折线图以及渐变

图：

View:

package com.example.test_chart;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Shader;
import android.view.View;

public class ChartViewextends View{
    public int XPoint=30;    //原点的X坐标
    public int YPoint=280;     //原点的Y坐标
    public int XScale=40;     //X的刻度长度
    public int YScale=40;     //Y的刻度长度
    public int XLength=240;        //X轴的长度
    public int YLength=240;        //Y轴的长度
    public String[] XLabel;   //X的刻度
    public String[] YLabel;   //Y的刻度
    public String[] Data;     //数据
    public String Title;   //显示的标题
    
    public ChartView(Context context){
        super(context);
    }
    
    public void SetInfo(String[] XLabels,String[] YLabels,String[] AllData,String strTitle){
        XLabel=XLabels;
        YLabel=YLabels;
        Data=AllData;
        Title=strTitle;
    }
    
    @Override
    protected void onDraw(Canvas canvas){
        super.onDraw(canvas);//重写onDraw方法

        canvas.drawColor(Color.DKGRAY);//设置背景颜色
        Paint paint = null;
        
        Paint paint2= new Paint();
        paint2.setStyle(Paint.Style.STROKE);
        paint2.setAntiAlias(true);//去锯齿
        paint2.setColor(Color.BLUE);//颜色
        
        Paint paint1=new Paint();
        paint1.setStyle(Paint.Style.STROKE);
        paint1.setAntiAlias(true);//去锯齿
        paint1.setColor(Color.GREEN);
        
        paint = paint1;
        
        paint.setTextSize(12);  //设置轴文字大小
        
        /* 设置渐变色 颜色是改变的 */  
        Shader mShader = new LinearGradient(0, 0, 100, 100,
                new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW,  
                        Color.LTGRAY }, null, Shader.TileMode.REPEAT); // 一个材质,打造出一个线性梯度沿著一条线。  
        paint.setShader(mShader);
        //设置Y轴
        canvas.drawLine(XPoint, YPoint-YLength, XPoint, YPoint, paint);   //轴线
        for(int i=0;i*YScale<YLength ;i++)                
        {
            canvas.drawLine(XPoint,YPoint-i*YScale,XPoint+5, YPoint-i*YScale, paint); //刻度
            try
            {
                canvas.drawText(YLabel[i] ,XPoint-22, YPoint-i*YScale+5, paint); //文字
            }
            catch(Exception e)
            {
            }
        }
        canvas.drawLine(XPoint,YPoint-YLength,XPoint-3,YPoint-YLength+6,paint); //箭头
        canvas.drawLine(XPoint,YPoint-YLength,XPoint+3,YPoint-YLength+6,paint);
        
        //设置X轴
        canvas.drawLine(XPoint,YPoint,XPoint+XLength,YPoint,paint);  //轴线
        for(int i=0;i*XScale<XLength;i++)    
        {
            canvas.drawLine(XPoint+i*XScale,YPoint, XPoint+i*XScale,YPoint-5, paint);  //刻度
            try
            {
                canvas.drawText(XLabel[i] ,XPoint+i*XScale-10, YPoint+20, paint);  //文字
                //数据值
                    if(i>0&&YCoord(Data[i-1])!=-999&&YCoord(Data[i])!=-999) //保证有效数据
                        canvas.drawLine(XPoint+(i-1)*XScale, YCoord(Data[i-1]),XPoint+i*XScale, YCoord(Data[i]), paint);
                    canvas.drawCircle(XPoint+i*XScale,YCoord(Data[i]), 2, paint);
           }
            catch(Exception e)
            {
            }
        }
        canvas.drawLine(XPoint+XLength,YPoint,XPoint+XLength-6,YPoint-3,paint);   //箭头
        canvas.drawLine(XPoint+XLength,YPoint,XPoint+XLength-6,YPoint+3,paint);  
        paint.setTextSize(16);
        canvas.drawText(Title, 150, 50, paint);
    }
    private int YCoord(String y0) //计算绘制时的Y坐标，无数据时返回-999
    {
        int y;
        try
        {
            y=Integer.parseInt(y0);
        }
        catch(Exception e)
        {
            return -999;    //出错则返回-999
        }
        try
        {
            return YPoint-y*YScale/Integer.parseInt(YLabel[1]);
        }
        catch(Exception e)
        {
        }
        return y;
    }
}

java:

package com.example.test_chart;


import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;


public class MainActivity extends Activity {


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

ChartView myView=new ChartView(this);
myView.SetInfo(
       new String[]{"7-11","7-12","7-13","7-14","7-15","7-16","7-17"},   //X轴刻度
       new String[]{"","50","100","150","200","250"},   //Y轴刻度
       new String[]{105+"",203+"",100+"",46+"",95+"",80+"",102+""},  //数据
       "图标的标题"
);


setContentView(myView);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}


}