如何给Android中的按钮添加图片功能

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:gravity="center"

    android:background="@drawable/app_icon"

    android:orientation="vertical">

      android:id="@+id/startOrder_btn"

      android:layout_width="fill_parent"

      android:layout_height="fill_parent"

      android:background="@drawable/apply"

      android:textSize="25sp">

      android:id="@+id/managerOrder_btn"

      android:layout_width="fill_parent"

      android:layout_height="fill_parent"

      android:background="@drawable/apply"

      android:textSize="25sp">

LayoutInflater inflater = LayoutInflater.from(mMainActivity);

  View layout=inflater.inflate(R.layout.my_login,null);

  ContextThemeWrapper contextThemeWrapper =newContextThemeWrapper(MainActivity.this,2131099656);

  AlertDialog.Builder builder =newAlertDialog.Builder(contextThemeWrapper);

  builder.setView(layout);

  builder.setCancelable(false);

  builder.create().show();

  Button startOrder_btn=(Button) layout.findViewById(R.id.startOrder_btn);

  Button managerOrder_btn=(Button) layout.findViewById(R.id.managerOrder_btn);

  startOrder_btn.setOnClickListener(newOnClickListener(){

  publicvoidonClick(View v) {

  //加上你要实现的代码

  YSDKApi.login(ePlatform.QQ);

  }

  });

  managerOrder_btn.setOnClickListener(newOnClickListener(){

  publicvoidonClick(View v) {//加上你要实现的代码

  YSDKApi.login(ePlatform.WX);

  }

  });