19_B门长时曝光APP

浏览数：32 / 时间：2015年06月11日

知识很基础……

前几天买了个单反，特别想拍B门长时间曝光的效果。后来想想不如自己写个APP，实现屏幕背景的随机颜色以及全屏显示文字。

先上图：

这两张图片的左侧都很亮，这是因为APP里面忘记把"状态栏"隐藏了。两张照片的快门都是30s，APP的基本功能就是设定好文字，点击屏幕就会显示一个字；再点击屏幕编程黑色；再次点击屏幕出现下一个字。我在屏幕全黑的时候移动手机，到合适位置点击屏幕，显示出下一个字。同时屏幕还能够按照设定的时间间隔，显示出随机的颜色。为了使显示的颜色更鲜艳，在RGB颜色合成的时候，RGB的随机值都是从80~255。

同时文字在显示的时候，角度从45°到135°随机出现，这要在拍照时手机正常摆放，也不至于太过呆板。

下面是APP截图：

运行时的截图：

程序代码如下：

package com.example.raw;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends Activity {

    public int redColor = 0;
    public int blueColor = 0;
    public int greenColor = 0;

    public int tvRedColor = 0;
    public int tvBlueColor = 0;
    public int tvGreenColor = 0;

    public int tvRotation = 0;
    public int clickTimes = 0;
    public int i = 0;

    public char[] text = null;

    public boolean enableView = false;

    private LinearLayout ll;
    private TimerTask task;
    private Button btnTimeInterval, btnSetText;
    private TextView etTimeInterval, editSetText, tvFullScreen, tvScreenLight;
    private SeekBar seekBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        seekBar = (SeekBar) findViewById(R.id.seekBar);
        seekBar.setMax(100);

        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {

            public void onStopTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            public void onStartTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            public void onProgressChanged(SeekBar seekBar, int progress,
                    boolean fromUser) {
                WindowManager.LayoutParams lp = getWindow().getAttributes();
                lp.screenBrightness = (float) (progress / 100.0);
                getWindow().setAttributes(lp);
            }
        });

        ll = (LinearLayout) findViewById(R.id.root);
        ll.setBackgroundColor(0XFFFFFFFF);

        btnTimeInterval = (Button) findViewById(R.id.btnTimeInterval);
        btnSetText = (Button) findViewById(R.id.btnSetText);

        etTimeInterval = (TextView) findViewById(R.id.etTimeInterval);
        editSetText = (TextView) findViewById(R.id.editSetText);
        tvFullScreen = (TextView) findViewById(R.id.tvFullScreen);
        tvScreenLight = (TextView) findViewById(R.id.tvScreenLight);

        final Handler handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                switch (msg.what) {
                case 1:
                    redColor = (int) (80 + Math.random() * 175);
                    blueColor = (int) (80 + Math.random() * 175);
                    greenColor = (int) (80 + Math.random() * 175);
                    ll.setBackgroundColor(0xff000000 + redColor * 255 * 255
                            + blueColor * 255 + greenColor);
                    break;
                default:
                    break;
                }
                super.handleMessage(msg);
            }
        };

        btnTimeInterval.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {

                try {
                    if (etTimeInterval.getText() != null) {
                        setAllUiVisibilityGone();
                        tvFullScreen.setVisibility(8);
                        Timer timer = new Timer(true);
                        timer.schedule(task, 1000, Integer
                                .parseInt(etTimeInterval.getText().toString()));
                    }

                } catch (Exception e) {

                }

            }
        });

        btnSetText.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {

                try {
                    if (editSetText.getText() != null) {
                        setAllUiVisibilityGone();
                        text = editSetText.getText().toString().toCharArray();
                        tvFullScreen.setBackgroundColor(0xff000000);
                        ll.setBackgroundColor(0xff000000);
                        enableView = true;
                    }

                } catch (Exception e) {
                    // TODO: handle exception
                }
            }
        });

        ll.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                if (enableView == true) {
                    clickTimes++;
                    if (clickTimes % 2 == 1) {
                        tvFullScreen.setBackgroundColor(0xff000000);
                        ll.setBackgroundColor(0xff000000);

                        tvRotation = (int) (45 + Math.random() * 90);
                        tvFullScreen.setRotation(tvRotation);

                        tvRedColor = (int) (100 + Math.random() * 155);
                        tvBlueColor = (int) (100 + Math.random() * 155);
                        tvGreenColor = (int) (100 + Math.random() * 155);
                        tvFullScreen.setTextColor(0xff000000 + tvRedColor * 255
                                * 255 + tvBlueColor * 255 + tvGreenColor);

                        if (i < text.length) {
                            tvFullScreen.setText(text, i++, 1);
                        } else {
                            tvFullScreen.setTextColor(0xff000000);
                        }

                    } else {
                        tvFullScreen.setBackgroundColor(0xff000000);
                        tvFullScreen.setTextColor(0xff000000);
                        ll.setBackgroundColor(0xff000000);
                    }
                }
            }
        });

        task = new TimerTask() {

            @Override
            public void run() {
                Message message = new Message();
                message.what = 1;
                handler.sendMessage(message);
            }
        };

    }

    public void setAllUiVisibilityGone() {
        btnTimeInterval.setVisibility(8);
        etTimeInterval.setVisibility(8);
        btnSetText.setVisibility(8);
        editSetText.setVisibility(8);
        seekBar.setVisibility(8);
        tvScreenLight.setVisibility(8);
    }
}

MainActivity

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/root"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffffffff"
    android:orientation="vertical"
    tools:context="com.example.raw.MainActivity" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <EditText
            android:id="@+id/etTimeInterval"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:ems="10"
            android:hint="输入时间间隔"
            android:inputType="numberDecimal" >

            <requestFocus />
        </EditText>

        <Button
            android:id="@+id/btnTimeInterval"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="3"
            android:text="设定间隔" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <EditText
            android:id="@+id/editSetText"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:ems="10"
            android:hint="输入文字" />

        <Button
            android:id="@+id/btnSetText"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="3"
            android:text="设定文字" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <SeekBar
            android:id="@+id/seekBar"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2" />

        <TextView
            android:id="@+id/tvScreenLight"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="屏幕亮度" 
            android:layout_weight="3"
            android:gravity="center"
            android:textSize="20sp"/>
    </LinearLayout>

    <TextView
        android:id="@+id/tvFullScreen"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:text=""
        android:textSize="280sp" />

</LinearLayout>