更改背景图片但保持视图可绘制 android xml

Question

我有一个 Framelayout，它有一些圆角通过可绘制 xml 文件

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle" >

    <!-- View background color -->
    <solid
            android:color="@color/colorPrimary" >
    </solid>

    <!-- The radius makes the corners rounded -->
    <corners
        android:topLeftRadius="20dp"
        android:bottomRightRadius="20dp" >
    </corners>
</shape>

在 FrameLayout 中，我有 2 个 TextView 和一个以编程方式加载位图的 imageView。问题是我已尽一切努力为 ImageView 提供与 FrameLayout 相同的圆角，因此我决定用另一个简单的视图（如 FrameLayout 或 smth）替换 ImageView 并将位图图像设置为视图的背景。这也没有用。

那么在视图中是否有任何方法可以在 xml 中设置带角的可绘制对象，并且稍后以编程方式使用位图更改背景以在加载新图像时以某种方式保持圆角？谢谢

Answer 1

您可以使用库轻松实现它。但是还有另一种方法。您可以在 CardView 中使用您的图像。当您设置 cardCornerRadius 功能时，覆盖 cardview 角的图像角也会变圆。

或者试试这个

    ImageView yourImageView = findViewById(R.id.yourImageView);

    Bitmap bitmap =((BitmapDrawable) ResourcesCompat.getDrawable(R.drawable.anyPicture)).getBitmap();
    Bitmap roundedImageBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
    Canvas canvas=new Canvas(roundedImageBitmap);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
    canvas.drawRoundRect((new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight())), 100, 100, paint); // You can adjust the roundness here

    yourimageView.setImageBitmap(roundedImageBitmap);

Answer 2

解决方案

步骤 1. 转到 res/values 文件夹，创建一个名为 attrs.xml

的 xml 文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="RoundedImageView">
        <attr name="topLeftCorner" format="dimension" />
        <attr name="topRightCorner" format="dimension" />
        <attr name="bottomRightCorner" format="dimension" />
        <attr name="bottomLeftCorner" format="dimension" />
    </declare-styleable>
</resources>

第 2 步。 创建一个从 AppCompatImageView 扩展的 class，命名为 RoundedImageView

public class RoundedImageView extends AppCompatImageView {

    private final Path path = new Path();
    private final float[] radii = new float[8];
    private final RectF rect = new RectF();

    public RoundedImageView(@NonNull Context context) {
        this(context, null);
    }

    public RoundedImageView(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundedImageView);
        try {
            int topLeftCorner = a.getDimensionPixelSize(R.styleable.RoundedImageView_topLeftCorner, 0);
            int topRightCorner = a.getDimensionPixelSize(R.styleable.RoundedImageView_topRightCorner, 0);
            int bottomRightCorner = a.getDimensionPixelSize(R.styleable.RoundedImageView_bottomRightCorner, 0);
            int bottomLeftCorner = a.getDimensionPixelSize(R.styleable.RoundedImageView_bottomLeftCorner, 0);
            radii[0] = topLeftCorner;
            radii[1] = topLeftCorner;
            radii[2] = topRightCorner;
            radii[3] = topRightCorner;
            radii[4] = bottomRightCorner;
            radii[5] = bottomRightCorner;
            radii[6] = bottomLeftCorner;
            radii[7] = bottomLeftCorner;
        } finally {
            a.recycle();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        rect.left = 0;
        rect.top = 0;
        rect.right = getWidth();
        rect.bottom = getHeight();
        path.rewind();
        path.addRoundRect(rect, radii, Path.Direction.CW);
        canvas.clipPath(path);
        super.onDraw(canvas);
    }
}

步骤 3. 从布局文件中使用它。

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#F00"
    android:gravity="center">

    <com.example.roundedimageview.RoundedImageView
        android:id="@+id/imageView"
        android:layout_width="240dp"
        android:layout_height="240dp"
        android:layout_gravity="center"
        android:scaleType="centerCrop"
        android:src="@drawable/ic_android"
        app:bottomRightCorner="20dp"
        app:topLeftCorner="20dp" />
</FrameLayout>

结果

好处

您可以设置左上角、右上角、右下角、左下角的圆角半径。
使用 Glide、Picasso 库

限制

ScaleType is either CENTER_CROP or FIT_XY

更改背景图片但保持视图可绘制 android xml

Change background image but keep drawable to a view android xml

android

imageview

android-drawable

android-bitmap

android-framelayout