简单实现微信分享（不集成SDK）

//微信的包名
 public static final String PACKAGE_WECHAT = "com.tencent.mm";
    // 判断是否安装指定app
    public static boolean isInstallApp(Context context, String app_package){
        final PackageManager packageManager = context.getPackageManager();
        List<PackageInfo> pInfo = packageManager.getInstalledPackages(0);
        if (pInfo != null) {
            for (int i = 0; i < pInfo.size(); i++) {
                String pn = pInfo.get(i).packageName;
                if (app_package.equals(pn)) {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * 直接分享文本到微信好友
     *
     * @param context 上下文
     */
    public static void shareText2WechatFriend(Context context, String content) {
        if (PlatformUtil.isInstallApp(context, PlatformUtil.PACKAGE_WECHAT)) {
            Intent intent = new Intent();
            ComponentName cop = new ComponentName("com.tencent.mm", "com.tencent.mm.ui.tools.ShareImgUI");
            intent.setComponent(cop);
            intent.setAction(Intent.ACTION_SEND);
            intent.putExtra("android.intent.extra.TEXT", content);
            intent.putExtra("Kdescription", !TextUtils.isEmpty(content) ? content : "");
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(intent);
        } else {
            Toast.makeText(context, "您需要安装微信客户端", Toast.LENGTH_LONG).show();
        }
    }