安卓开发设置dialog长宽并去掉标题

1.编写布局文件qr_alert.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    >

    <ImageView
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:id="@+id/qralertImageView1"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/qralertTextView1"
        android:text="http://127.0.0.1:8080"/>

</LinearLayout>

2.MainActivity.class里写入代码

//获取布局文件
            View v= getLayoutInflater().inflate(R.layout.qr_alert, null);
            
            ImageView i = v.findViewById(R.id.qralertImageView1);
            i.setBackgroundResource(R.drawable.ic_launcher);
            ((TextView)v.findViewById(R.id.qralertTextView1)).setText(url);
            Dialog dialog = new Dialog(this);
            //去掉标题
            dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
            dialog.setContentView(v);
            
            WindowManager.LayoutParams params = dialog.getWindow().getAttributes();
            //获取屏幕60%的宽
            int w= (int)((getWindowManager().getDefaultDisplay().getWidth())*0.6);
            //获取屏幕35%的高
            int h= (int)((getWindowManager().getDefaultDisplay().getHeight())*0.35);
            params.width = w;//设置宽
            params.height = h;//设置高
            dialog.getWindow().setAttributes(params);
            dialog.show();