Android绘制折线图
.'~'. 人气:0一.总体设计
1.寻找规律,公式化的生成坐标系。
2.将生成坐标系的关键参数设置为可自定义,从而可变的可以生成自己想要的坐标系。
3.将需要绘制的点绘制在坐标系中并生成折现图。
二.具体模块实现
1.坐标系的生成:
public void chart(){ imageView=(ImageView)findViewById(R.id.image); newb = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); canvasTemp = new Canvas(newb); //Canvas canvasTemp2=new Canvas(newb); canvasTemp.drawColor(Color.TRANSPARENT); p = new Paint(); //防锯齿 p.setAntiAlias(true); p.setStyle(Paint.Style.STROKE);//STROKE,FILL p.setStrokeWidth(5); p.setColor(Color.LTGRAY); p.setTextAlign(Paint.Align.CENTER); p.setTextSize(40); p.setColor(Color.BLACK); p.setStyle(Paint.Style.FILL);//STROKE,FILL p.setStrokeWidth(2); p2=p; //绘制表格 canvasTemp.drawText("0", startx1-10, starty1+30, p);//原点 canvasTemp.drawLine(startx1,starty1, endx1+50,starty1,p);// 绘制x轴 canvasTemp.drawText("x", endx1+50+10, starty1+35, p); //标记x轴 canvasTemp.drawLine(startx1,starty1, startx1,endy1-50,p);// 绘制y轴 canvasTemp.drawText("y", startx1-15,endy1-50, p); //标记y轴 //绘制x y轴箭头 canvasTemp.drawLine(endx1+50,starty1, endx1+50-10,starty1-10,p); canvasTemp.drawLine(endx1+50,starty1, endx1+50-10,starty1+10,p); canvasTemp.drawLine(startx1,endy1-50, startx1-10,endy1-50+10,p); canvasTemp.drawLine(startx1,endy1-50, startx1+10,endy1-50+10,p); //绘制x轴间隔线 for(int i=1;i<=allX;i++){ canvasTemp.drawLine(startx1+xinterval*i,starty1, startx1+xinterval*i,starty1-10,p); if(allX>30){ p2.setTextSize(20); } canvasTemp.drawText(String.valueOf(i), startx1+xinterval*i, starty1+35, p2); } //绘制y轴间隔线 for(int i=1;i<=allY;i++){ canvasTemp.drawLine(startx1,starty1-yinterval*i, startx1+10,starty1-yinterval*i,p); if(allX>25){ p2.setTextSize(20); }else{ p2.setTextSize(35); canvasTemp.drawText(String.valueOf( (i*fully/allY)), startx1-55, starty1-yinterval*i+10, p2); } } imageView.setImageBitmap(newb); }
2.自定义坐标系参数获取并绘制:
public void comfir(View view) { EditText numberx=(EditText)findViewById(R.id.numberx); EditText numbery=(EditText)findViewById(R.id.numbery); EditText maxy=(EditText)findViewById(R.id.maxy); if(!numberx.getText().toString().trim().equals("")&&!numbery.getText().toString().trim().equals("")&&!maxy.getText().toString().trim().equals("")){ /*//判断输入框中内容是否为空的错误方法: numberx.getText()!=null; numberx.getText().toString()!=null; numberx.getText().toString().equals("");*/ allX= Integer.valueOf(String.valueOf(numberx.getText())); allY= Integer.valueOf(String.valueOf(numbery.getText())); fully= Integer.valueOf(String.valueOf(maxy.getText())); xinterval=(endx1-startx1)/allX; yinterval=(starty1-endy1)/allY; //rule1=(starty1-endy1)/allY; //rule2=(starty1-endy1)/fully; mypoint=new float[allX]; all=0; chart(); } }
3.将输入的点绘制在坐标系中:
public void paint(View view) { EditText point=(EditText)findViewById(R.id.point); if(all==fully){ Toast.makeText(this,"已达最大x值",Toast.LENGTH_SHORT).show(); point.setText(""); }else{ if(!point.getText().toString().trim().equals("")){ thispoint=Float.valueOf(String.valueOf(point.getText())); if(thispoint>fully){ Toast.makeText(this,"大于最大y值,请重新输入!",Toast.LENGTH_SHORT).show(); point.setText(""); }else{ mypoint[all]=thispoint; x2=startx1+xinterval*(all+1); y2=starty1-thispoint/fully*rule1; p.setStrokeWidth(10); canvasTemp.drawPoint(x2,y2,p); if(all>0){ p.setStrokeWidth(5); canvasTemp.drawLine(x1,y1,x2,y2,p); } all++; } x1=x2; y1=y2; } } point.setText(""); }
三.效果展示
”确认”键上面三个参数可实现对坐标系的自定义。“清除所有”按钮会将折线图清除,不会将坐标系也清除。
四.功能展望
1.多个折现图同时展示。
2.加入颜色元素增加美观性。
3.更改或优化折线图数据输入方式。
总结
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