此代码加载图片并将其放入 imageView 中，然后您可以使用画布在图像上绘制矩形。imageView 有两种，一种用于加载图像，另一种用于在此上绘制矩形。我需要同时在图像和绘图中缩放和平移（用两个手指），有人可以帮我吗？
public class MainActivity extends Activity
{
Button btnLoadImage;
TextView textSource;
ImageView imageResult, imageDrawingPane;
final int RQS_IMAGE1 = 1;
Uri source;
Bitmap bitmapMaster;
Canvas canvasMaster;
Bitmap bitmapDrawingPane;
Canvas canvasDrawingPane;
projectPt startPt;
@Override
protected void onCreate (Bundle savedInstanceState)
{
super.onCreate (savedInstanceState);
setContentView (R.layout.activity_main);
btnLoadImage = (Button) findViewById (R.id.loadimage);
textSource = (TextView) findViewById (R.id.sourceuri);
imageResult = (ImageView) findViewById (R.id.result);
imageDrawingPane = (ImageView) findViewById (R.id.drawingpane);
btnLoadImage.setOnClickListener (new OnClickListener ()
{
@Override
public void onClick (View arg0)
{
Intent intent = new Intent (Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult (intent, RQS_IMAGE1);
}
});
imageResult.setOnTouchListener (new OnTouchListener ()
{
@Override
public boolean onTouch (View v, MotionEvent event)
{
int action = event.getAction ();
int x = (int) event.getX ();
int y = (int) event.getY ();
switch (action)
{
case MotionEvent.ACTION_DOWN:
textSource.setText ("ACTION_DOWN- " + x + " : " + y);
startPt = projectXY ((ImageView) v, bitmapMaster, x, y);
break;
case MotionEvent.ACTION_MOVE:
textSource.setText ("ACTION_MOVE- " + x + " : " + y);
drawOnRectProjectedBitMap ((ImageView) v, bitmapMaster, x, y);
break;
case MotionEvent.ACTION_UP:
textSource.setText ("ACTION_UP- " + x + " : " + y);
drawOnRectProjectedBitMap ((ImageView) v, bitmapMaster, x, y);
finalizeDrawing ();
break;
}
/*
* Return 'true' to indicate that the event have been consumed.
* If auto-generated 'false', your code can detect ACTION_DOWN only,
* cannot detect ACTION_MOVE and ACTION_UP.
*/
return true;
}
});
}
class projectPt
{
int x;
int y;
projectPt (int tx, int ty)
{
x = tx;
y = ty;
}
}
private projectPt projectXY (ImageView iv, Bitmap bm, int x, int y)
{
if (x < 0 || y < 0 || x > iv.getWidth () || y > iv.getHeight ())
{
//outside ImageView
return null;
} else
{
int projectedX = (int) ((double) x * ((double) bm.getWidth () / (double) iv.getWidth ()));
int projectedY = (int) ((double) y * ((double) bm.getHeight () / (double) iv.getHeight ()));
return new projectPt (projectedX, projectedY);
}
}
private void drawOnRectProjectedBitMap (ImageView iv, Bitmap bm, int x, int y)
{
if (x < 0 || y < 0 || x > iv.getWidth () || y > iv.getHeight ())
{
//outside ImageView
return;
} else
{
int projectedX = (int) ((double) x * ((double) bm.getWidth () / (double) iv.getWidth ()));
int projectedY = (int) ((double) y * ((double) bm.getHeight () / (double) iv.getHeight ()));
//clear canvasDrawingPane
canvasDrawingPane.drawColor (Color.TRANSPARENT, Mode.CLEAR);
Paint paint = new Paint ();
paint.setStyle (Paint.Style.STROKE);
paint.setColor (Color.WHITE);
paint.setStrokeWidth (3);
canvasDrawingPane.drawRect (startPt.x, startPt.y, projectedX, projectedY, paint);
imageDrawingPane.invalidate ();
textSource.setText (x + ":" + y + "/" + iv.getWidth () + " : " + iv.getHeight () + "\n" +
projectedX + " : " + projectedY + "/" + bm.getWidth () + " : " + bm.getHeight ());
}
}
private void finalizeDrawing ()
{
canvasMaster.drawBitmap (bitmapDrawingPane, 0, 0, null);
}
@Override
protected void onActivityResult (int requestCode, int resultCode, Intent data)
{
super.onActivityResult (requestCode, resultCode, data);
Bitmap tempBitmap;
if (resultCode == RESULT_OK)
{
switch (requestCode)
{
case RQS_IMAGE1:
source = data.getData ();
textSource.setText (source.toString ());
try
{
//tempBitmap is Immutable bitmap,
//cannot be passed to Canvas constructor
tempBitmap = BitmapFactory.decodeStream (getContentResolver ().openInputStream (source));
Config config;
if (tempBitmap.getConfig () != null)
{
config = tempBitmap.getConfig ();
} else
{
config = Config.ARGB_8888;
}
//bitmapMaster is Mutable bitmap
bitmapMaster = Bitmap.createBitmap (tempBitmap.getWidth (), tempBitmap.getHeight (), config);
canvasMaster = new Canvas (bitmapMaster);
canvasMaster.drawBitmap (tempBitmap, 0, 0, null);
imageResult.setImageBitmap (bitmapMaster);
//Create bitmap of same size for drawing
bitmapDrawingPane = Bitmap.createBitmap (tempBitmap.getWidth (), tempBitmap.getHeight (), config);
canvasDrawingPane = new Canvas (bitmapDrawingPane);
imageDrawingPane.setImageBitmap (bitmapDrawingPane);
} catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace ();
}
break;
}
}
}
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<Button
android:id="@+id/loadimage"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Load Image 1" />
<TextView
android:id="@+id/sourceuri"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="@+id/result"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:background="@android:color/background_dark"
android:scaleType="centerInside" />
<ImageView
android:id="@+id/drawingpane"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="centerInside"
android:layout_alignLeft="@id/result"
android:layout_alignTop="@id/result"
android:layout_alignRight="@id/result"
android:layout_alignBottom="@id/result"/>
</RelativeLayout>
</LinearLayout>