dialog的应用

public static Dialog creatRequestDialog(final Context context, String tip) {

        final Dialog dialog = new Dialog(context, R.style.dialog);

        // dialog.setCancelable(false);
        // dialog.setCanceledOnTouchOutside(false);

        dialog.setContentView(R.layout.dialog_layout);
        Window window = dialog.getWindow();
        WindowManager.LayoutParams lp = window.getAttributes();
        int width = Utils.getScreenWidth(context);
        lp.width = (int) (0.5 * width);

        TextView titleTxtv = (TextView) dialog.findViewById(R.id.tvLoad);
        titleTxtv.setText(tip);

        return dialog;
       }

<style name="dialog" parent="@android:style/Theme.Dialog">
        <item name="android:windowIsFloating">true</item>
        <!-- 设置未浮动窗口 -->
        <item name="android:windowFrame">@null</item>
        <!-- 设置无边框 -->
        <item name="android:windowNoTitle">true</item>
        <!-- 设置无标题 -->
        <item name="android:windowBackground">@color/sc_transparent_background</item>
        <!-- 设置完全透明 -->
        <item name="android:backgroundDimEnabled">true</item>
        <!-- 设置屏幕变暗 -->
    </style>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/loading_bg"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    android:paddingBottom="15dp"
    android:paddingLeft="20dp"
    android:paddingRight="20dp"
    android:paddingTop="15dp" >

    <ProgressBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:indeterminateDrawable="@drawable/frame_loading" />

    <TextView
        android:id="@+id/tvLoad"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="5dp"
        android:textColor="#ffffffff"
        android:textSize="17.0sp" />

</LinearLayout>

public void showRequestDialog(String msg) {
        if (mDialog != null) {
            mDialog.dismiss();
            mDialog = null;
        }
        mDialog = DialogFactory.creatRequestDialog(this, msg);
        // mDialog.setCancelable(false);
        mDialog.setCanceledOnTouchOutside(false);//防止4.0系统点击dialog之外时出现崩溃问题
         mDialog.show();
    }
    //关闭Dialog
public void closeRequestDialog() {
      if (mDialog != null) {
            mDialog.dismiss();
            mDialog = null;
       }

    }
    //回退
    @Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
    }