如何将半圆蒙版应用于ImageView [英] How to apply half circle mask to an ImageView

问题描述

我有一个图像，半圆帧图像，我需要将该图像放在此框架内。但是我需要对我的图像应用蒙版，因此它只显示在帧内。

I have an image, a half circle frame image and I need to put that image inside this frame. But I need to apply mask to my image so it is only displayed inside frame.

例如这是我的图像：

我想要的结果应该是这样的：

And my desired result should be like that:

红框也是内部透明的图像视图。

The red frame also an image view which inside is transparent.

如何在Android中实现这一目标？

How can I achieve this in Android?

推荐答案

有一个关于设计Android博客分为四部分，介绍如何实现这一目标。

There's a great tutorial on Styling Android blog in four parts that explains how you can achieve this.

编辑：

我已编辑过c ode在本教程的第二部分中创建了效果：

I've edited the code in part two of the tutorial and created the effect:

private Bitmap processImage(Bitmap bitmap) {
    Bitmap bmp;

    bmp = Bitmap.createBitmap(bitmap.getWidth(),
            bitmap.getHeight(), Bitmap.Config.ARGB_8888);
    BitmapShader shader = new BitmapShader(bitmap,
            BitmapShader.TileMode.CLAMP,
            BitmapShader.TileMode.CLAMP);

    float radius = bitmap.getWidth() / 2f;
    Canvas canvas = new Canvas(bmp);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(shader);

    RectF rect = new RectF(-bitmap.getWidth() / 2f, 0,
            bitmap.getWidth() / 2f, bitmap.getHeight());
    canvas.drawOval(rect, paint);

    return bmp;
}

我刚刚更换了 drawRoundRect 在代码的末尾，带有 drawOval ，它实际上绘制了一个圆圈，其中一半是画布外的。

I just replaced the drawRoundRect at the end of the code with drawOval and it essentially draws a circle that half of it is out of canvas.

这篇关于如何将半圆蒙版应用于ImageView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！