为什么BitmapFactory.de codeResource缩放图片？ [英] Why does BitmapFactory.decodeResource scale my image?

问题描述

我有一个形象，是120x120px位于我的 / RES /绘制/ 目录。这是必需的所有设备的大小。

I have an image that is 120x120px located in my /res/drawable/ directory. This is the size required for all devices.

要，我现在用的是以下加载此位图：

To load this Bitmap, I am using the following:

Bitmap tmpBmp = BitmapFactory.decodeResource(getResources(), R.drawable.myimage);

问题是，当我衡量 tmpBmp ，大小为360x360px。我知道如何扩大这一回落到我需要的120×120，但它是一种浪费的处理时间，但最小的。

The issue is that when I measure tmpBmp, the size is 360x360px. I know how to scale this back down to the 120x120 that I need, but it is a waste of processing time, although minimal.

我假设，这已经是与屏幕密度，因为我的资源是一个密度较少的目录。

I am assuming that this has something to do with screen densities, since my resource is in a density-less directory.

什么是德codeResource 缩放我的形象的原因？我如何这样做阻止它？

What is the reason for decodeResource scaling my image? And how do I stop it from doing so?

推荐答案

默认绘制目录假定图像需要从默认的比例 MDPI 尺寸。把你的图片在绘制-nodpi 如果要禁用资源扩展。

The default drawable directory assumes that images need to be scaled from the default mdpi size. Put your images in drawable-nodpi if you want to disable resource scaling.

别注意，120x120px图象，如果显示在屏幕上，将3倍小的xxhdpi设备上相比，MDPI装置（如有三倍每英寸为许多像素）。

Do note that a 120x120px image, if displayed on the screen, will be 3x smaller on a xxhdpi device compared to a mdpi device (as there are three times as many pixels per inch).

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