如何在Android的操作栏中显示圆形徽标？

Question

就像上面的Google Plus屏幕截图一样,我想在操作栏中显示一个圆形的头像图像.我该怎么办？

Answer 1

您可以使用位图以编程方式执行此操作:

首先在你的活动的onCreate()上做这个:

getSupportActionBar().setDisplayShowHomeEnabled(true);
Drawable drawable = new BitmapDrawable(getResources(), createCircleBitmap(sourceBitmap));
getSupportActionBar().setIcon(drawable);

这是createCircleBitmap()方法:

public Bitmap createCircleBitmap(Bitmap bitmapimg){
        Bitmap output = Bitmap.createBitmap(bitmapimg.getWidth(),
                bitmapimg.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmapimg.getWidth(),
                bitmapimg.getHeight());

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawCircle(bitmapimg.getWidth() / 2,
                bitmapimg.getHeight() / 2, bitmapimg.getWidth() / 2, paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmapimg, rect, rect, paint);
        return output;
    }

PS:如果您没有Bitmap,可以使用它将Drawable转换为Bitmap:

Bitmap sourceBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.your_drawable);

Answer 2

1. 创建圆形图像视图.
2. 使用圆形图像视图为操作栏创建自定义视图
3. 将视图膨胀并将自定义视图显示为操作栏.

<RelativeLayout         xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="@drawable/black_pattern" >

<TextView
 android:id="@+id/title_text"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_centerInParent="true"
 android:textAllCaps="true"
 android:textAppearance="?android:attr/textAppearanceLarge"
 android:textColor="#fff"
 android:textStyle="bold" />

<com.example.CircularImageView
 android:id="@+id/circularimageView1"
 android:layout_width="35dp"
 android:layout_height="35dp"
 android:layout_alignParentLeft="true"
 android:layout_centerVertical="true"
 android:layout_marginLeft="8dp"/>

</RelativeLayout> 

Activity.java

ActionBar mActionBar = getActionBar();
mActionBar.setDisplayShowHomeEnabled(false);
mActionBar.setDisplayShowTitleEnabled(false);
LayoutInflater mInflater = LayoutInflater.from(this);

View mCustomView = mInflater.inflate(R.layout.actionbar, null);

mActionBar.setCustomView(mCustomView);
mActionBar.setDisplayShowCustomEnabled(true);