这是我的java类的代码，其中我绘制了三个塔，我放置了一定数量的环。在onTouchEvent函数中，我注意到activity并相应地增加了移动的数量，而这又是在屏幕上显示的。但是在我进行上一次活动并回来之前，它不会更新。
Number.java
package com.syncnlink.myapplication;
public class Number {
public static int tower1[] = new int[10];
public static int tower2[] = new int[10];
public static int tower3[] = new int[10];
public static void initialize() {
for (int i = 0; i < 10; i++)
{
tower1[i] = i+1;
tower2[i] = -1;
tower3[i] = -1;
}
}
public static int numelements(int arr[]) {
int count = 0;
for (int i = 0; i < 10; i++)
{
if (arr[i] > 0)
count++;
else
continue;
}
return count;
}
public static void setit(int arr[], int a)
{
arr[a]=-1;
}
public static void setit1(int a)
{
tower1[a]=-1;
}
public static boolean isEmpty(int arr[])
{
for(int i=0;i<5;i++)
if(arr[i]>-1)
{
return false;
}
return true;
}
}
NewGame活动
package com.syncnlink.myapplication;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class NewGame extends Activity {
public CustomRectangle cr;
static float x,y,width, height;
public static int moves =0;
private static Bitmap background;
static Canvas canvas;
public int ff=0,initialized=0;
public static int t1,t2,t3;
@Override
protected void onCreate(Bundle savedInstanceState) {
background = BitmapFactory.decodeResource(getResources(),R.drawable.background);
super.onCreate(savedInstanceState);
CustomRectangle cr = new CustomRectangle(this);
setContentView(cr);
Number.initialize();
t1 = Number.numelements(Number.tower1);
t2 = Number.numelements(Number.tower2);
t3 = Number.numelements(Number.tower3);
}
public static class CustomRectangle extends View {
CustomRectangle(Context c) {
super(c);
invalidate();
}
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
NewGame n = new NewGame();
if(n.initialized == 0)
{
Number.initialize();
}
Paint p[]= new Paint[11];
for(int i=0;i<11;i++)
p[i] = new Paint();
p[0].setColor(Color.YELLOW);
p[1].setColor(Color.BLUE);
p[2].setColor(Color.CYAN);
p[3].setColor(Color.RED);
p[4].setColor(Color.GRAY);
p[5].setColor(Color.MAGENTA);
p[6].setColor(Color.BLUE);
p[7].setColor(Color.CYAN);
p[8].setColor(Color.RED);
p[9].setColor(Color.GRAY);
p[10].setColor(Color.MAGENTA);
canvas.drawBitmap(background,0,0,null);
p[0].setStrokeWidth(24);
height = getHeight();
width = getWidth();
float w = width/1794;
float h = height/1008;
canvas.drawLine(100*(width/1794),1000*(height/1008),500*(width/1794),1000*(height/1008),p[0]);
canvas.drawLine(300*(width/1794),1000*(height/1008),300*(width/1794),400,p[0]);
canvas.drawLine((100+600)*(width/1794),1000*(height/1008),(500+600)*(width/1794),1000*(height/1008),p[0]);
canvas.drawLine((300+600)*(width/1794),1000*(height/1008),(300+600)*(width/1794),400*(height/1008),p[0]);
canvas.drawLine((100+1200)*(width/1794),1000*(height/1008),(500+1200)*(width/1794),1000*(height/1008),p[0]);
canvas.drawLine((300+1200)*(width/1794),1000*(height/1008),(300+1200)*(width/1794),400*(height/1008),p[0]);
int j=0;
for (int i = 0; i < 10; i++) {
if(Number.tower1[i]<0)
continue;
else {
canvas.drawRect((150 + (i * 14))*w, (942 - (j * 44))*h, (450 - (i * 14))*w, (987 - (j * 44))*h, p[i + 1]);
j++;
}
}
j=0;
for (int i = 0; i < 10; i++) {
if(Number.tower2[i]<0)
continue;
else {
canvas.drawRect((150 + (i * 14) + 600)*w, (942 - (i * 44))*h, (450 + 600 - (i * 14))*w, (987 - (i * 44))*h, p[i + 1]);
j++;
}
}
j=0;
for (int i = 0; i < 10; i++) {
if(Number.tower3[i]<0)
continue;
else {
canvas.drawRect((150 + 1200 + (i * 14))*w, (942 - (i * 44))*h, (450 + 1200 - (i * 14))*w, (987 - (i * 44))*h, p[i + 1]);
j++;
}
}
p[0].setTextSize(48);
canvas.drawText(" No. of Moves " + moves ,100,40,p[0]);
}
}
@Override
public boolean onTouchEvent( MotionEvent event1) {
try {
switch (event1.getAction()) {
case MotionEvent.ACTION_DOWN: {
x=event1.getX();
y=event1.getY();
if(x<width/3)
{
if(!Number.isEmpty(Number.tower1)) {
Toast.makeText(this, "Pop Tower1 " + t1--, Toast.LENGTH_SHORT).show();
ff=0;
moves++;
Number.setit1(t1);
cr.invalidate();
}
else {
Toast.makeText(this, "Empty! Nothing to Pop", Toast.LENGTH_SHORT).show();
ff = 1;
}
}
else
if(x<width*2/3) {
if (!Number.isEmpty(Number.tower2)) {
Toast.makeText(this, "Pop Tower2 " + t2--, Toast.LENGTH_SHORT).show();
Number.setit(Number.tower2, t2);
ff=0;
moves++;
cr.invalidate();
} else {
ff = 1;
Toast.makeText(this, "Empty! Nothing to Pop", Toast.LENGTH_SHORT).show();
}
}
else
{
if(!Number.isEmpty(Number.tower3)) {
Number.setit(Number.tower3, t3);
Toast.makeText(this, "Pop Tower3 " + t3--, Toast.LENGTH_SHORT).show();
moves++;
cr.invalidate();
ff=0;
}
else {
Toast.makeText(this, "Empty! Nothing to Pop", Toast.LENGTH_SHORT).show();
ff = 1;
}
}
break;
}
case MotionEvent.ACTION_UP: {
x=event1.getX();
y=event1.getY();
if(x<width/3)
{
if(ff==0)
{
Number.setit2(Number.tower1,++t1);
Toast.makeText(this, "Push Tower1 " + t1, Toast.LENGTH_SHORT).show();
}
}
else
if(x<width*2/3)
{
if(ff==0)
{
Number.setit2(Number.tower2,++t2);
Toast.makeText(this, "Push Tower2 " + t2, Toast.LENGTH_SHORT).show();
}
}
else
{
if(ff==0) {
Number.setit2(Number.tower3, ++t3);
Toast.makeText(this, "Push Tower3 " + t3, Toast.LENGTH_SHORT).show();
}
}
break;
}
}
}
catch(Exception e)
{
}
return true;
}
}
所以，我可以在屏幕上看到所有Toasts，如果我在onDraw（）中放了一个toast，我可以看到被多次调用，但是它没有更新信息或者没有重新绘制在前一个上面的新画布。 欢迎任何帮助。现在已经坚持了几天
答案 0 :(得分：0)
我认为您需要在CustomRectangle.class
上创建一些setterpublic void setSomething(Arguments)
{
// do your changes here
invalidate();
}
并调用setter来改变onTounch中绘制的状态。
case:MotionEvent.ACTION_DOWN:
cr.setSomething(Arguments);
....
....
当您调用setter时，他们将在调用invalidate后更新画布的状态。
我希望这可以帮到你！
答案 1 :(得分：0)
您可以通过在构造函数中线程化您的invalidate来修复它，将其修改为：
CustomRectangle(Context c) {
super(c);
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
while(true) {
try {
Thread.sleep(1000);
postInvalidate();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread.start();
}