Android 实现切圆图作为头像使用实例

public class MyView extends View {  Bitmap bmp;  Paint paint = new Paint();  public MyView(Context context) {    super(context);  }  public MyView(Context context, AttributeSet attrs) {    super(context, attrs);    bmp = BitmapFactory.decodeResource(getResources(), R.mipmap.c);    src = new RectF(bmp.getWidth() / 2 - 50, bmp.getHeight() / 2 - 50, bmp.getWidth() / 2 + 50, bmp.getHeight() / 2 + 50);    dst = new Rect(200, 200, 400, 400);    paint.setAntiAlias(true);    paint.setDither(true);    Shader shaer = new BitmapShader(bmp, Shader.TileMode.MIRROR, Shader.TileMode.REPEAT);    paint.setShader(shaer);  }  private RectF src = null;  private Rect dst = null;  @Override  protected void onDraw(Canvas canvas) {    super.onDraw(canvas);    //绘制Bitmap    Matrix m = new Matrix();    //每次set都会重置矩形    m.setRotate(90, bmp.getWidth() / 2, bmp.getHeight() / 2);    m.postTranslate(100, 100);    m.preScale(0.5f, 0.5f, bmp.getWidth() / 2, bmp.getHeight() / 2);    //错切    m.postSkew(0.3f, 0.3f);    // canvas.drawBitmap(bmp, m, null);    // canvas.drawBitmap(bmp, src, dst, null);    //拿view的高宽    canvas.drawArc(src, 100, 270, true, paint);  }}

public class MainActivity extends AppCompatActivity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);  }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:id="@+id/activity_main"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"  tools:context="com.example.administrator.lesson12_drawbitmap.MainActivity">  <com.example.administrator.lesson12_drawbitmap.MyView    android:layout_width="wrap_content"    android:layout_height="wrap_content" /></LinearLayout>