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这里是我想实现放大和缩小的图像的代码。它得到放大，但是当它熄灭屏幕它就会崩溃...还当我缩小图像的尺寸缩小，再后来得到它坠毁。我想限制放大到一个级别，也缩小到原来的位置。放大和缩小
，并继续扩展到屏幕的中间点的图像变化的左上角...
请帮助实现这一....谢谢
package com.imageviewzoomactivity;
import android.app.Activity;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class ImageViewZoomActivityActivity extends Activity implements OnTouchListener {
private static final String TAG = "Touch";
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
Matrix savedMatrix2 = new Matrix();
private static final int WIDTH = 0;
private static final int HEIGHT = 1;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView view = (ImageView) findViewById(R.id.imageView);
view.setOnTouchListener(this);
}
@Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
int rotation = 25;
// Dump touch event to log
dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {
/*case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG");
mode = DRAG;
break;*/
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_UP:
mode = NONE;
Log.d(TAG, "mode=NONE");
savedMatrix.set(matrix);
// matrix.postRotate(90);
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
// ...
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x,
event.getY() - start.y);
}
else if (mode == ZOOM) {
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist/oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN
|| actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid ").append(
action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
}
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
}
sb.append("]");
Log.d(TAG, sb.toString());
}
/** Determine the 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);
}
/** Calculate 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);
}
这是个好主意......但问题是我在写字母泡泡的游戏，画面的左侧部分覆盖上显示的头和屏幕的其他部分有游戏......说寻宝样显示的...现在在游戏画面我要放大和缩小，其具有onsetListener becoz的图像作为气泡会拿出取决于HeadonDisplay文本用户必须选择泡..我希望你能理解我的需要.. .. – user1169079 2012-03-07 05:22:30
我做了使用布局与上面的代码是什么我展示的是最适合我的逻辑... everythig因为我必须承认onDown事件对我的泡沫得到了选择..和我的游戏级别的XML是相对布局 - > 11 ImageViews（第一个图像视图包含背景级图像）我只想缩放ImageVIew或可能缩放背景的相对布局图片 – user1169079 2012-03-07 05:25:08
创建dyna通过扩展View类扩展视图类。当扩展视图类时，您将获得像onDraw（），onTouch（）...这样的覆盖方法，然后使用上面的代码。最后使用layoutid.addView（your_dynamicview）向您的布局添加动态视图。 – 2012-03-07 05:40:25