Question

我试图在ImageView的中间画一个圆圈。以下是我的UI代码。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@android:color/white">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_weight="2"
        android:id="@+id/bluh">

        <ImageView
            android:id="@+id/image_background"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_alignParentTop="true"
            android:adjustViewBounds="true"
            android:scaleType="centerCrop"
            android:layout_weight="2"
            android:src="@drawable/hhh" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/l22Parent"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/bluh"
        android:layout_marginTop="10dp"
        android:layout_weight="1"
        android:orientation="horizontal">

        <Button
            android:id="@+id/step18button1"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_below="@+id/step18textView"
            android:layout_marginLeft="3dp"
            android:layout_weight="1"
            android:text="1"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button2"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignTop="@+id/step18button1"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button1"
            android:layout_toRightOf="@+id/step18button1"
            android:layout_weight="1"
            android:text="2"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button3"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button2"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button2"
            android:layout_toRightOf="@+id/step18button2"
            android:layout_weight="1"
            android:text="3"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button4"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button3"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button3"
            android:layout_toRightOf="@+id/step18button3"
            android:layout_weight="1"
            android:text="4"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button5"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button4"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button4"
            android:layout_toRightOf="@+id/step18button4"
            android:layout_weight="1"
            android:text="5"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button6"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button5"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button5"
            android:layout_toRightOf="@+id/step18button5"
            android:layout_weight="1"
            android:text="6"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button7"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button6"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button6"
            android:layout_toRightOf="@+id/step18button6"
            android:layout_weight="1"
            android:text="7"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button8"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button7"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button7"
            android:layout_toRightOf="@+id/step18button7"
            android:layout_weight="1"
            android:text="8"
            android:textSize="13dp" />

        <Button
            android:id="@+id/step18button9"
            style="?android:attr/buttonStyleSmall"
            android:layout_width="39dp"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/step18button8"
            android:layout_marginLeft="3dp"
            android:layout_toEndOf="@+id/step18button8"
            android:layout_toRightOf="@+id/step18button8"
            android:layout_weight="1"
            android:text="9"
            android:textSize="13dp" />
    </LinearLayout>
</LinearLayout>

生成的UI如下所示

下面是我的片段类

/**
 * Created by user on 5/12/2016.
 */
public class GeneralizationFragment extends Fragment {

    Context context;
    private ImageView imageView;
    private int width;
    private int height;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.generalization_fragment, container, false);
        createBitMap(v);

        return v;
    }

    public static GeneralizationFragment newInstance() {

        GeneralizationFragment f = new GeneralizationFragment();
        Bundle b = new Bundle();

        f.setArguments(b);

        return f;
    }


    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        if(isVisibleToUser) {
            Activity a = getActivity();
            if(a != null) a.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        }
    }

    private void createBitMap(final View v) {

        BitmapFactory.Options myOptions = new BitmapFactory.Options();
        myOptions.inDither = true;
        myOptions.inScaled = true;
        myOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;// important
        myOptions.inPurgeable = true;

        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.hhh, myOptions);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setColor(Color.BLUE);


        Bitmap workingBitmap = Bitmap.createBitmap(bitmap);
        Bitmap mutableBitmap = workingBitmap.copy(Bitmap.Config.ARGB_8888, true);



        imageView = (ImageView)v.findViewById(R.id.image_background);

        ViewTreeObserver vto = imageView.getViewTreeObserver();
        vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
            public boolean onPreDraw() {
                imageView.getViewTreeObserver().removeOnPreDrawListener(this);
                height = imageView.getMeasuredHeight();
                width = imageView.getMeasuredWidth();
                Log.d("GENERALIZED", "Width:" + width);

                return true;
            }
        });

        float radius = (float) (width-(width*0.2));

        DisplayMetrics displaymetrics = new DisplayMetrics();
        getActivity().getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        int height = displaymetrics.heightPixels;
        int width = displaymetrics.widthPixels;



        Canvas canvas = new Canvas(mutableBitmap);
        canvas.drawCircle(100, 100, 60, paint);


        imageView.setAdjustViewBounds(true);
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setImageBitmap(mutableBitmap);
    }


}

但是，在我从代码中删除imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);之前，我无法绘制圆圈（或圆圈不可见）。然而，这部分对我来说是一种管理。

我也不知道在中心画画。

无法在ImageView上绘制圆圈

0 个答案: