JHPeng's Blog：宏觀篇。

Intent sharingIntent = new Intent(Intent.ACTION_SEND);
Uri screenshotUri = Uri.parse(path);

sharingIntent.setType("image/png");
sharingIntent.putExtra(Intent.EXTRA_STREAM, screenshotUri);
startActivity(Intent.createChooser(sharingIntent, "Share image using"));

http://sudarmuthu.com/blog/sharing-content-in-android-using-action_send-intent