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自定义view—折线图

学习导航

第一节:http://blog.csdn.net/bobo8945510/article/details/53197727 —自定义View—自定义属性及引用

第二节:http://blog.csdn.net/bobo8945510/article/details/53203233 自定义view02—图形绘制

第三节:http://blog.csdn.net/bobo8945510/article/details/53213938 自定义View-绘图基础之Path

第四节:http://blog.csdn.net/bobo8945510/article/details/53256863 Android实现手写板和涂鸦

第五节:http://blog.csdn.net/bobo8945510/article/details/53257232 环形进度条


绘制折线图预览图

技术分享


绘制这个折线图需要都需要哪些步骤?


一、如何绘制X和Y轴。

注意:绘制线用到的是path,而绘制X和Y轴,我们需要知道三个坐标,这里我们用的是 canvas.drawPath(mPath,linePaint);

技术分享

1、我们来分析下,我们想知道三个坐标,那么这三个坐标是多少呢,我们该怎么计算呢?

答:这里,我是在onSizeChanged()方法中获取到了父类控件的宽度,然后把宽度分成16份,例如,下方的上下左右四个分别如下:

         lift = viewSize*(1/16f);
         top = viewSize*(1/16f);
         right = viewSize*(15/16f);
         buttom = viewSize*(8/16f);

2、这三个坐标我们有了,那就好办了,我们根据这四个参数值,就可以知道我们上面三个坐标点的坐标,在draw()方法中,连接这三个点即可:

  private void drawXY(Canvas canvas) {
        /*
        * 第三步,我们来通过viewSize尺寸来获取三个坐标点
        * 第一个(X,Y)--(lift,top)
        * 第二个(X,Y)--(lift,button)
        * 第三个个(X,Y)--(right,buttom)
        * */
        mPath.moveTo(lift, top);
        mPath.lineTo(lift, buttom);
        mPath.lineTo(right,buttom);

        //使用Path链接这三个坐标
        canvas.drawPath(mPath,linePaint);

        // 释放画布
        canvas.restore();
    }

3、我们最后,在X,Y轴写个文字,那么我们需要知道X,Y这两个文字的坐标是多少?如图:

技术分享

答:因为我们已经知道lift,right,top, buttom。其实我们就可计算出来他们的坐标了。其实Y轴的坐标只是向右移动一点即可(lift+num,top),x的坐标向下移动一点即可(right,top+num),其中num是你移动多少。自己可以合理调试

private void drawXYelement(Canvas canvas) {
        // 锁定画布
        canvas.save();
        mTextPaint.setTextSize(36);//文字大小

        /*
        * Y轴文字提示
        * drawText(String ,x,y,TextPaint)
        * (lift,top)
        * */
        mTextPaint.setTextAlign(Paint.Align.LEFT);//左对齐
        canvas.drawText("Y",lift+20,top,mTextPaint);


        /*
        * X轴文字提示
        * drawText(String ,right,buttom,TextPaint)
        * */
        mTextPaint.setTextAlign(Paint.Align.RIGHT);//右对齐
        canvas.drawText("X",right,buttom+50,mTextPaint);
        // 释放画布
        canvas.restore();
    }

我们在main的xml引用此类

    <tester.ermu.com.polylinedemo.XYView01
        android:id="@+id/My_XYView04"
        android:layout_width="wrap_content"
        android:layout_height="500dp"
        android:background="#8B7500"
       />

编译一下效果:

技术分享

4、附上全部代码

package tester.ermu.com.polylinedemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;


/**
 * Created by ENZ on 2016/11/25.
 * 绘制自定义view折线图
 * 第一步:绘制X和Y轴,那么我们需要什么准备呢?
 */

public class XYView01 extends View {

    private int viewSize;//获取空间的尺寸,也就是我们布局的尺寸大小(不知道理解的是否正确)
    private Paint linePaint;// 线条画笔和点画笔

    private Path mPath;// 路径对象
    private TextPaint mTextPaint;// 文字画笔

    float lift ;
    float top ;
    float right ;
    float buttom ;


    float PathY_X ;
    float PathY_Y ;

    float PathX_X ;
    float PathX_Y ;

    public XYView01(Context context, AttributeSet attrs) {
        super(context, attrs);
        //第一步,初始化对象
        linePaint = new Paint();
        linePaint.setColor(Color.YELLOW);//线条的颜色
        linePaint.setStrokeWidth(8);//线条的宽度
        linePaint.setAntiAlias(true);//取消锯齿
        linePaint.setStyle(Paint.Style.STROKE);//粗线


        //初始化Path
        mPath = new Path();

        mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG | Paint.LINEAR_TEXT_FLAG);
        mTextPaint.setColor(Color.WHITE);
    }

    public XYView01(Context context) {
        super(context);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // 在我们没学习测量控件之前强制宽高一致
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    }
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        //第二步骤,我们在这里获取每个用到的坐标点和尺寸

        viewSize = w;//获取空间的尺寸,
        Log.i("Text","viewSize:"+viewSize);

        //这个是我们上下左右需要用到的坐标点
         lift = viewSize*(1/16f);
         top = viewSize*(1/16f);
         right = viewSize*(15/16f);
         buttom = viewSize*(8/16f);


    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 锁定画布
        canvas.save();
        //定义一个绘制X,Y轴的方法
        drawXY(canvas);

        //绘制X和Y轴上的提示文字
        drawXYelement(canvas);

    }

    private void drawXY(Canvas canvas) {
        /*
        * 第三步,我们来通过viewSize尺寸来获取三个坐标点
        * 第一个(X,Y)--(lift,top)
        * 第二个(X,Y)--(lift,button)
        * 第三个个(X,Y)--(right,buttom)
        * */
        mPath.moveTo(lift, top);
        mPath.lineTo(lift, buttom);
        mPath.lineTo(right,buttom);

        //使用Path链接这三个坐标
        canvas.drawPath(mPath,linePaint);

        // 释放画布
        canvas.restore();
    }

    private void drawXYelement(Canvas canvas) {
        // 锁定画布
        canvas.save();
        mTextPaint.setTextSize(36);//文字大小

        /*
        * Y轴文字提示
        * drawText(String ,x,y,TextPaint)
        * (lift,top)
        * */
        mTextPaint.setTextAlign(Paint.Align.LEFT);//左对齐
        canvas.drawText("Y",lift+20,top,mTextPaint);


        /*
        * X轴文字提示
        * drawText(String ,right,buttom,TextPaint)
        * */
        mTextPaint.setTextAlign(Paint.Align.RIGHT);//右对齐
        canvas.drawText("X",right,buttom+50,mTextPaint);
        // 释放画布
        canvas.restore();
    }
}

二、绘制我们内部的网格,那么如何绘制?

技术分享

1、我们绘制X和Y轴区域的子网格,我们需要知道他们范围?

        Y轴上的最大范围=(buttom - top) ;
        X轴的最大范围=(right - lift) ;       

技术分享

2、在这个范围我们需要分为多少个端即有几个数据?每一段间距事是多少?


        // 假如我们有八条数据
        int count = pointFs.size();

        // 计算横纵坐标刻度间隔
        spaceY =(buttom - top) / count;
        spaceX =(right - lift) / count;

3、最大值和最小值是多少?

 // 计算横轴数据最大值
        maxX = 0;
        for (int i = 0; i < count; i++) {
            if (maxX < pointFs.get(i).x) {
                maxX = pointFs.get(i).x;//X轴最大坐标

            }
        }
        Log.i("Text","maxX:--"+maxX);
        // 计算横轴最近的能被count整除的值
        int remainderX = ((int) maxX) % divisor;
        maxX = remainderX == 0 ? ((int) maxX) : divisor - remainderX + ((int) maxX);


        // 计算纵轴数据最大值
        maxY = 0;
        for (int i = 0; i < count; i++) {
            if (maxY < pointFs.get(i).y) {
                maxY = pointFs.get(i).y;
            }
        }
        Log.i("Text","maxY:--"+maxY);
        // 计算纵轴最近的能被count整除的值
        int remainderY = ((int) maxY) % divisor;
        Log.i("Text","remainderY:--"+remainderY);

4、既然我们已经知道了最大值和最小值,也知道了间距,那么我么开始绘制,通过for循环来绘制Y轴,每绘制每一个Y轴的点,都会把X轴与之相交的点全部绘制。(自己可以在本子上画画图就容易理解了)例如下图

技术分享

    // 锁定画布并设置画布透明度为75%
        int sc = canvas.saveLayerAlpha(0, 0, canvas.getWidth(), canvas.getHeight(), 75, Canvas.ALL_SAVE_FLAG);

        // 绘制横纵线段
        for (float y = buttom - spaceY; y >  top; y -= spaceY) {
            Log.i("Text","y"+y);

            for (float x =  lift; x < right; x += spaceX) {
                Log.i("Text","x"+x);
                /*
                 * 绘制纵向线段
                 */
                if (y == top + spaceY) {
                    canvas.drawLine(x, y, x, y + spaceY * (count - 1), linePaint);
                }

                /*
                 * 绘制横向线段
                 */
                if (x == right - spaceX) {
                    canvas.drawLine(x, y, x - spaceX * (count - 1), y, linePaint);
                }
            }
        }

5、全部代码,只是多了一个方法drawLines(canvas);

package tester.ermu.com.polylinedemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PointF;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;


/**
 * Created by ENZ on 2016/11/25.
 * 绘制自定义view折线图
 * 第一步:绘制X和Y轴,那么我们需要什么准备呢?
 */

public class XYView02 extends View {

    private int viewSize;//获取空间的尺寸,也就是我们布局的尺寸大小(不知道理解的是否正确)
    private Paint linePaint;// 线条画笔和点画笔

    private Path mPath;// 路径对象
    private TextPaint mTextPaint;// 文字画笔

    private List<PointF> pointFs = new ArrayList<>();// 数据列表
    private float[] rulerX, rulerY;// xy轴向刻度

    //上下左右坐标点
    private float lift ;
    private  float top ;
    private  float right ;
    private float buttom ;

    //Y轴文字坐标点
    private float PathY_X ;
    private float PathY_Y ;
    //X轴文字坐标点
    private float PathX_X ;
    private float PathX_Y ;

    private float maxX;//x轴最大值
    private float maxY;//Y轴最大值

    private float spaceX, spaceY;// 刻度间隔

    public XYView02(Context context, AttributeSet attrs) {
        super(context, attrs);
        //第一步,初始化对象
        linePaint = new Paint();
        linePaint.setColor(Color.YELLOW);//线条的颜色
        linePaint.setStrokeWidth(8);//线条的宽度
        linePaint.setAntiAlias(true);//取消锯齿
        linePaint.setStyle(Paint.Style.STROKE);//粗线


        //初始化Path
        mPath = new Path();

        mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG | Paint.LINEAR_TEXT_FLAG);
        mTextPaint.setColor(Color.WHITE);

        //模拟数据
        initData();
    }

    public XYView02(Context context) {
        super(context);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // 在我们没学习测量控件之前强制宽高一致
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    }
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        //第二步骤,我们在这里获取每个用到的坐标点和尺寸

        viewSize = w;//获取空间的尺寸,
        Log.i("Text","viewSize:"+viewSize);

        //这个是我们上下左右需要用到的坐标点
         lift = viewSize*(1/16f);
         top = viewSize*(1/16f);
         right = viewSize*(15/16f);
         buttom = viewSize*(8/16f);

        //下面是绘制X,Y轴提示文字
        /*
        * Y轴(PathY_X,PathY_Y)
        * */
         PathY_X =  viewSize*2/16;
         PathY_Y =  viewSize*1/16;

        /*
        * X轴(PathX_X,PathX_Y)
        * */
        PathX_X =  viewSize*15/16f;
        PathX_Y =  viewSize*9/16f;

    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 锁定画布
        canvas.save();


        //定义一个绘制X,Y轴的方法
        drawXY(canvas);


        //绘制X和Y轴上的提示文字
        drawXYelement(canvas);


    }
    private void initData() {
        Random random = new Random();
        pointFs = new ArrayList<PointF>();
        for (int i = 0; i < 8; i++) {
            PointF pointF = new PointF();

            pointF.x = (float) (random.nextInt(100) * i);
            pointF.y = (float) (random.nextInt(100) * i);

            pointFs.add(pointF);
        }
    }
    private void drawXY(Canvas canvas) {
        /*
        * 第三步,我们来通过viewSize尺寸来获取三个坐标点
        * 第一个(X,Y)--(lift,top)
        * 第二个(X,Y)--(lift,button)
        * 第三个个(X,Y)--(right,buttom)
        * */
        mPath.moveTo(lift, top);
        mPath.lineTo(lift, buttom);
        mPath.lineTo(right,buttom);

        //使用Path链接这三个坐标
        canvas.drawPath(mPath,linePaint);

        //----------------------------我们在这里添加一个绘制网格的方法----------------------------------------
        drawLines(canvas);
        // 释放画布
        canvas.restore();
    }

    private void drawLines(Canvas canvas) {

        // 重置线条画笔,因为是细线,所有我这里设置了2。
        linePaint.setStrokeWidth(2);

        // 假如我们有八条数据
        int count = pointFs.size();

        // 计算横纵坐标刻度间隔
        spaceY =(buttom - top) / count;
        spaceX =(right - lift) / count;

        Log.i("Text","spaceY:--"+spaceY);
        Log.i("Text","spaceX:--"+spaceX);
        // 计算除数的值为数据长度减一,8个数据,7条线。
        int divisor = count - 1;
        Log.i("Text","divisor:--"+divisor);

        // 计算横轴数据最大值
        maxX = 0;
        for (int i = 0; i < count; i++) {
            if (maxX < pointFs.get(i).x) {
                maxX = pointFs.get(i).x;//X轴最大坐标

            }
        }
        Log.i("Text","maxX:--"+maxX);
        // 计算横轴最近的能被count整除的值
        int remainderX = ((int) maxX) % divisor;
        maxX = remainderX == 0 ? ((int) maxX) : divisor - remainderX + ((int) maxX);


        // 计算纵轴数据最大值
        maxY = 0;
        for (int i = 0; i < count; i++) {
            if (maxY < pointFs.get(i).y) {
                maxY = pointFs.get(i).y;
            }
        }
        Log.i("Text","maxY:--"+maxY);
        // 计算纵轴最近的能被count整除的值
        int remainderY = ((int) maxY) % divisor;
        Log.i("Text","remainderY:--"+remainderY);

        if(remainderY == 0&&maxY==0){
            maxY=0;
        }else {
            maxY=divisor - remainderY + ((int) maxY);
            Log.i("Text","maxY11111111111:--"+maxY);
        }
//
//        // 生成横轴刻度值
//        rulerX = new float[count];
//        for (int i = 0; i < count; i++) {
//            rulerX[i] = maxX / divisor * i;
//        }
//        Log.i("Text","rulerX:--"+rulerX);
//
//        // 生成纵轴刻度值
//        rulerY = new float[count];
//        for (int i = 0; i < count; i++) {
//            rulerY[i] = maxY / divisor * i;
//        }
//        Log.i("Text","rulerY:--"+rulerY);

        // 锁定画布并设置画布透明度为75%
        int sc = canvas.saveLayerAlpha(0, 0, canvas.getWidth(), canvas.getHeight(), 75, Canvas.ALL_SAVE_FLAG);

        // 绘制横纵线段
        for (float y = buttom - spaceY; y >  top; y -= spaceY) {
            Log.i("Text","y"+y);

            for (float x =  lift; x < right; x += spaceX) {
                Log.i("Text","x"+x);
                /*
                 * 绘制纵向线段
                 */
                if (y == top + spaceY) {
                    canvas.drawLine(x, y, x, y + spaceY * (count - 1), linePaint);
                }

                /*
                 * 绘制横向线段
                 */
                if (x == right - spaceX) {
                    canvas.drawLine(x, y, x - spaceX * (count - 1), y, linePaint);
                }
            }
        }

        // 还原画布
        canvas.restoreToCount(sc);

    }



    private void drawXYelement(Canvas canvas) {
        // 锁定画布
        canvas.save();
        mTextPaint.setTextSize(36);//文字大小
  /*
        * Y轴文字提示
        * drawText(String ,x,y,TextPaint)
        * (lift,top)
        * */
        mTextPaint.setTextAlign(Paint.Align.LEFT);//左对齐
        canvas.drawText("Y",lift+20,top,mTextPaint);

        /*
        * X轴文字提示
        * drawText(String ,right,buttom,TextPaint)
        * */
        mTextPaint.setTextAlign(Paint.Align.RIGHT);//右对齐
        canvas.drawText("X",right,buttom+50,mTextPaint);
        // 释放画布
        canvas.restore();
    }

}

三,我们绘制,刻度上的值

技术分享

1、再根据我们绘制网格的点,来绘制我们的刻度

 int num = 0;//用于给X轴赋值
            int num_y  = 0;//用于给Y轴赋值

            for (float y = buttom - spaceY; y > top; y -= spaceY) {
            for (float x = lift; x < right; x += spaceX) {
                mTextPaint.setTextSize(28);

                /*
                 * 绘制横轴刻度数值
                 */
                if (y == buttom - spaceY) {
                    canvas.drawText(""+index_x[num], x-12, buttom+(top/3), mTextPaint);
                    Log.i("Text","num-"+num);
                }

                /*
                 * 绘制纵轴刻度数值
                 * 简单来说就是,Y轴上的坐标点,X轴是恒定不变的,但是Y轴是变化的(buttom - 间距)+10的距离向上绘制
                 */
                if (x == lift) {
                    canvas.drawText(""+index_y[num_y], lift - (lift/2), y + 10, mTextPaint);

                    Log.i("Text","lift:"+lift);
                    Log.i("Text","lift - (1/16):"+(lift - (lift/2)));

                }

                num++;
            }
                num_y++;
        }
    }

3、这个没什么说的,仔细在本子上画一下就明白了,也有注释;附上全部代码

package tester.ermu.com.polylinedemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PointF;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**/

public class XYView03 extends View {

    private int viewSize;//获取空间的尺寸,也就是我们布局的尺寸大小(不知道理解的是否正确)
    private Paint linePaint;// 线条画笔和点画笔

    private Path mPath;// 路径对象
    private TextPaint mTextPaint;// 文字画笔

    private List<PointF> pointFs = new ArrayList<>();// 数据列表
    private float[] rulerX, rulerY;// xy轴向刻度

    //上下左右坐标点
    private float lift ;
    private  float top ;
    private  float right ;
    private float buttom ;

    //Y轴文字坐标点
    private float PathY_X ;
    private float PathY_Y ;
    //X轴文字坐标点
    private float PathX_X ;
    private float PathX_Y ;

    private float maxX;//x轴最大值
    private float maxY;//Y轴最大值

    private float spaceX, spaceY;// 刻度间隔

    /*
    * 绘制X和Y轴对应的文字
    * */
    int[] index_x = {0,1,2,3,4,5,6,7};
    int[] index_y = {0,1,2,3,4,5,6,7};


    public XYView03(Context context, AttributeSet attrs) {
        super(context, attrs);
        //第一步,初始化对象
        linePaint = new Paint();
        linePaint.setColor(Color.YELLOW);//线条的颜色
        linePaint.setStrokeWidth(8);//线条的宽度
        linePaint.setAntiAlias(true);//取消锯齿
        linePaint.setStyle(Paint.Style.STROKE);//粗线


        //初始化Path
        mPath = new Path();

        mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG | Paint.LINEAR_TEXT_FLAG);
        mTextPaint.setColor(Color.WHITE);

        //模拟数据
        initData();
    }

    public XYView03(Context context) {
        super(context);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // 在我们没学习测量控件之前强制宽高一致
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    }
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        //第二步骤,我们在这里获取每个用到的坐标点和尺寸

        viewSize = w;//获取空间的尺寸,
        Log.i("Text","viewSize:"+viewSize);

        //这个是我们上下左右需要用到的坐标点
         lift = viewSize*(2/16f);
         top = viewSize*(2/16f);
         right = viewSize*(15/16f);
         buttom = viewSize*(8/16f);

        //下面是绘制X,Y轴提示文字
        /*
        * Y轴(PathY_X,PathY_Y)
        * */
         PathY_X =  viewSize*2/16;
         PathY_Y =  viewSize*1/16;

        /*
        * X轴(PathX_X,PathX_Y)
        * */
        PathX_X =  viewSize*15/16f;
        PathX_Y =  viewSize*9/16f;

    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 锁定画布
        canvas.save();


        //定义一个绘制X,Y轴的方法
        drawXY(canvas);


        //绘制X和Y轴上的提示文字
        drawXYelement(canvas);


    }
    private void initData() {
        Random random = new Random();
        pointFs = new ArrayList<PointF>();
        for (int i = 0; i < 8; i++) {
            PointF pointF = new PointF();

            pointF.x = (float) (random.nextInt(100) * i);
            pointF.y = (float) (random.nextInt(100) * i);

            pointFs.add(pointF);
        }
    }
    private void drawXY(Canvas canvas) {
        /*
        * 第三步,我们来通过viewSize尺寸来获取三个坐标点
        * 第一个(X,Y)--(lift,top)
        * 第二个(X,Y)--(lift,button)
        * 第三个个(X,Y)--(right,buttom)
        * */
        mPath.moveTo(lift, top);
        mPath.lineTo(lift, buttom);
        mPath.lineTo(right,buttom);

        //使用Path链接这三个坐标
        canvas.drawPath(mPath,linePaint);

        //----------------------------我们在这里添加一个绘制网格的方法----------------------------------------
        drawLines(canvas);
        // 释放画布
        canvas.restore();
    }

    private void drawLines(Canvas canvas) {
        Log.i("Text","1111111111111111111");
        /*
        * 1、我们需要知道X,Y轴的最大值是多少
        * 2、我们需要知道我们在X,Y轴分别有多少个点,然后每个点之间的间距是多少
        * 3、绘制网格线
        * */

        // 重置线条画笔,因为是细线,所有我这里设置了2。
        linePaint.setStrokeWidth(2);

        // 假如我们有八条数据
        int count = pointFs.size();


        // 计算横纵坐标刻度间隔
        spaceY =(buttom - top) / count;
        spaceX =(right - lift) / count;

        Log.i("Text","spaceY:--"+spaceY);
        Log.i("Text","spaceX:--"+spaceX);
        // 计算除数的值为数据长度减一,8个数据,7条线。
        int divisor = count - 1;
        Log.i("Text","divisor:--"+divisor);

        // 计算横轴数据最大值
        maxX = 0;
        for (int i = 0; i < count; i++) {
            if (maxX < pointFs.get(i).x) {
                maxX = pointFs.get(i).x;//X轴最大坐标

            }
        }
        Log.i("Text","maxX:--"+maxX);
        // 计算横轴最近的能被count整除的值
        int remainderX = ((int) maxX) % divisor;
        maxX = remainderX == 0 ? ((int) maxX) : divisor - remainderX + ((int) maxX);


        // 计算纵轴数据最大值
        maxY = 0;
        for (int i = 0; i < count; i++) {
            if (maxY < pointFs.get(i).y) {
                maxY = pointFs.get(i).y;
            }
        }
        Log.i("Text","maxY:--"+maxY);
        // 计算纵轴最近的能被count整除的值
        int remainderY = ((int) maxY) % divisor;
        Log.i("Text","remainderY:--"+remainderY);

        if(remainderY == 0&&maxY==0){
            maxY=0;
        }else {
            maxY=divisor - remainderY + ((int) maxY);
            Log.i("Text","maxY11111111111:--"+maxY);
        }

        // 锁定画布并设置画布透明度为75%
        int sc = canvas.saveLayerAlpha(0, 0, canvas.getWidth(), canvas.getHeight(), 75, Canvas.ALL_SAVE_FLAG

        // 绘制横纵线段
        for (float y = buttom - spaceY; y >  top; y -= spaceY) {
            Log.i("Text","y"+y);

            for (float x =  lift; x < right; x += spaceX) {
                Log.i("Text","x"+x);
                /*
                 * 绘制纵向线段
                 */
                if (y == top + spaceY) {
                    canvas.drawLine(x, y, x, y + spaceY * (count - 1), linePaint);
                }

                /*
                 * 绘制横向线段
                 */
                if (x == right - spaceX) {
                    canvas.drawLine(x, y, x - spaceX * (count - 1), y, linePaint);
                }
            }
        }

        // 还原画布
        canvas.restoreToCount(sc);




            int num = 0;//用于给X轴赋值
            int num_y  = 0;//用于给Y轴赋值

            for (float y = buttom - spaceY; y > top; y -= spaceY) {
            for (float x = lift; x < right; x += spaceX) {
                mTextPaint.setTextSize(28);

                /*
                 * 绘制横轴刻度数值
                 */
                if (y == buttom - spaceY) {
                    canvas.drawText(""+index_x[num], x-12, buttom+(top/3), mTextPaint);
                    Log.i("Text","num-"+num);
                }

                /*
                 * 绘制纵轴刻度数值
                 * 简单来说就是,Y轴上的坐标点,X轴是恒定不变的,但是Y轴是变化的(buttom - 间距)+10的距离向上绘制
                 */
                if (x == lift) {
                    canvas.drawText(""+index_y[num_y], lift - (lift/2), y + 10, mTextPaint);

                    Log.i("Text","lift:"+lift);
                    Log.i("Text","lift - (1/16):"+(lift - (lift/2)));

                }

                num++;
            }
                num_y++;
        }
    }



    private void drawXYelement(Canvas canvas) {
        // 锁定画布
        canvas.save();
        mTextPaint.setTextSize(36);//文字大小

        /*
        * Y轴文字提示
        * drawText(String ,x,y,TextPaint)
        * (lift,top)
        * */
        mTextPaint.setTextAlign(Paint.Align.LEFT);//左对齐
        canvas.drawText("Y",PathY_X,PathY_Y,mTextPaint);


        /*
        * X轴文字提示
        * drawText(String ,right,buttom,TextPaint)
        * */
        mTextPaint.setTextAlign(Paint.Align.RIGHT);//右对齐
        canvas.drawText("X",PathX_X,PathX_Y,mTextPaint);
        // 释放画布
        canvas.restore();
    }

}

四,我们给我们的网格区域来绘制一个遮盖层,效果如下

技术分享

1、我们直接绘制一张半透明的图即可

private void drawbitmaps(Canvas canvas) {
        /*
        我们给我们的区域先绘制一个颜色模块,做法很简单,生成一个图片即可,然后透明度设置下
        * Bitmap.createBitmap()
        * 关于他的6个方法,可查看博客:http://www.cnblogs.com/wangxiuheng/p/4503610.html
        * */


        Bitmap mBitmap = Bitmap.createBitmap((int)(right-lift-spaceX),(int)(buttom-top-spaceY),Bitmap.Config.ARGB_8888);

        mCanvas.setBitmap(mBitmap);

        /*
        * 为画布填充一个半透明的红色
        * drawARGB(a,r,g,b)
        * a:透明度
        * r:红色
        * g:绿色
        * b:蓝色
        * */
        mCanvas.drawARGB(55, 255, 0, 0);

        // 重置曲线
        mPath.reset();
        // 将mBitmap绘制到原来的canvas
        canvas.drawBitmap(mBitmap, lift, top+spaceY , null);


        //绘制我们的坐标点
//         drawText(canvas);
    }

2、在onDraw调用即可

  @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 锁定画布
        canvas.save();


        //定义一个绘制X,Y轴的方法
        drawXY(canvas);


        //绘制X和Y轴上的提示文字
        drawXYelement(canvas);

        //最后遮罩层图
        drawbitmaps(canvas);
//
    }

五、最后就是绘制我们的折现了

技术分享

注意:,当然是根据我们传递过来的数据了,切记,在没有数据的时候,我默认生成的8个数据,为了避免Main传递过来的是空数据

 private void initData() {
        Random random = new Random();
        pointFs = new ArrayList<PointF>();
        for (int i = 0; i < 8; i++) {
            PointF pointF = new PointF();

            pointF.x = (float) (random.nextInt(60) * i);
            pointF.y = (float) (random.nextInt(60) * i);

            pointFs.add(pointF);
        }
    }

1、我们来在Main中写一些数据,然后传递给我们自定义的view

package tester.ermu.com.polylinedemo;

import android.graphics.PointF;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private XYView05 xyview05;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    init();
}

private void init() {
        xyview05 = (XYView05) findViewById(R.id.My_XYView04);

        List<PointF> pointFs = new ArrayList<PointF>();
        pointFs.add(new PointF(0.3F, 0.5F));
        pointFs.add(new PointF(1F, 22.7F));
        pointFs.add(new PointF(2F, 33.5F));
        pointFs.add(new PointF(3F, 36.2F));
        pointFs.add(new PointF(4F, 18.8F));
        pointFs.add(new PointF(5F, 15.5F));
        pointFs.add(new PointF(6F, 24.2F));
        pointFs.add(new PointF(7F, 52.5F));

        xyview05.setData(pointFs, "X轴提示文字", "Y轴提示文字",MainActivity.this);
        }

        }

2、我们通过setData()方法来接受这些数据


    public synchronized void setData(List<PointF> pointFs, String signX, String signY, Activity activity) {
        /*
         * 数据为空直接提示下
         */
        if (null == pointFs || pointFs.size() == 0)
            throw new IllegalArgumentException("No data to display !");

        /*
         * 控制数据长度不超过10个
         * 对于折线图来说数据太多就没必要用折线图表示了而是使用散点图
         */
        if (pointFs.size() > 10)
            throw new IllegalArgumentException("The data is too long to display !");

        // 设置数据并重绘视图
        this.pointFs = pointFs;
        this.context = activity;

        invalidate();
    }

3、那么我们来通过drawText(Canvas canvas)方法处理这些数据来绘制点和连接这些点的折线

    private void drawText(Canvas canvas) {
        Paint pointPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG);
        pointPaint.setStyle(Paint.Style.FILL);//焦点的类型
        pointPaint.setColor(Color.WHITE);//焦点的颜色

        if(pointFs.size()==0){
            Toast.makeText(context,"暂无折现数据",Toast.LENGTH_SHORT).show();
        }else {
                /*
         * 生成Path和绘制Point
         */
            for (int i = 0; i < pointFs.size(); i++) {
                // 计算x坐标
                float x = mCanvas.getWidth() / maxX * pointFs.get(i).x;
                // 计算y坐标
                float y = mCanvas.getHeight() / maxY * pointFs.get(i).y;
                y = mCanvas.getHeight() - y;

                // 绘制小点点
                mCanvas.drawCircle(x, y, 6, pointPaint);

            /*
             * 如果是第一个点则将其设置为Path的起点
             */
                if (i == 0) {
                    mPath.moveTo(x, y);
                }

                // 连接各点
                mPath.lineTo(x, y);
            }

            // 设置PathEffect
            linePaint.setPathEffect(new CornerPathEffect(10));

            // 重置线条宽度
            linePaint.setStrokeWidth(4);

            // 将Path绘制到我们自定的Canvas上
            mCanvas.drawPath(mPath, linePaint);
        }
    }

4、注意,我们需要刻度值来绘制我们的点坐标,不要乱赋值,

      // 生成横轴刻度值
        rulerX = new float[count];
        for (int i = 0; i < count; i++) {
            rulerX[i] = maxX / divisor * i;
        }
//        Log.i("Text","rulerX:--"+rulerX);

        // 生成纵轴刻度值
        rulerY = new float[count];
        for (int i = 0; i < count; i++) {
            rulerY[i] = maxY / divisor * i;
        }

六:本章demo:http://download.csdn.net/detail/bobo8945510/9695960

如果想改变折现的样子或平滑度,请看:http://blog.csdn.net/bobo8945510/article/details/53213938

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    自定义view—折线图