需要在一个AP里调起其它AP的一个Activity,

比如我这里要调起Browser 的Download Page Activity

    /*
     * This method is called as a result of the user selecting the options menu
     * to see the download window, or when a download changes state. It shows
     * the download window ontop of the current window.
     */
    /* package */void viewDownloads(Uri downloadRecord) {
 
        Context friendContext = null;
        try {
            friendContext = this.createPackageContext("com.android.browser",
                    Context.CONTEXT_IGNORE_SECURITY);
        } catch (NameNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
 
        Intent intent = new Intent();
        intent.setComponent(new ComponentName("com.android.browser",
                "com.android.browser.BrowserDownloadPage"));
        intent.setData(downloadRecord);
        startActivity(intent);
    }