需求：自定义dialog使其沾满整个屏幕，透明显示（活动弹窗）。

先上代码

布局文件

 <?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:orientation="vertical">

<RelativeLayout
    android:id="@+id/rl_activity"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:visibility="visible">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:orientation="vertical">

        <ImageView
            android:paddingBottom="32dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:src="@drawable/group" />

        <Button
            android:id="@+id/btn_use"
            android:layout_width="match_parent"
            android:layout_height="45dp"
            android:background="@drawable/btn_bg"
            android:text="立即使用"
            android:textColor="@color/white"
            android:textSize="@dimen/dm_18" />

        <ImageView
            android:id="@+id/iv_dismss"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:paddingBottom="35dp"
            android:paddingLeft="50dp"
            android:paddingRight="50dp"
            android:paddingTop="35dp"
            android:src="@drawable/dismiss" />
    </LinearLayout>

</RelativeLayout>

</LinearLayout>

java代码

package com.cfiigroup.zhehui.hepaidai.ui.dialog;

import android.app.Dialog;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.DialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;


public class PromptDialog extends DialogFragment implements View.OnClickListener {

    private Button mBtnUse;
    private ImageView mIvDismss;
    private RelativeLayout mRlActivity;

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setStyle(DialogFragment.STYLE_NORMAL, android.R.style.Theme_Black_NoTitleBar_Fullscreen);
    }

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return super.onCreateDialog(savedInstanceState);

    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE);
        getDialog().setCanceledOnTouchOutside(false);

        setCancelable(true);
        getDialog().getWindow().setBackgroundDrawable(new ColorDrawable(getResources().getColor(R.color.color_dialog_bg)));
        View v = inflater.inflate(R.layout.dialog_customview, null);

        initView(v);
        return v;
    }

    @Override
    public void onStart() {
        super.onStart();
        getDialog().getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
    }

    private void initView(View v) {
        mBtnUse = (Button) v.findViewById(R.id.btn_use);
        mIvDismss = (ImageView) v.findViewById(R.id.iv_dismss);
        mRlActivity = (RelativeLayout) v.findViewById(R.id.rl_activity);
        mBtnUse.setOnClickListener(this);
        mIvDismss.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_use:
                UiManager.callWebActivity(getActivity(), UiManager.webflag_tiyanjin);
                dismiss();
                break;
            case R.id.iv_dismss:
                dismiss();
                break;
        }
    }
    }

分析：定义全屏dailog window去除title 设置主题使其全屏

setStyle(DialogFragment.STYLE_NORMAL, android.R.style.Theme_Black_NoTitleBar_Fullscreen);

getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE);

getDialog().getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);

设置背景透明度

 getDialog().getWindow().setBackgroundDrawable(new ColorDrawable(getResources().getColor(R.color.color_dialog_bg)));