如何放大/缩小ImageView(不使用画布)android
我正在开发应用程序,在其中我必须旋转,拖放n和放大/缩小图像(较小的一个)到另一个图像(较大的一个)。我已完成旋转并拖动拖放,但无法实现放大/缩小。我知道如何在画布上做,但在我的应用程序中,我没有使用画布。 任何帮助将不胜感激..........如何放大/缩小ImageView(不使用画布)android
感谢 Davender
看看下面的代码,让我知道,如果有帮助。
public class Touch 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();
PointF start = new PointF();
public static PointF mid = new PointF();
// We can be in one of these 3 states
public static final int NONE = 0;
public static final int DRAG = 1;
public static final int ZOOM = 2;
public static int mode = NONE;
float oldDist;
private float[] matrixValues = new float[9];
@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;
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_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;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
}
// Perform the transformation
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
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 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);
}
}
以下是main.xml中的文件
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView
android:id="@+id/imageView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/yourimage"
android:scaleType="matrix">
</ImageView>
</FrameLayout>
更换ImageView的(yourimage)的SRC属性的价值,你在你的项目中有形象的名字。
上面的代码是为我工作。谢谢奥马尔雷曼 – 2011-09-28 13:29:27
嗨什么是间距()我得到了错误的那一行..你能分享它吗? – 2012-12-22 04:17:21
spacing()方法可以在上面的代码中找到它。它计算手指之间的距离。 – 2012-12-23 04:40:56
我很好奇为什么你不能使用画布? – slund 2011-04-25 13:14:24
我是新来的android和不知道如何使用画布完全像如何添加按钮,seekbars等画布。所以我选择了LinearLayout和RelativeLayout来完成这项工作,现在我的应用几乎完成了。缩放是唯一的剩余功能。 – user698425 2011-04-26 04:28:36
我想将它添加到seekbar – user698425 2011-04-26 04:28:52