透明对话框式的Activity

项目需求：接受其他app发过来的暗码广播，接收到广播后显示一些信息，由于再Receiver里面不能使用AlertDialog，考虑到使用activity替换，留下笔记以供后续查看

1、增加style

res/values/styles.xml

<style name="dialogstyle" parent="android:style/Theme.Dialog" >
<!--设置dialog的背景-->
<item name="android:windowBackground">@android:color/transparent</item>
<!--设置Dialog的windowFrame框为无-->
<item name="android:windowFrame">@null</item>
<!--设置无标题-->
<item name="android:windowNoTitle">true</item>
<!--是否浮现在activity之上-->
<item name="android:windowIsFloating">true</item>
<!--是否半透明-->
<item name="android:windowIsTranslucent">true</item>
<!--设置窗口内容不覆盖-->
<item name="android:windowContentOverlay">@null</item>
<!--设置动画，在这里使用让它继承系统的Animation.Dialog-->
<item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
<!--背景是否模糊显示-->
<item name="android:backgroundDimEnabled">true</item>
</style>

2、增加layout和activity

layout文件

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright (c) 2014-2015 Qualcomm Technologies, Inc.  All Rights Reserved.
Qualcomm Technologies Proprietary and Confidential.
-->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/transparent"
android:layout_gravity="center" >

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:padding="15dp"
android:background="@android:color/white"
android:orientation="vertical" >

<TextView
android:id="@+id/alert_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginTop="1dp"
android:textColor="@android:color/black"
android:textSize="24sp" />

<TextView
android:id="@+id/alert_info"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginTop="5dp"
android:textColor="@android:color/black"
android:textSize="18sp" />

<TextView
android:id="@+id/alert_ok"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:layout_gravity="end"
android:textColor="@android:color/holo_blue_light"
android:text="@android:string/ok"
android:textSize="18sp"
/>
</LinearLayout>

</RelativeLayout>

activity代码

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.TextView;

/**
* Created by root on 12/24/16.
*/

public class SecretCommonActivity extends Activity {
private TextView mTitletextView;
private TextView mInfoTextView;
private TextView mOKTextView;

private final static String ALERT_TITLE = "alert_title";
private final static String ALERT_INFO = "alert_info";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

/* WindowManager.LayoutParams params = getWindow().getAttributes();
params.flags |= WindowManager.LayoutParams.FLAG_FULLSCREEN;
getWindow().setAttributes(params);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
requestWindowFeature(Window.FEATURE_NO_TITLE);*/

setContentView(R.layout.secret_common);

mTitletextView = (TextView)findViewById(R.id.alert_title);
mInfoTextView = (TextView)findViewById(R.id.alert_info);
mOKTextView = (TextView)findViewById(R.id.alert_ok);

mTitletextView.setText(getIntent().getStringExtra(ALERT_TITLE));
mInfoTextView.setText(getIntent().getStringExtra(ALERT_INFO));

mOKTextView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SecretCommonActivity.this.finish();
}
});
}
}

3、AndroidManifest.xml增加使用style

+        <activity
+            android:name=".SecretCommonActivity"
+            android:label="@string/blank"
+            android:icon="@drawable/alert_info"
+            android:theme="@style/dialogstyle"
+            android:screenOrientation="portrait" >
+        </activity>

4、在Receiver中启动activity

Intent intent = new Intent(context, SecretCommonActivity.class);
intent.putExtra(ALERT_TITLE, "Version Info");
intent.putExtra(ALERT_INFO, versionStr);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
try{
context.startActivity(intent);
} catch (Exception e) {
e.printStackTrace();
}

注：

增加flag ： Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS是为了不在最近列表中显示该activity

附：AlertDialog的使用方法

AlertDialog alert = new AlertDialog.Builder(context)
.setTitle("Version Info")
.setMessage(versionStr)
.setPositiveButton(android.R.string.ok, null)
.setCancelable(false)
.show();