Android杂一

1 Activity转换成View

//activity是当前Activity, XXX是你需要转换成view的Activity

Intent intent = new Intent(activity, XXX.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

Window window = ((ActivityGroup)  activity).getLocalActivityManager().startActivity("XXX",  intent);

//获取到的View

View view =  window.getDecorView();
 

2.ImageView的setBackgroundResource和setImageResource

setBackgroundResource　可以改变图片的大小
而ImageView.setImageResource 无法改变图片的大小.

 

3.AlertDialog设定高宽

 WindowManager.LayoutParams  params = alert.getWindow().getAttributes();
  params.width =300;
  params.height = 100;
  alertDialog.getWindow().setAttributes(params);

4.自动补齐下拉框的下拉列表不显示

  android 的配置文件AndroidManifest.xml中
  android:theme="@style/AppTheme"竟会引起自动补齐下拉框的下拉列表不显示