代码实现无xml布局文件对话框

        LinearLayout layout = new LinearLayout(this);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);  //image的布局方式
//    lp.setMargins(10, 10, 10, 10);
        layout.setPadding(60, 60, 60, 20);
        ImageView iv = new ImageView(this);
        iv.setImageResource(R.mipmap.icon_download_qr_code);
        layout.setGravity(Gravity.CENTER);
        iv.setLayoutParams(lp);
        layout.addView(iv);

        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("扫描二维码，下载APP");
        builder.setPositiveButton("其他方式分享", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                Intent intent = new Intent(Intent.ACTION_SEND); // 启动分享发送的属性
                intent.setType("text/plain"); // 分享发送的数据类型
                String msg = "我正在使用《无bugAPP》，挺不错的应用。你也来试试吧！下载地址：https://blog.csdn.com/HardProgrammer";
                intent.putExtra(Intent.EXTRA_TEXT, msg); // 分享的内容
                startActivity(Intent.createChooser(intent, "选择分享"));// 目标应用选择对话框的标题
            }
        });
        builder.setView(layout);
        builder.create().show();