如何在Android中将图像从左到右从右向左移动？
问题描述：
我是Android新手。我想从左到右，从右到左移动图像。当用户触摸图像的右侧图像时，它会向右侧移动。当用户触摸图像的右侧时，会发生一些事情。但图像将移动预定义点横跨x轴。如何在Android中将图像从左到右从右向左移动？
例如：图像将依次移动这些点上的p1（100,100），p2（150,100），p3（200,100），p4（250,100）。如果用户触摸p1的左侧，它将保持当前位置。在p4将发生所有事情。我可以将图像从p1移动到p2，将p2移动到p1。当我添加p3和p4时，它不像我预期的那样工作。
这是我的GameView类。
public class GameView extends SurfaceView{
private Bitmap BG_image;
private SurfaceHolder holder;
//private GameLoopThread gameLoopThread;
int x;
int y;
private int srcX=100;
private int srcY=100;
int replaceX=0,areaThreshold=50;
int distance=50;
public GameView(Context context) {
super(context);
//gameLoopThread = new GameLoopThread(this);
holder = getHolder();
holder.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
/* boolean retry = true;
gameLoopThread.setRunning(false);
while (retry) {
try {
gameLoopThread.join();
retry = false;
} catch (InterruptedException e) {
}
}*/
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
/* gameLoopThread.setRunning(true);
gameLoopThread.start();*/
Canvas c = holder.lockCanvas(null);
onDraw(c);
holder.unlockCanvasAndPost(c);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
});
BG_image = BitmapFactory.decodeResource(getResources(), R.drawable.icon);
Bitmap.createScaledBitmap(BG_image, BG_image.getWidth(), BG_image.getHeight(), false);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// TODO Auto-generated method stub
// x = (int) ev.getX();
// y = (int) ev.getY();
updateX(srcX);
replaceX=(int)ev.getX();
int StartX=0, EndX=0;
StartX=replaceX-areaThreshold;
EndX=replaceX+areaThreshold;
if(StartX<=100){
SurfaceHolder holder=getHolder();
Canvas myCanvas=holder.lockCanvas(null);
onDraw(myCanvas);
holder.unlockCanvasAndPost(myCanvas);
srcX=100;
}
else if(StartX>100 && StartX<250){
SurfaceHolder holder=getHolder();
Canvas myCanvas=holder.lockCanvas(null);
onDraw(myCanvas);
holder.unlockCanvasAndPost(myCanvas);
srcX=srcX+distance;
}
if(EndX>100 && EndX<250){
SurfaceHolder holder=getHolder();
Canvas myCanvas=holder.lockCanvas(null);
onDraw(myCanvas);
holder.unlockCanvasAndPost(myCanvas);
srcX=srcX-distance;
}
else if(EndX>250){
SurfaceHolder holder=getHolder();
Canvas myCanvas=holder.lockCanvas(null);
onDraw(myCanvas);
holder.unlockCanvasAndPost(myCanvas);
srcX=250;
}
return super.onTouchEvent(ev);
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
updateX(srcX);
Paint paint = new Paint();
canvas.drawColor(Color.BLACK);
canvas.drawRect(new Rect(0,0,getWidth(),getHeight()),paint);
canvas.drawBitmap(BG_image, srcX, srcY, null);
}
private int updateX(int srcX){
this.srcX =srcX;
return srcX ;
}
}
请仔细阅读我的代码，给你解决我的问题提宝贵意见。 希望我会尽快回复！
答
现在，我明白我的问题。非常感谢您提出您的建议。 这是我更新的代码。
public class GameView extends SurfaceView{
private Bitmap BG_image;
private SurfaceHolder holder;
int x=100;
private int srcX=100;
private int srcY=100;
int distance=50;
public GameView(Context context) {
super(context);
holder = getHolder();
holder.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
Canvas c = holder.lockCanvas(null);
onDraw(c);
holder.unlockCanvasAndPost(c);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
});
BG_image = BitmapFactory.decodeResource(getResources(), R.drawable.icon);
Bitmap.createScaledBitmap(BG_image, BG_image.getWidth(), BG_image.getHeight(), false);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// TODO Auto-generated method stub
x = (int) ev.getX();
if(x-srcX>0)
srcX += distance;
else if(x-srcX<0)
srcX -= distance;
if(srcX<=100)
srcX = 100;
else if(srcX>250)
srcX = 250;
Log.w("ev.getX : srcX",x+" : "+srcX);
SurfaceHolder holder=getHolder();
Canvas myCanvas=holder.lockCanvas(null);
onDraw(myCanvas);
holder.unlockCanvasAndPost(myCanvas);
return super.onTouchEvent(ev);
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
Paint paint = new Paint();
canvas.drawColor(Color.BLACK);
canvas.drawRect(new Rect(0,0,getWidth(),getHeight()),paint);
canvas.drawBitmap(BG_image, srcX-BG_image.getWidth()/2, srcY, null);
}
}
答
这是很容易与Android TranslateAnimation
ImageView img_animation = (ImageView) findViewById(R.id.img_animation);
TranslateAnimation animation = new TranslateAnimation(0.0f, 400.0f,
0.0f, 0.0f); // new TranslateAnimation(xFrom,xTo, yFrom,yTo)
animation.setDuration(5000); // animation duration
animation.setRepeatCount(5); // animation repeat count
animation.setRepeatMode(2); // repeat animation (left to right, right to left)
//animation.setFillAfter(true);
img_animation.startAnimation(animation); // start animation
找到这里move an image from left to right and right to left in android
您的代码注释掉和混乱，你的解释有逻辑上的缺陷的详细信息。你可以做得更好。 – Anko 2011-06-18 12:46:35
同意Aku。另外，你不应该直接调用'onDraw'，你应该设置srcX值并调用'invalidate'，它告诉系统安排一次调用'onDraw'。而'updateX'方法似乎没有任何用途。我认为你可以在这里消除大约一半的代码。 – DocDude 2011-06-21 17:32:25