Drawable

创建Drawable有三种方式

• 在项目资源中使用图片，res/drawable/下的图片会被自动压缩
• 使用XML文件
• 使用代码构造

LinearLayout mLinearLayout;
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  // Create a LinearLayout in which to add the ImageView
  mLinearLayout = new LinearLayout(this);
  // Instantiate an ImageView and define its properties
  ImageView i = new ImageView(this);
  i.setImageResource(R.drawable.my_image);
  i.setAdjustViewBounds(true); // set the ImageView bounds to match the Drawable's dimensions
  i.setLayoutParams(new Gallery.LayoutParams(LayoutParams.WRAP_CONTENT,
      LayoutParams.WRAP_CONTENT));
  // Add the ImageView to the layout and set the layout as the content view
  mLinearLayout.addView(i);
  setContentView(mLinearLayout);
}

Resources res = mContext.getResources();
Drawable myImage = res.getDrawable(R.drawable.my_image);

Drawable 层次结构