我创建了一个名为 CustomViewVisual1 的自定义视图，它在 Particle 类的屏幕对象上绘制。我在扩展 Activity 的名为 LayoutCanvas 的类中使用此自定义视图。LayoutCanvas 中的 onTouch() 或 onProgressChanged() 事件似乎都不会导致我的视图重绘，即使我调用了 invalidate 并且也尝试了 postInvalidate()。我的对象的值发生了变化，但我没有重绘！老实说，我是 Android 新手，不知道如何设计我的类以及在哪里实现什么的任何好的做法，所以如果有人对我想要实现的目标有更好的解决方案，请告诉我。提前致谢！
这是粒子类：
public class Particle {
Rect rect = new Rect();
float similarity;
Point p = new Point();
float x;
float y;
float tx = 240;
float ty = 320;
Matrix transform = new Matrix();
float r;
Paint _paint = new Paint();
Paint tempp = new Paint();
Particle(){}
Particle(int width, float similarity){
this.similarity = similarity;
x = MyMath.map(similarity, 0, 1, 0, width/2);
//y = MyMath.myRandom(-20, 20);
y = 0;
//p.set((int) MyMath.map(similarity, 0, 1, 0, width/2), (int)MyMath.myRandom(0, 360));
p.set((int)x, (int)y);
r = MyMath.myRandom(0, 360);
//recalculateCoordinates();
_paint.setColor(Color.WHITE);
tempp.setColor(Color.GREEN);
//rotate(r);
}
public void display(Canvas canvas, Paint paint, float scale){
//canvas.drawLine(canvas.getWidth()/2, 0, canvas.getWidth()/2, canvas.getHeight(), _paint);
//canvas.drawLine(0, canvas.getHeight()/2, canvas.getWidth(), canvas.getHeight()/2, _paint);
canvas.save();
canvas.translate(canvas.getWidth()/2, canvas.getHeight()/2);
//canvas.translate(tx, ty);
canvas.rotate(r);
//canvas.scale(scale, scale);
paint.setColor(colorize());
canvas.drawRect(-p.x, p.y, -p.x+10, p.y+10, paint);
canvas.restore();
canvas.save();
canvas.translate(canvas.getWidth()/2, canvas.getHeight()/2);
canvas.drawLine(0, 0, 200, 0, tempp);
canvas.drawText("0'", 100, 8, tempp);
canvas.restore();
canvas.save();
canvas.translate(canvas.getWidth()/2, canvas.getHeight()/2);
canvas.rotate(45);
canvas.drawLine(0, 0, 200, 0, tempp);
canvas.drawText("45''", 100, 8, tempp);
canvas.restore();
canvas.save();
canvas.translate(canvas.getWidth()/2, canvas.getHeight()/2);
canvas.rotate(90);
canvas.drawLine(0, 0, 200, 0, tempp);
canvas.drawText("90'", 100, 8, tempp);
canvas.restore();
canvas.save();
canvas.translate(canvas.getWidth()/2, canvas.getHeight()/2);
canvas.rotate(180);
canvas.drawLine(0, 0, 200, 0, tempp);
canvas.drawText("180'", 100, 8, tempp);
canvas.restore();
}
public int colorize(){
return Color.argb(100, Math.round(255-MyMath.map(similarity, 0, 1, 0, 255)), 0, Math.round(MyMath.map(similarity, 0, 1, 0, 255)));
}
public void rotate(float degrees){
transform.setTranslate(120, 160);
transform.setRotate(degrees, 0, 0);
// Create new float[] to hold the rotated coordinates
float[] pts = new float[2];
// Initialize the array with our Coordinate
pts[0] = p.x;
pts[1] = p.y;
// Use the Matrix to map the points
transform.mapPoints(pts);
p.set((int)pts[0], (int)pts[1]);
// NOTE: pts will be changed by transform.mapPoints call
// after the call, pts will hold the new cooridnates
// Now, create a new Point from our new coordinates
//Point newPoint = new Point((int)pts[0], (int)pts[1]);
// Return the new point
//p.set(newPoint.x, newPoint.y);
//return newPoint;
}
public void translate(int x, int y){
tx = x;
ty = y;
}
public void recalculateCoordinates(){
x = (float) ( (x * android.util.FloatMath.cos(r) ) - (y * android.util.FloatMath.sin(r) ) );
y = (float) ( (x * android.util.FloatMath.sin(r) ) - (y * android.util.FloatMath.cos(r) ) );
}
/**
* @return the similarity
*/
public float getSimilarity() {
return similarity;
}
/**
* @param similarity the similarity to set
*/
public void setSimilarity(float similarity) {
this.similarity = similarity;
}
/**
* @return the x
*/
public float getX() {
return x;
}
/**
* @param x the x to set
*/
public void setX(float x) {
this.x = x;
}
/**
* @return the y
*/
public float getY() {
return y;
}
/**
* @param y the y to set
*/
public void setY(float y) {
this.y = y;
}
/**
* @return the r
*/
public float getR() {
return r;
}
/**
* @param r the r to set
*/
public void setR(float r) {
this.r = r;
}
public Point getP() {
return p;
}
public void setP(Point p) {
this.p = p;
}
}
这是 CustomViewVisual1 类：
public class CustomViewVisual1 extends View implements Runnable{
int width;
int height;
int x = 0;
int y = 0;
int canvasScale = 1;
int countDraw = 0;
Thread t = null;
boolean isItOK = false;
Paint paint;
Particle[] p = new Particle[500];
public CustomViewVisual1(Context context){
super(context);
initView();
}
public CustomViewVisual1(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
private void initView() {
// TODO Auto-generated method stub
paint = new Paint();
Random r = new Random();
for (int i = 0; i < p.length; i++) {
p[i] = new Particle(width, r.nextFloat());
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
// TODO Auto-generated method stub
super.onSizeChanged(w, h, oldw, oldh);
width = w;
height = h;
x = width/2;
y = height/2;
initView();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//canvas.translate(width/2, height/2);
canvas.drawARGB(255, 0, 0, 0);
canvas.scale(canvasScale, canvasScale);
for (int i = 0; i < p.length; i++) {
p[i].display(canvas, paint, canvasScale);
}
paint.setColor(Color.WHITE);
canvas.drawCircle(x, y, 20, paint);
/*
paint.setColor(Color.CYAN);
canvas.drawRect(0, 0, width, 10, paint);
paint.setColor(Color.GREEN);
canvas.drawRect(0, height-10, width, height, paint);
paint.setColor(Color.YELLOW);
canvas.drawRect(0, 0, 10, height, paint);
paint.setColor(Color.MAGENTA);
canvas.drawRect(width-10, 0, width, height, paint);
*/
countDraw++;
Log.d("How many draw = ", ""+countDraw);
}
public float getCanvasScale() {
return canvasScale;
}
public void setCanvasScale(int canvasScale) {
this.canvasScale = canvasScale;
}
public void pause() {
isItOK = false;
while (true) {
try {
t.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
break;
}
t = null;
}
public void resume() {
isItOK = true;
t = new Thread(this);
t.start();
}
@Override
public void run() {
// TODO Auto-generated method stub
}
}
这是 LayoutCanvas 类：
public class LayoutCanvas extends Activity implements OnTouchListener{
RelativeLayout rl;
SeekBar sb;
CustomViewVisual1 cView;
/*
* (non-Javadoc)
*
* @see android.app.Activity#onCreate(android.os.Bundle)
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_layout_canvas);
cView = new CustomViewVisual1(this);
cView.setOnTouchListener(this);
rl = (RelativeLayout) findViewById(R.id.lay_canvas);
rl.setOnTouchListener(this);
rl.setOnLongClickListener(new OnLongClickListener(){
@Override
public boolean onLongClick(View v) {
// TODO Auto-generated method stub
Log.d("on long touch", "keep touching");
return false;
}});
sb = (SeekBar) findViewById(R.id.sb_activity_layout_canvas);
sb.setOnSeekBarChangeListener(new OnSeekBarChangeListener(){
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
Log.d("in progress changed", "before if() "+progress);
if(progress > 0 && progress <=10){
Log.d("in progress changed", "in if() " + progress);
cView.setCanvasScale(progress);
cView.invalidate();
}
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}});
}
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
Log.d("on touch", "Just touched");
cView.x = (int) event.getX();
cView.y = (int) event.getY();
Log.d("cView x = ", ""+cView.x);
Log.d("cView y = ", ""+cView.y);
cView.invalidate();
return false;
}
}
这是布局 .xml 文件：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/lay_canvas">
<SeekBar
android:id="@+id/sb_activity_layout_canvas"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/button1"
android:layout_alignParentLeft="true"
android:max="10" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/button2"
android:text="Button" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="Button" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_toRightOf="@+id/button2"
android:text="Button" />
<com.anvil.thesis.CustomViewVisual1
android:id="@+id/myView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/sb_activity_layout_canvas"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" />
</RelativeLayout>