AlertDialog.Builder(this,R.style.dialogNoBg).create(); 

 <!--dialog去陰影-->
 <style name="dialogNoBg">
 <item name="android:background">#00000000</item>
 <item name="android:windowBackground">@android:color/transparent</item>
 <item name="android:windowNoTitle">true</item>
 <item name="android:windowIsFloating">true</item>
 </style>

private AlertDialog dialog;

 private void showdialogCashOut() {
 dialog = new AlertDialog.Builder(this,R.style.dialogNoBg).create();
 View view = View.inflate(this, R.layout.cash_see_out_dialog, null);
 dialog.getWindow().setContentView(view);
 TextView tv_money = (TextView) dialog.findViewById(R.id.tv_money);
 tv_money.setText(Html.fromHtml("<font color='#FF2850'>注意：</font>"+getResources().getString(R.string.cash_out_dialog)));
 TextView cancle_ye = (TextView) view.findViewById(R.id.dialog_cancel);
 cancle_ye.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {
  dialog.dismiss();
  }
 });
 TextView yes_ye = (TextView) view.findViewById(R.id.dialog_yes);
 yes_ye.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {
  dialog.dismiss();
  }
 });

 }