Blurred 1dip shape lines (borders) on Android

问题:

Here is the screenshot from my app:

It's taken from Samsung Galaxy Note 10.1 (mdpi 149 ppi).

My client thinks that the border line around bottom buttons and rounded rectangle above are blurred.

I'm using shape as a background which looks like this:

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"
    >
    <corners
        android:radius="8dp" />

    <stroke android:width="1dp" android:color="@color/dark_gray" />

    <solid android:color="@color/sepia_bright" />

</shape>

When I use simple view as a line with 1dp height like this:

<View
    android:background="@color/bright_gray"
    android:layout_width="match_parent"
    android:layout_height="1dp" />

It's perfectly sharp as you can see on next screenshot:

Simple horizontal lines are ok, but rectangle around graph is blurred again.

What am I doing wrong?

Thanks for any help.

回答1:

My first guess would be that this is a problem with bi-linear filtration (http://en.wikipedia.org/wiki/Bilinear_filtering).

To fix it, see The View#setLayerType method.

I had an issue with this in a custom view. Inside my view's init method, I have the following code:

    if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB){
        this.setLayerType(View.LAYER_TYPE_SOFTWARE, null);          
    }

This fixed my issue, but you could do the same thing using the android:layerType xml attribute, or the setLayerType method in code on your view.