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我正在嘗試編寫一個應用程序，該應用程序連接到遠程主機並讀取x，y元組的行並將它們實時繪製爲散點圖。數據正在按預期顯示，但是當我修改代碼以嘗試顯示某些標記以測量數據時，該數據未按預期工作。我期望看到20個同心灰色圓圈的黑色背景。隨着數據的滾入，它應該在同心圓上顯示爲綠色圓點。相反，我在遠程主機關閉時看到的是initializeSurface（）被調用，並且只顯示外部灰色圓圈（i = 20）。而且，當遠程主機啓動initializeSurface（）後，快速調用drawPoint（），並且不顯示灰色圓圈，只顯示綠色圓點。代碼如下，之後是之前描述的2個屏幕截圖。Android：繪製同心圓
package com.balaguru.ggdiagram;
import android.app.Activity;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.WindowManager;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.Socket;
class ToastThread implements Runnable {
private String ivMessage;
private View ivView;
ToastThread(View pView, String pMessage) { ivView = pView; ivMessage = pMessage; }
public void run() {
Toast.makeText(ivView.getContext(), ivMessage, Toast.LENGTH_LONG).show();
}
}
class ConnectionThread extends Thread {
private GGView ivGGView;
ConnectionThread(GGView pGGView) {
ivGGView = pGGView;
}
public void run() {
try {
ivGGView.initializeSurface();
//Toast.makeText(MainActivity.context, "office-main", Toast.LENGTH_LONG).show();
Socket socket = new Socket("192.168.1.197", 10000);
BufferedReader input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String line = input.readLine();
while (line != null) {
if (line.equals("not connected")) {
ivGGView.drawPoint(0, 0, Color.GREEN);
} else {
String[] gg = line.split(",");
float x = Float.parseFloat(gg[0]);
float y = Float.parseFloat(gg[1]);
ivGGView.drawPoint(x, y, Color.GREEN);
}
line = input.readLine();
}
} catch (Throwable e) {
StringWriter error = new StringWriter();
e.printStackTrace(new PrintWriter(error));
ToastThread toast = new ToastThread(ivGGView, error.toString());
Activity activity = (Activity) ivGGView.getContext();
activity.runOnUiThread(toast);
}
}
}
class GGView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder ivHolder;
public Context ivContext;
private int ivWidth;
private int ivHeight;
public GGView(Context context){
super(context);
ivContext = context;
ivHolder = getHolder();
ivHolder.addCallback(this);
}
public void surfaceDestroyed(SurfaceHolder pHolder) {}
public void surfaceCreated(SurfaceHolder pHolder) {
ConnectionThread thread = new ConnectionThread(this);
thread.start();
}
public void surfaceChanged(SurfaceHolder pHolder, int pFormat, int pWidth, int pHeight) {}
public void initializeSurface() {
Canvas canvas = ivHolder.lockCanvas();
ivWidth = canvas.getWidth();
ivHeight = canvas.getHeight();
canvas.drawColor(Color.BLACK);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.GRAY);
paint.setStrokeWidth(4);
paint.setStyle(Paint.Style.STROKE);
for (int i = 1; i <= 20; i++) {
canvas.drawArc(ivWidth/2 - i/20*ivHeight/2,
ivHeight/2 - i/20*ivHeight/2,
ivWidth/2 + i/20*ivHeight/2,
ivHeight/2 + i/20*ivHeight/2,
0, 360, false, paint);
}
ivHolder.unlockCanvasAndPost(canvas);
}
public void drawPoint(float pX, float pY, int pColor) {
float x = pX/20 * ivHeight/2 + ivWidth/2;
float y = pY/20 * ivHeight/2 + ivHeight/2;
Canvas canvas = ivHolder.lockCanvas(
new Rect((int) x-4, (int)y-4, (int) x+4, (int)y+4));
Paint paint = new Paint();
paint.setColor(pColor);
paint.setStrokeWidth(4);
canvas.drawPoint(x, y, paint);
ivHolder.unlockCanvasAndPost(canvas);
}
}
public class MainActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
GGView ggView = new GGView(this);
setContentView(ggView);
}
}
EDIT 如果我改變for循環從20到40中initializeSurface（）然後drawArc似乎繪製同心圓當i = 20和i = 40，但沒有其他。下面的屏幕截圖。
