Question

我有SurfaceView，我希望Bitmap Logo内的canvas可以移动

我做错了什么？

static float x, y;
Bitmap logo;

SurfaceView ss = (SurfaceView) findViewById(R.id.svSS);   
    logo = BitmapFactory.decodeResource(getResources(), R.drawable.logo);

    x = 40;
    y = 415;
    ss.setOnTouchListener(new View.OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent me) {
            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        switch(me.getAction()) {
        case MotionEvent.ACTION_DOWN:
            x = me.getX();
            y = me.getY();
            break;
        case MotionEvent.ACTION_UP:
            x = me.getX();
            y = me.getY();
            break;
        case MotionEvent.ACTION_MOVE:
            x = me.getX();
            y = me.getY();
            break;
            }
        return true;
        }
    });

public class OurView extends SurfaceView implements Runnable{

    Thread t = null;
    SurfaceHolder holder;
    boolean isItOK = false;


    public OurView(Context context) {
        super(context);
        holder = getHolder();

    }
    public void run (){
        while (isItOK == true){
            //canvas DRAWING
            if (!holder.getSurface().isValid()){
                continue;
            }
            Canvas c = holder.lockCanvas();
            c.drawARGB(255, 200, 100, 100);
            c.drawBitmap(logo, x,y,null);
            holder.unlockCanvasAndPost(c);
        }
    }
    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();

    }
}

现在表面视图只是黑色..没有任何反应也没有发生颜色200, 100, 100

Answer 1

您可能忘记在onDraw(Canvas c)课程中实施OurView方法，并将onTouchEvent移到课堂内。

类结构应该是这样的：

public class OurView extends View implements Runnable {

//...your runnable stuff here
//...Runnable stuff means your run(), pause() etc.

  public OurView(Context context) {
    super(context);
    //your constructor stuff here
    // your constructor, do you find the similar stuff to this you wrote? That's your constructor, so you can just add:
    holder = getHolder();
}

protected void onDraw (Canvas c) {

    c.drawBitmap(bitmap, x, y);
//set colour, draw bitmap here, onDraw() will be called automatically, so just call invalidate(); when you need to "refresh" the view
}

public boolean onTouchEvent(MotionEvent e) {
    float x = e.getX();
    float y = e.getY();

    swith(e.getAction()) {
    case MotionEvent.ACTION_DOWN:
     ...
    }
}
}

有关更明确的示例和参考，请转到：

Implementing a Custom View

Custom Components

希望它可以帮助你。

用于移动位图的“曲面”视图和画布

1 个答案: