仅在父视图外部缩放图像视图和底部剪辑

Question

如何缩放 ImageView，但当它/部分位于其父视图之外时，仍然让它剪辑(仅底部(？

我的代码;

XML 有 3 个元素;原始大小的图像，视图高 200 像素，视图高 150 像素。

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="1000px"
android:layout_height="850px"
android:background="#FFFEC6"
android:orientation="vertical">
<!-- single image in raw size -->
<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/fauxcard"
    />
<!-- should be SCALED with NO CLIPPING -->
<RelativeLayout
    android:id="@+id/Wrapper1"
    android:layout_width="1000px"
    android:layout_height="200px"
    android:background="#cccccc">
</RelativeLayout>
<!-- should be SCALED with the BOTTOM CLIPPED -->
<RelativeLayout
    android:id="@+id/Wrapper2"
    android:layout_width="1000px"
    android:layout_height="150px"
    android:background="#C6FFD1"
    android:clipChildren="true">
</RelativeLayout>
</LinearLayout>

.java;

    RelativeLayout r1 = (RelativeLayout) findViewById(R.id.Wrapper1);
    RelativeLayout r2 = (RelativeLayout) findViewById(R.id.Wrapper2);
    int marginLeft = 0;
    for (int i = 0; i < 10; i++)
    {
        // IV 1 - the parent view for these is the correct 200 high, so these will be unclipped/unscaled
        ImageView myImg1 = new ImageView(this);
        myImg1.setImageResource(R.drawable.fauxcard);
        RelativeLayout.LayoutParams layout1 = new RelativeLayout.LayoutParams(100, 200);
        layout1.setMargins(marginLeft, 0, 0, 0);
        r1.addView(myImg1, layout1);
        // IV 2 - the parent view for these is NOT high enough (only 150 high), so I want these SCALED but CLIPPED (bottom of image clipped)
        ImageView myImg2 = new ImageView(this);
        myImg2.setImageResource(R.drawable.fauxcard);
        // scaling
        // myImg2.setScaleType(ImageView.ScaleType.CENTER); // NOT scaled - clipped
        // myImg2.setScaleType(ImageView.ScaleType.CENTER_INSIDE); //  scaled - NOT clipped
        myImg2.setScaleType(ImageView.ScaleType.CENTER_CROP); // scaled - clipped at TOP and bottom
        // myImg2.setScaleType(ImageView.ScaleType.FIT_END); // scaled TOO MUCH - clip not needed
        // myImg2.setScaleType(ImageView.ScaleType.FIT_START); // scaled TOO MUCH - clip not needed
        // myImg2.setScaleType(ImageView.ScaleType.FIT_CENTER); // scaled TOO MUCH - clip not needed
        // myImg2.setScaleType(ImageView.ScaleType.FIT_XY); // scaled incorrect ratio - clip not needed
        // myImg2.setScaleType(ImageView.ScaleType.MATRIX); // NOT scaled - clipped
        RelativeLayout.LayoutParams layout2 = new RelativeLayout.LayoutParams(100, 200);
        layout2.setMargins(marginLeft, 0, 0, 0);
        r2.addView(myImg2, layout2);
        // I am using marginLeft as my real scenario is more complex - there are varying gaps between the images based on other logic
        // the important issue is CLIPPING the images whilst scaling them
        marginLeft += 100;
    }

对于这两个相对布局，我添加了 10 张图像。我希望两组图像的比例相同，但由于第二个 RL 不够高，我希望剪切这些图像(图像底部消失(。

我已经尝试了所有ScaleType，但没有一个能做到这一点。最接近的是CENTER_CROP，它具有正确的缩放比例，但顶部和底部都被剪裁了(同样，我只想剪裁底部(。

这是一张图片;https://imgur.com/a/QLJkm

Answer 1

将此代码放在ViewTreeObserver 中，或者您可以自定义图像视图

    Matrix matrix = imageView.getImageMatrix();
    float scale;
    final int viewWidth = getWidth() - getPaddingLeft() - getPaddingRight();
    final int drawableWidth = drawable.getIntrinsicWidth();
    scale = (float) viewWidth / (float) drawableWidth;
    matrix.setScale(scale, scale);
    setImageMatrix(matrix);