android开发文档之resource-drawable用法

Android developer文档中有对resource的drawable进行详细介绍

现在我们就一一介绍：

Bitmap File

A bitmap file is a .png, .jpg, or .gif file. Android creates a Drawable resource for any of these files when you save them in the res/drawable/ directory.

文件路径

res/drawable/filename.png (.png, .jpg, or .gif)
The filename is used as the resource ID.

compiled resource datatype:

Resource pointer to a BitmapDrawable.

引用方式：

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

example:

With an image saved at res/drawable/myimage.png, this layout XML applies the image to a View:

<ImageView    android:layout_height="wrap_content"    android:layout_width="wrap_content"    android:src="@drawable/myimage" />

The following application code retrieves the image as a Drawable:

Resources res = getResources();Drawable drawable = res.getDrawable(R.drawable.myimage);