在開發過程中有時需要將圖片顯示成圓角圖片,一般我們可以通過在xml中設置drawable shape即可,但今天我給出另一種方法,用java代碼動態去設置圓角,順便做個簡單的筆記。
主要原理是使用系統自帶api:
RoundedBitmapDrawableFactory
簡單的實現類
public class MainActivity extends AppCompatActivity {
private ImageView mImgRectRound;
private ImageView mImgRound;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mImgRectRound = (ImageView) findViewById(R.id.img_rect_rounded);
mImgRound = (ImageView) findViewById(R.id.img_rounded);
rectRoundBitmap();
roundBitmap();
}
private void rectRoundBitmap(){
//得到資源文件的BitMap
Bitmap image= BitmapFactory.decodeResource(getResources(),R.drawable.dog);
//創建RoundedBitmapDrawable對象
RoundedBitmapDrawable roundImg =RoundedBitmapDrawableFactory.create(getResources(),image);
//抗鋸齒
roundImg.setAntiAlias(true);
//設置圓角半徑
roundImg.setCornerRadius(30);
//設置顯示圖片
mImgRectRound.setImageDrawable(roundImg);
}
private void roundBitmap(){
//如果是圓的時候,我們應該把bitmap圖片進行剪切成正方形, 然後再設置圓角半徑爲正方形邊長的一半即可
Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.dog);
Bitmap bitmap = null;
//將長方形圖片裁剪成正方形圖片
if (image.getWidth() == image.getHeight()) {
bitmap = Bitmap.createBitmap(image, image.getWidth() / 2 - image.getHeight() / 2, 0, image.getHeight(), image.getHeight());
} else {
bitmap = Bitmap.createBitmap(image, 0, image.getHeight() / 2 - image.getWidth() / 2, image.getWidth(), image.getWidth());
}
RoundedBitmapDrawable roundedBitmapDrawable = RoundedBitmapDrawableFactory.create(getResources(), bitmap);
//圓角半徑爲正方形邊長的一半
roundedBitmapDrawable.setCornerRadius(bitmap.getWidth() / 2);
//抗鋸齒
roundedBitmapDrawable.setAntiAlias(true);
mImgRound.setImageDrawable(roundedBitmapDrawable);
}
}
佈局文件
<?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.cjl.roundedbitmap.MainActivity">
<ImageView
android:id="@+id/img_rect_rounded"
android:layout_width="200dp"
android:layout_height="300dp"
android:layout_marginTop="20dp"
android:layout_gravity="center_horizontal"/>
<ImageView
android:id="@+id/img_rounded"
android:layout_marginTop="20dp"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_gravity="center_horizontal"/>
</LinearLayout>