我是 android 新手，我需要知道如何使图形或图表（例如折线图）移动，即从右到左。
基本上我会按照手机的RAM Memory Usage来绘制图表。我需要在 Windows 的任务管理器中绘制一个类似的图形。
请帮助解决这个问题。
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5141 次
3 回答
3
看看这堂课。
它简单实用。
原作者是 Arno den Hond，谷歌一下。
我重新设计了这个类。
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Align;
import android.view.View;
/**
* GraphView creates a scaled line or bar graph with x and y axis labels.
* @author Arno den Hond
* @redesign Reinhard & kimkmkm
*
*/
public class GraphView extends View {
public static boolean BAR = true;
public static boolean LINE = false;
private Paint paint;
private float[] values;
private String[] horlabels;
private String[] verlabels;
private String title;
private boolean type;
/**
* Generate Graph
* Variable Array for GraphView
* verlabel : Background Height Values
* horlabel : Background Width Values
* values : Max Values of Foreground Active Graph
*
* basic draw rule
* if Array is not null
* Draw Background width, height & active Graph all time
* or Array is null
* Draw Background width, height
* active Graph fixed 0
*
*/
public GraphView(Context context, float[] values, String title, String[] horlabels, String[] verlabels, boolean type) {
super(context);
if (values == null)
values = new float[0];
else
this.values = values;
if (title == null)
title = "";
else
this.title = title;
if (horlabels == null)
this.horlabels = new String[0];
else
this.horlabels = horlabels;
if (verlabels == null)
this.verlabels = new String[0];
else
this.verlabels = verlabels;
this.type = type;
paint = new Paint();
}
/**
* Graph for Background
* &
* Value for Background
*/
@Override
protected void onDraw(Canvas canvas) {
float border = 20;
float horstart = border * 2;
float height = getHeight();
float width = getWidth() - 1;
float max = 700;
float min = 0;
float diff = max - min;
float graphheight = height - (2 * border);
float graphwidth = width - (2 * border);
paint.setTextAlign(Align.LEFT);
/** vers : BackGround Height Values length*/
int vers = verlabels.length - 1;
for (int i = 0; i < verlabels.length; i++) {
paint.setColor(Color.LTGRAY);
// Width Line of background
float y = ((graphheight / vers) * i) + border;
// float y : ((getHeight / Height values length) * Height values length ) + 20
canvas.drawLine(horstart, y, width, y, paint);
// drawLine ( 40, y, getWidth()-1, y, paint)
paint.setColor(Color.WHITE);
// Left Height of background
canvas.drawText(verlabels[i], 0, y, paint);
}
/** hors : BackGround width Values length*/
int hors = horlabels.length - 1;
for (int i = 0; i < horlabels.length; i++) {
// Height Line of background
paint.setColor(Color.DKGRAY);
float x = ((graphwidth / hors) * i) + horstart;
canvas.drawLine(x, height - border, x, border, paint);
paint.setTextAlign(Align.CENTER);
if (i==horlabels.length-1)
paint.setTextAlign(Align.RIGHT);
if (i==0)
paint.setTextAlign(Align.LEFT);
// Value of Width
paint.setColor(Color.WHITE);
canvas.drawText(horlabels[i], x, height - 4, paint);
}
paint.setTextAlign(Align.CENTER);
canvas.drawText(title, (graphwidth / 2) + horstart, border - 4, paint);
/**
* Yellow Line Graph
* continue Repaint....
*
*/
if (max != min) {
paint.setColor(Color.YELLOW);
if (type == BAR) {
float datalength = values.length;
float colwidth = (width - (10 * border)) / datalength;
for (int i = 0; i < values.length; i++) {
float val = values[i] - min;
float rat = val / diff;
//diff : max - min
float h = graphheight * rat;
canvas.drawRect((i * colwidth) + horstart, (border - h) + graphheight, ((i * colwidth) + horstart) + (colwidth - 1), height - (border - 1), paint);
}
} else {
float datalength = values.length;
float colwidth = (width - (2 * border)) / datalength;
float halfcol = colwidth / 2;
float lasth = 0;
for (int i = 0; i < values.length; i++) {
float val = values[i] - min;
float rat = val / diff;
float h = graphheight * rat;
if (i > 0)
canvas.drawLine(((i - 1) * colwidth) + (horstart + 1) + halfcol, (border - lasth) + graphheight, (i * colwidth) + (horstart + 1) + halfcol, (border - h) + graphheight, paint);
lasth = h;
}
}
}
}
于 2012-06-12T08:47:17.043 回答
2
这是我的示例代码。
我还没有测试。
但我认为这段代码工作正常。
public class DrawGraph extends Activity{
/**
* Variable Array for GraphView
* verlabel : Background Height Values
* horlabel : Background Width Values
* values : Max Values of Foreground Active Graph
*/
private float[] values = new float[60];
private String[] verlabels = new String[] { "600","500","400","300","200","100","80","60","40","20","0", };
private String[] horlabels = new String[] { "0","10", "20", "30", "40", "50", "60"};
private GraphView graphView;
private LinearLayout graph;
private boolean runnable = false;
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
graph = (LinearLayout)findViewById(R.id.graph);
graphView = new GraphView(DrawGraph.this, values, "TEST GRAPH", horlabels, verlabels, GraphView.LINE);
graph.addView(graphView);
runnable = true;
startDraw.start();
}
@Override
public void onDestroy(){
super.onDestroy();
runnable = false;
}
public void setGraph(int data){
for(int i=0; i<values.length-1; i++){
values[i] = values[i+1];
}
values[values.length-1] = (float)data;
graph.removeView(graphView);
graph.addView(graphView);
}
public Handler handler = new Handler(){
@Override
public void handleMessage(android.os.Message msg){
switch(msg.what){
case 0x01:
int testValue = (int)(Math.random() * 600)+1;
setGraph(testValue);
break;
}
}
}
public Thread startDraw = new Thread(){
@Override
public void run(){
while(runnable){
handler.sendEmptyMessage(0x01);
try{
Thread.sleep(1000);
} catch (Exception e){
e.printstacktrace();
}
}
}
}
于 2012-06-13T09:35:28.223 回答
0
试试AndroidPlot，这是一个简单易用的库！
另请参阅chartengine。
于 2012-06-12T08:57:14.570 回答