我正在尝试使用图像背景和文本视图等小部件来缩放布局。我已经通过搜索和遵循一些教程实现了捏缩放。但问题是缩放布局时不平滑（闪烁）。
那么有没有人有关于这个问题的解决方案？或者有不同的方法如何平滑地缩放布局？
任何想法将不胜感激。
这是我的代码：
public class ZoomActivity extends Activity {
View mainView = null;
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
PointF oldDistPoint = new PointF();
public static String TAG = "ZOOM";
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.landingpage);
mainView = (LinearLayout) findViewById(R.id.linear);
mainView.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
Log.d(TAG, "mode=DRAG");
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG");
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
oldDistPoint = spacingPoint(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 10f) {
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
System.out.println("current time :"
+ System.currentTimeMillis());
break;// return !gestureDetector.onTouchEvent(event);
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
Log.d(TAG, "mode=NONE");
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
} else if (mode == ZOOM) {
PointF newDist = spacingPoint(event);
float newD = spacing(event);
Log.e(TAG, "newDist=" + newDist);
float[] old = new float[9];
float[] newm = new float[9];
Log.e(TAG, "x=" + old[0] + ":&:" + old[2]);
Log.e(TAG, "y=" + old[4] + ":&:" + old[5]);
float scale = newD / oldDist;
float scalex = newDist.x / oldDistPoint.x;
float scaley = newDist.y / oldDistPoint.y;
zoom(scale, scale, start);
}
break;
}
return true;
}
});
}
/**
* zooming is done from here
*/
public void zoom(Float scaleX, Float scaleY, PointF pivot) {
mainView.setPivotX(pivot.x);
mainView.setPivotY(pivot.y);
mainView.setScaleX(scaleX);
mainView.setScaleY(scaleY);
}
/**
* space between the first two fingers
*/
private float spacing(MotionEvent event) {
// ...
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
private PointF spacingPoint(MotionEvent event) {
PointF f = new PointF();
f.x = event.getX(0) - event.getX(1);
f.y = event.getY(0) - event.getY(1);
return f;
}
/**
* the mid point of the first two fingers
*/
private void midPoint(PointF point, MotionEvent event) {
// ...
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
}