嗨，我为我的申请画了一幅画布
这是代码我的画布
public class Canvas1 extends View{
int i;
int k;
float l,m;
public Canvas1(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
public Canvas1 (Context context, AttributeSet attrs) {
super(context, attrs);
}
public Canvas1 (Context context, AttributeSet ats, int ds) {
super(context, ats, ds);
}
@Override
public void onDraw(Canvas canvas){
super.onDraw(canvas);
canvas.drawRGB(255, 255, 255);
Paint paint1=new Paint(Color.BLACK);
Paint paint=new Paint(200);
paint.setStrokeWidth((float)0.5);
canvas.drawLine(0,0,0,getMeasuredHeight(), paint1);
canvas.drawLine(0,0, getMeasuredWidth(), 0, paint1);
canvas.drawLine(0,getMeasuredHeight(), getMeasuredWidth(),getMeasuredHeight(), paint1);
canvas.drawLine(getMeasuredWidth(),getMeasuredHeight(), getMeasuredWidth(), 0, paint1);
//canvas.drawLine(0, 0, ((float)getMeasuredWidth()), ((float)getMeasuredHeight()), paint);
if(l!=0||m!=0)
{
canvas.drawLine(getMeasuredWidth()/2,getMeasuredHeight()/2,getMeasuredWidth()/2,getMeasuredHeight(),paint);
canvas.drawLine(0,0,getMeasuredWidth()/2,getMeasuredHeight()/2,paint);
}
for(int i=1;i<5;i++)
canvas.drawLine(((float)getMeasuredWidth())/5*i, 0, ((float)getMeasuredWidth()/5*i),getMeasuredHeight(), paint);
for(int i=0;i<5;i++)
canvas.drawLine(0, getMeasuredHeight()/5*i, getMeasuredWidth(), getMeasuredHeight()/5*i, paint);
canvas.save();
}
public Boolean setline(float d,float e){
l=d;
m=e;
Log.i("Hello Canvas",l+" "+m+" ");
return true;
}
}
现在我试图从我的主活动中调用函数setline（），在这个活动中有一个画布数组。这是我活动的代码
public class HelloCanvasActivity extends Activity {
/** Called when the activity is first created. */
Integer[] in={R.id.can1,R.id.can2,R.id.can3,R.id.can4,R.id.can5,R.id.can6,R.id.can7,R.id.can8};
float x,y;
int j=0;
Canvas1[] can=new Canvas1[8];
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
for(int i=0;i<8;i++)
{
can[i]=(Canvas1)findViewById(in[i]);
}
can[0].setline((float)0.5,(float) 0.5);
new Thread(new Runnable(){
public void run(){
for(int i=0;i<8;i++){
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
can[i].setline((float)0.5,(float)0.5);
}
}
}).start();
}
}
当我忽略线程时，代码行中的sleep（1000）正在绘制，但是当我放置线程时，sleep（1000）setline在1秒后调用，我正在hello world的日志表中获取日志，但是没有行在画布上绘制，请帮助我找到错误的地方。
最佳答案
在setline方法中，调用invalidate()