如何使表面视图透明

大家好，我想让我的绘图表面视图透明。我尝试了很多东西，但它不工作。

下面是使表面视图透明的 xml 代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >


<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent" >


<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/icon" >
</ImageView>


<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#00000000" >


<codewalla.android.drawings.DrawingSurface
android:id="@+id/drawingSurface"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
</codewalla.android.drawings.DrawingSurface>
</LinearLayout>
</FrameLayout>


<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >


<Button
android:id="@+id/colorRedBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="10"
android:onClick="onClick"
android:text="R" />


<Button
android:id="@+id/colorBlueBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="10"
android:onClick="onClick"
android:text="G" />


<Button
android:id="@+id/colorGreenBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="10"
android:onClick="onClick"
android:text="B" />


<Button
android:id="@+id/undoBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="10"
android:onClick="onClick"
android:text="U" />


<Button
android:id="@+id/redoBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="10"
android:onClick="onClick"
android:text="R" />
</LinearLayout>


</RelativeLayout>

63731

小开

Is your DrawingSurface and extension of SurfaceView?

There is no way to get a SurfaceView to do what you are wanting it to do. The mechanics of the surface view are such that it can not have anything visible behind it. (see the answer here http://groups.google.com/group/android-developers/browse_thread/thread/8d88ef9bb22da574)

I tested your hierarchy with a custom view extending SurfaceView and I see your problem. If I switch to a custom view that simply extends View, I can get transparency.

小开

最佳答案

Try this in the constructor:

SurfaceView sfvTrack = (SurfaceView)findViewById(R.id.sfvTrack);
sfvTrack.setZOrderOnTop(true);    // necessary
SurfaceHolder sfhTrackHolder = sfvTrack.getHolder();
sfhTrackHolder.setFormat(PixelFormat.TRANSPARENT);

小开

TexttureView will be better for your needs than SurfaceView, i believe.

小开

sfvTrack.setZOrderOnTop(true);

will place the surfaceView on top of the window, meaning you cannot add items on top of the surfaceView.

If you want to add views on top of the surface view; you should consider using:

setZOrderMediaOverlay(true);

instead. This places this surfaceView on top of other surfaceViews, but still behind the window, allowing you to add other visible views on top of the surface view.