【Android】Activity遮罩效果的实现

Activity文件

package com.app.test02;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.TextView;


public class ShadeActivity extends Activity {
	// 设置是否展开
	private boolean isFolded = true;
	// 设置控件
	private FrameLayout layout = null;
	private Button unfoldButton = null;
	private TextView textView = null;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.activity_shade);

		initView();
	}

	@Override
	protected void onResume() {
		// TODO Auto-generated method stu
		super.onResume();
		isFolded = true;
	}

	// 初始化
	private void initView() {
		layout = (FrameLayout) findViewById(R.id.layout);
		unfoldButton = (Button) findViewById(R.id.unfoldButton);
		unfoldButton.setOnClickListener(new UnfoldClickListener());
	}

	// 按钮监听，展开一个透明的显示文本的遮挡层
	private class UnfoldClickListener implements OnClickListener {
		public void onClick(View v) {
			if (isFolded) {
				textView = new TextView(ShadeActivity.this);
				textView.setTextColor(Color.BLUE);
				textView.setTextSize(20);
				textView.setText("滚滚长江东逝水，浪花淘尽英雄。
" + "是非成败转头空，
"
						+ "青山依旧在，几度夕阳红。
" + "白发渔樵江渚上，惯看秋月春风。 
"
						+ "一壶浊酒喜相逢，
" + "古今多少事，都付笑谈中。");
				textView.setGravity(Gravity.CENTER);
				textView.setLayoutParams(new ViewGroup.LayoutParams(
						ViewGroup.LayoutParams.FILL_PARENT,
						ViewGroup.LayoutParams.FILL_PARENT));
				textView.setBackgroundColor(Color.parseColor("#86222222"));

				unfoldButton.setText("取消遮罩");

				isFolded = false;

				layout.addView(textView);
			} else {
				unfoldButton.setText("显示遮罩");
				isFolded = true;
				layout.removeView(textView);
			}
		}
	}
}

XML布局文件

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/layout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" 
    android:background="#fff">

    <Gallery
        android:id="@+id/showGallery"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:spacing="0dip" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="#86222222"
        android:orientation="horizontal" >

        <TextView
            android:id="@+id/titleTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="遮罩效果"
            android:textColor="#ff0000" />

        <Button
            android:id="@+id/unfoldButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:text="显示遮罩" />
    </RelativeLayout>

</FrameLayout>

效果图