Android自定义对话框(Dialog)位置,大小

package com.and.mydialog;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MyDialogActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button = (Button) findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {

//                Dialog dialog = new MyDialog(MyDialogActivity.this,
//                        R.style.MyDialog);
//此处直接new一个Dialog对象出来，在实例化的时候传入主题
Dialog dialog = new Dialog(MyDialogActivity.this, R.style.MyDialog);
//设置它的ContentView
dialog.setContentView(R.layout.dialog);

dialog.show();
}
});

}
}