android 应用实现微信好友或朋友圈分享

// 微信注册初始化  
api = WXAPIFactory.createWXAPI(this, "wx5ce2ffa100e3f587", true);  
api.registerApp("wx5ce2ffa100e3f587");  

private void share2weixin(int flag) {  
    // Bitmap bmp = BitmapFactory.decodeResource(getResources(),  
    // R.drawable.weixin_share);  
  
    if (!api.isWXAppInstalled()) {  
        Toast.makeText(WXEntryActivity.this, "您还未安装微信客户端",  
                Toast.LENGTH_SHORT).show();  
        return;  
    }  
  
    WXWebpageObject webpage = new WXWebpageObject();  
    webpage.webpageUrl = "http://baidu.com";  
    WXMediaMessage msg = new WXMediaMessage(webpage);  
  
    msg.title = "title";  
    msg.description = getResources().getString(  
            R.string.app_share_weixin_txt);  
    Bitmap thumb = BitmapFactory.decodeResource(getResources(),  
            R.drawable.weixin_share);  
    msg.setThumbImage(thumb);  
    SendMessageToWX.Req req = new SendMessageToWX.Req();  
    req.transaction = String.valueOf(System.currentTimeMillis());  
    req.message = msg;  
    req.scene = flag;  
    api.sendReq(req);  
}