在android中缩放和旋转图像-图像不会出现

Question

I am new to android, and I am having problems making my image appear in my second activity after I use the same scale and rotate code with my first activity. In first activity I am currently retrieving an image from the photo gallery. This image I then display in an ImageView. Before I actually display the image I have to scale the bitmap and then rotate it. This is working - and I got most of the code from this site - thanks! I then save the details of this image to my SQLite database (as in the path name of image on sd card) However, in the second activity - I am then trying to retrieve the image immediately for display in an imageview (from it's pathname - which I have saved to SQLite database), and again I use the same code to scale and rotate the same image to display in this ImageView, however this time, the image does not appear.....? If I just execute the code for scaling the bitmap - the image does appear, but it is only when I try to execute the rotate code that the image won't appear. As said - in first activity - the scale AND rotate works, but for second activity - only the scale works. Here is the code for scaling and rotating

    public static void process (String filePath, ImageView imageView) {

    Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);
    int h = 250;
    int w = 250;
    Bitmap scaled = Bitmap.createScaledBitmap(yourSelectedImage, h, w, true);

    Matrix matrix = new Matrix();
    imageView.setScaleType(ScaleType.MATRIX);
    imageView.setImageBitmap(scaled);
    matrix.postRotate(90f, imageView.getDrawable().getBounds().width()/2,
            imageView.getDrawable().getBounds().height()/2);
    imageView.setImageMatrix(matrix);
}

XML of first activity:

        <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_alignParentTop="true"
        android:layout_marginTop="15dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <ImageView
        android:id="@+id/result"
        android:layout_width="250dip"
        android:layout_height="250dip"
        android:layout_alignParentTop="true"
        android:layout_marginTop="40dp"
        android:contentDescription="@string/desc1"
        android:scaleType="matrix" />

    <Button
        android:id="@+id/selectButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignRight="@+id/textView2"
        android:layout_marginBottom="15dp"
        android:text="Select Photo" />

    <Button
        android:id="@+id/saveButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/selectButton"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="15dp"
        android:layout_marginRight="27dp"
        android:text="Save" />

    <LinearLayout
        android:id="@+id/addbloglinkcontainer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/result" >

        <TextView
            android:id="@+id/addbloglinktext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/add_blog_link" />

        <EditText
            android:id="@+id/blogLink"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="10"
            android:ems="10"
            android:inputType="textUri" />
    </LinearLayout>

</RelativeLayout>

XML of second activity:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_marginTop="15dp"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="250dip"
        android:layout_height="250dip"
        android:layout_alignParentTop="true"
        android:layout_marginTop="40dp"
        android:contentDescription="@string/desc1"
        android:onClick="mthdtocall"
        android:scaleType="matrix" />

</RelativeLayout

Answer 1

Dont know why the image doesnt appear but... You could try to use LRU cache to reuse the same bitmap image in both activities.

developer.android.com/reference/android/util/LruCache.html