (Math.abs(lastMoving) < 5) {                    scrolling = false;                }                long end = System.currentTimeMillis();                if (end - start < 20) {                    try {                        Thread.sleep(20 - (end - start));                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }        }    }    /**     * A model class to keep the bar item info.     */    static class BarChartItemBean {        private String itemType;        private float itemValue;        public BarChartItemBean(String itemType, float itemValue) {            this.itemType = itemType;            this.itemValue = itemValue;        }    }}
(2)该自定义组件的使用:

package com.sina.appbarchart;import android.support.v7.app.ActionBarActivity;import android.os.Bundle;public class MainActivity extends ActionBarActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        BarChartView barChartView = (BarChartView) findViewById(R.id.bar_chart);        BarChartView.BarChartItemBean[] items = new BarChartView.BarChartItemBean[]{                new BarChartView.BarChartItemBean("餐饮", 300),                new BarChartView.BarChartItemBean("学习", 200),                new BarChartView.BarChartItemBean("旅行", 270),                new BarChartView.BarChartItemBean("购物", 110),                new BarChartView.BarChartItemBean("人际关系", 120),                new BarChartView.BarChartItemBean("娱乐", 80),                new BarChartView.BarChartItemBean("投资", 110),                new BarChartView.BarChartItemBean("教育", 280)        };        barChartView.setItems(items);    }}

================

源码下载(免积分哦!):

http://download.csdn.net/detail/books1958/8386035



2 0