[AppleScript] 小技巧:执行sudo的方法

AppleScript是个强大的好东西,虽然我只是用它来执行一些命令行操作(呃,实际上我还没学怎么进行别的操作),好了废话不多说了,直接进入主题。

在AppleScript中执行终端操作的方法:

    do shell script "SOME COMMANDS"

很简单吧,如果要有管理员权限怎么做,人们自然想到要这样:

    do shell script "sudo SOME COMMANDS"

但是运行一下会出现这个提示:

    AppleScript 错误

    sudo: no tty present and no askpass program specified

解决方法很简单,不要直接把sudo加到里面,而是改成这种形式

    do shell script "SOME COMMANDS" with administrator privileges

这样运行的时候就会弹出那个提示输入管理员密码的那个对话框,sudo的问题就解决了

 

在线编译器推荐–codepad,ideone

以前一直考虑有没有一个在线编译器,今天发现了codepadideone这两个网站

codepad简单介绍:codepad is an online compiler/interpreter, and a simple collaboration tool.

支持C/C++、PHP、Perl、Python、Ruby等语言

选中下面的Run Code即可看到编译/输出结果,总的来讲比较实用。

ideone简单介绍:支持更多的语言,甚至有语法高亮功能,比codepad强大不少,还提供了API,iOS上有个CodeToGo软件使用这个API实现编译功能。

–以上–

iOS 上搭建C/C++开发环境 Beta

11.02.24更新:这有一个别人写的简单版,更方便。

    先说一下效果吧,STL啥的试了几个可用,成功编译了我之前写的一个垃圾程序,过多的测试还没有做,应该能满足基础需求。

    标题之所以加了Beta,是因为笔者也是参考各路教程,东拼西凑才把GCC搭建好的,过程相当混乱,有些步骤也可能有遗漏,因此本文仅供参考,尽量不要完全遵照这个教程。

搭建过程如下:

  1. 当然是越狱,装Cydia,这个不多说了,有锁的注意,小心变砖。
  2. Cydia里安装OpenSSH,APT 0.6 Transitional,Aptitude,wget,unzip,zip
  3. SSH到你的iphone上,这里强烈建议把iphone的root和mobile用户的密码改了,保证机器的安全。
  4. 找一个你喜欢的文件夹:
    wget http://apt.saurik.com/debs/libgcc_4.2-20080410-1-6_iphoneos-arm.deb
    dpkg -i libgcc_4.2-20080410-1-6_iphoneos-arm.deb
    apt-get install iphone-gcc ldid make
    wget下载的那个deb包之后可以删除,随你。另外libgcc那个不用费心去看是否有新版,就用这个就行。
  5. 下载这个附件,把里面的libSystem.dylib放到iphone的 /usr/lib/ 目录下
  6. 这一步仅供测试用,终端上输入:
    echo 'main() { printf("Hello, world!\n"); }' > hello.c
    gcc -o hello hello.c
    ldid -S hello
    ./hello
    ldid是给编译好的程序签名,要不然iphone不会让你运行
  7. 之后就有些混乱了,在Cydia里先后安装了GNU Debugger, C++ Standard Library, iPhone 2.0 Toolchain, 这里面也许有不需要的,但是不想再刷机测试一下。
  8. 现在如果我没有遗漏什么步骤的话,测试stdio.h等c的头文件应该是OK的,C++的iostream等好像还不行,编译时提示应该是找不到usr/include/c++/4.0.0/bits/c++config.h这个文件。此时把第5步中下载的那个附件中的include.tar.gz中的usr/include/c++/4.0.0/ 中的arm-apple-darwin8,拷贝到iphone /usr/include/c++/4.0.0/ 下,然后在bits/ 中建立arm-apple-darwin8/ 中所有文件的链接,因为这里有我们需要的c++config.h,直接拷贝这些文件到bits下也应该可以。
  9. 之后用g++编译一个测试文件出现的错误提示应该是找不到 -lstdc++,原因其实是缺少libstdc++.dylib这个文件,这个文件我是在XCode里面找的,尝试了几个找到了个好用的,但是不知道具体是哪一个了,第5步那个附件里也提供了,是从iphone中拷出来的,应该好用。

到此就应该能实现预期的目标了,我能回忆起的过程也就是这些了,大家有问题留言吧。

附参考文献:

  1. 【ipod4g出品】用 iPhone gcc 编译 iPhone SDK 游戏(真机开发、运行及调试) 
  2. iphone-gcc

Android Dev:VideoView源代码浅析及拓展应用

做Android开发不免要涉及到编写媒体播放器,对于初学者来说用MediaPlayer实现一个具有基本功能的播放器(有进度条,可以通过进度条上的按钮进行控制)还是有一定难度的,幸好Android还提供了一个VideoView类,借用该类可以快速实现简单的媒体播放功能,其源代码如下(单击右边那个箭头展开):

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.widget;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.res.Resources;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.Metadata;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.net.Uri;
import android.os.PowerManager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.MediaController.*;

import java.io.IOException;
import java.util.Map;

/**
 * Displays a video file.  The VideoView class
 * can load images from various sources (such as resources or content
 * providers), takes care of computing its measurement from the video so that
 * it can be used in any layout manager, and provides various display options
 * such as scaling and tinting.
 */
public class VideoView extends SurfaceView implements MediaPlayerControl {
    private String TAG = "VideoView";
    // settable by the client
    private Uri         mUri;
    private Map mHeaders;
    private int         mDuration;

    // all possible internal states
    private static final int STATE_ERROR              = -1;
    private static final int STATE_IDLE               = 0;
    private static final int STATE_PREPARING          = 1;
    private static final int STATE_PREPARED           = 2;
    private static final int STATE_PLAYING            = 3;
    private static final int STATE_PAUSED             = 4;
    private static final int STATE_PLAYBACK_COMPLETED = 5;
    private static final int STATE_SUSPEND            = 6;
    private static final int STATE_RESUME             = 7;
    private static final int STATE_SUSPEND_UNSUPPORTED = 8;

    // mCurrentState is a VideoView object's current state.
    // mTargetState is the state that a method caller intends to reach.
    // For instance, regardless the VideoView object's current state,
    // calling pause() intends to bring the object to a target state
    // of STATE_PAUSED.
    private int mCurrentState = STATE_IDLE;
    private int mTargetState  = STATE_IDLE;

    // All the stuff we need for playing and showing a video
    private SurfaceHolder mSurfaceHolder = null;
    private MediaPlayer mMediaPlayer = null;
    private int         mVideoWidth;
    private int         mVideoHeight;
    private int         mSurfaceWidth;
    private int         mSurfaceHeight;
    private MediaController mMediaController;
    private OnCompletionListener mOnCompletionListener;
    private MediaPlayer.OnPreparedListener mOnPreparedListener;
    private int         mCurrentBufferPercentage;
    private OnErrorListener mOnErrorListener;
    private int         mSeekWhenPrepared;  // recording the seek position while preparing
    private boolean     mCanPause;
    private boolean     mCanSeekBack;
    private boolean     mCanSeekForward;
    private int         mStateWhenSuspended;  //state before calling suspend()

    public VideoView(Context context) {
        super(context);
        initVideoView();
    }

    public VideoView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        initVideoView();
    }

    public VideoView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initVideoView();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        //Log.i("@@@@", "onMeasure");
        int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
        int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
        if (mVideoWidth > 0 && mVideoHeight > 0) {
            if ( mVideoWidth * height  > width * mVideoHeight ) {
                //Log.i("@@@", "image too tall, correcting");
                height = width * mVideoHeight / mVideoWidth;
            } else if ( mVideoWidth * height  < width * mVideoHeight ) {
                //Log.i("@@@", "image too wide, correcting");
                width = height * mVideoWidth / mVideoHeight;
            } else {
                //Log.i("@@@", "aspect ratio is correct: " +
                        //width+"/"+height+"="+
                        //mVideoWidth+"/"+mVideoHeight);
            }
        }
        //Log.i("@@@@@@@@@@", "setting size: " + width + 'x' + height);
        setMeasuredDimension(width, height);
    }

    public int resolveAdjustedSize(int desiredSize, int measureSpec) {
        int result = desiredSize;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize =  MeasureSpec.getSize(measureSpec);

        switch (specMode) {
            case MeasureSpec.UNSPECIFIED:
                /* Parent says we can be as big as we want. Just don't be larger
                 * than max size imposed on ourselves.
                 */
                result = desiredSize;
                break;

            case MeasureSpec.AT_MOST:
                /* Parent says we can be as big as we want, up to specSize.
                 * Don't be larger than specSize, and don't be larger than
                 * the max size imposed on ourselves.
                 */
                result = Math.min(desiredSize, specSize);
                break;

            case MeasureSpec.EXACTLY:
                // No choice. Do what we are told.
                result = specSize;
                break;
        }
        return result;
}

    private void initVideoView() {
        mVideoWidth = 0;
        mVideoHeight = 0;
        getHolder().addCallback(mSHCallback);
        getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        setFocusable(true);
        setFocusableInTouchMode(true);
        requestFocus();
        mCurrentState = STATE_IDLE;
        mTargetState  = STATE_IDLE;
    }

    public void setVideoPath(String path) {
        setVideoURI(Uri.parse(path));
    }

    public void setVideoURI(Uri uri) {
        setVideoURI(uri, null);
    }

    /**
     * @hide
     */
    public void setVideoURI(Uri uri, Map headers) {
        mUri = uri;
        mHeaders = headers;
        mSeekWhenPrepared = 0;
        openVideo();
        requestLayout();
        invalidate();
    }

    public void stopPlayback() {
        if (mMediaPlayer != null) {
            mMediaPlayer.stop();
            mMediaPlayer.release();
            mMediaPlayer = null;
            mCurrentState = STATE_IDLE;
            mTargetState  = STATE_IDLE;
        }
    }

    private void openVideo() {
        if (mUri == null || mSurfaceHolder == null) {
            // not ready for playback just yet, will try again later
            return;
        }
        // Tell the music playback service to pause
        // TODO: these constants need to be published somewhere in the framework.
        Intent i = new Intent("com.android.music.musicservicecommand");
        i.putExtra("command", "pause");
        mContext.sendBroadcast(i);

        // we shouldn't clear the target state, because somebody might have
        // called start() previously
        release(false);
        try {
            mMediaPlayer = new MediaPlayer();
            mMediaPlayer.setOnPreparedListener(mPreparedListener);
            mMediaPlayer.setOnVideoSizeChangedListener(mSizeChangedListener);
            mDuration = -1;
            mMediaPlayer.setOnCompletionListener(mCompletionListener);
            mMediaPlayer.setOnErrorListener(mErrorListener);
            mMediaPlayer.setOnBufferingUpdateListener(mBufferingUpdateListener);
            mCurrentBufferPercentage = 0;
            mMediaPlayer.setDataSource(mContext, mUri, mHeaders);
            mMediaPlayer.setDisplay(mSurfaceHolder);
            mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
            mMediaPlayer.setScreenOnWhilePlaying(true);
            mMediaPlayer.prepareAsync();
            // we don't set the target state here either, but preserve the
            // target state that was there before.
            mCurrentState = STATE_PREPARING;
            attachMediaController();
        } catch (IOException ex) {
            Log.w(TAG, "Unable to open content: " + mUri, ex);
            mCurrentState = STATE_ERROR;
            mTargetState = STATE_ERROR;
            mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);
            return;
        } catch (IllegalArgumentException ex) {
            Log.w(TAG, "Unable to open content: " + mUri, ex);
            mCurrentState = STATE_ERROR;
            mTargetState = STATE_ERROR;
            mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);
            return;
        }
    }

    public void setMediaController(MediaController controller) {
        if (mMediaController != null) {
            mMediaController.hide();
        }
        mMediaController = controller;
        attachMediaController();
    }

    private void attachMediaController() {
        if (mMediaPlayer != null && mMediaController != null) {
            mMediaController.setMediaPlayer(this);
            View anchorView = this.getParent() instanceof View ?
                    (View)this.getParent() : this;
            mMediaController.setAnchorView(anchorView);
            mMediaController.setEnabled(isInPlaybackState());
        }
    }

    MediaPlayer.OnVideoSizeChangedListener mSizeChangedListener =
        new MediaPlayer.OnVideoSizeChangedListener() {
            public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
                mVideoWidth = mp.getVideoWidth();
                mVideoHeight = mp.getVideoHeight();
                if (mVideoWidth != 0 && mVideoHeight != 0) {
                    getHolder().setFixedSize(mVideoWidth, mVideoHeight);
                }
            }
    };

    MediaPlayer.OnPreparedListener mPreparedListener = new MediaPlayer.OnPreparedListener() {
        public void onPrepared(MediaPlayer mp) {
            mCurrentState = STATE_PREPARED;

            // Get the capabilities of the player for this stream
            Metadata data = mp.getMetadata(MediaPlayer.METADATA_ALL,
                                      MediaPlayer.BYPASS_METADATA_FILTER);

            if (data != null) {
                mCanPause = !data.has(Metadata.PAUSE_AVAILABLE)
                        || data.getBoolean(Metadata.PAUSE_AVAILABLE);
                mCanSeekBack = !data.has(Metadata.SEEK_BACKWARD_AVAILABLE)
                        || data.getBoolean(Metadata.SEEK_BACKWARD_AVAILABLE);
                mCanSeekForward = !data.has(Metadata.SEEK_FORWARD_AVAILABLE)
                        || data.getBoolean(Metadata.SEEK_FORWARD_AVAILABLE);
            } else {
                mCanPause = mCanSeekBack = mCanSeekForward = true;
            }

            if (mOnPreparedListener != null) {
                mOnPreparedListener.onPrepared(mMediaPlayer);
            }
            if (mMediaController != null) {
                mMediaController.setEnabled(true);
            }
            mVideoWidth = mp.getVideoWidth();
            mVideoHeight = mp.getVideoHeight();

            int seekToPosition = mSeekWhenPrepared;  // mSeekWhenPrepared may be changed after seekTo() call
            if (seekToPosition != 0) {
                seekTo(seekToPosition);
            }
            if (mVideoWidth != 0 && mVideoHeight != 0) {
                //Log.i("@@@@", "video size: " + mVideoWidth +"/"+ mVideoHeight);
                getHolder().setFixedSize(mVideoWidth, mVideoHeight);
                if (mSurfaceWidth == mVideoWidth && mSurfaceHeight == mVideoHeight) {
                    // We didn't actually change the size (it was already at the size
                    // we need), so we won't get a "surface changed" callback, so
                    // start the video here instead of in the callback.
                    if (mTargetState == STATE_PLAYING) {
                        start();
                        if (mMediaController != null) {
                            mMediaController.show();
                        }
                    } else if (!isPlaying() &&
                               (seekToPosition != 0 || getCurrentPosition() > 0)) {
                       if (mMediaController != null) {
                           // Show the media controls when we're paused into a video and make 'em stick.
                           mMediaController.show(0);
                       }
                   }
                }
            } else {
                // We don't know the video size yet, but should start anyway.
                // The video size might be reported to us later.
                if (mTargetState == STATE_PLAYING) {
                    start();
                }
            }
        }
    };

    private MediaPlayer.OnCompletionListener mCompletionListener =
        new MediaPlayer.OnCompletionListener() {
        public void onCompletion(MediaPlayer mp) {
            mCurrentState = STATE_PLAYBACK_COMPLETED;
            mTargetState = STATE_PLAYBACK_COMPLETED;
            if (mMediaController != null) {
                mMediaController.hide();
            }
            if (mOnCompletionListener != null) {
                mOnCompletionListener.onCompletion(mMediaPlayer);
            }
        }
    };

    private MediaPlayer.OnErrorListener mErrorListener =
        new MediaPlayer.OnErrorListener() {
        public boolean onError(MediaPlayer mp, int framework_err, int impl_err) {
            Log.d(TAG, "Error: " + framework_err + "," + impl_err);
            mCurrentState = STATE_ERROR;
            mTargetState = STATE_ERROR;
            if (mMediaController != null) {
                mMediaController.hide();
            }

            /* If an error handler has been supplied, use it and finish. */
            if (mOnErrorListener != null) {
                if (mOnErrorListener.onError(mMediaPlayer, framework_err, impl_err)) {
                    return true;
                }
            }

            /* Otherwise, pop up an error dialog so the user knows that
             * something bad has happened. Only try and pop up the dialog
             * if we're attached to a window. When we're going away and no
             * longer have a window, don't bother showing the user an error.
             */
            if (getWindowToken() != null) {
                Resources r = mContext.getResources();
                int messageId;

                if (framework_err == MediaPlayer.MEDIA_ERROR_NOT_VALID_FOR_PROGRESSIVE_PLAYBACK) {
                    messageId = com.android.internal.R.string.VideoView_error_text_invalid_progressive_playback;
                } else {
                    messageId = com.android.internal.R.string.VideoView_error_text_unknown;
                }

                new AlertDialog.Builder(mContext)
                        .setTitle(com.android.internal.R.string.VideoView_error_title)
                        .setMessage(messageId)
                        .setPositiveButton(com.android.internal.R.string.VideoView_error_button,
                                new DialogInterface.OnClickListener() {
                                    public void onClick(DialogInterface dialog, int whichButton) {
                                        /* If we get here, there is no onError listener, so
                                         * at least inform them that the video is over.
                                         */
                                        if (mOnCompletionListener != null) {
                                            mOnCompletionListener.onCompletion(mMediaPlayer);
                                        }
                                    }
                                })
                        .setCancelable(false)
                        .show();
            }
            return true;
        }
    };

    private MediaPlayer.OnBufferingUpdateListener mBufferingUpdateListener =
        new MediaPlayer.OnBufferingUpdateListener() {
        public void onBufferingUpdate(MediaPlayer mp, int percent) {
            mCurrentBufferPercentage = percent;
        }
    };

    /**
     * Register a callback to be invoked when the media file
     * is loaded and ready to go.
     *
     * @param l The callback that will be run
     */
    public void setOnPreparedListener(MediaPlayer.OnPreparedListener l)
    {
        mOnPreparedListener = l;
    }

    /**
     * Register a callback to be invoked when the end of a media file
     * has been reached during playback.
     *
     * @param l The callback that will be run
     */
    public void setOnCompletionListener(OnCompletionListener l)
    {
        mOnCompletionListener = l;
    }

    /**
     * Register a callback to be invoked when an error occurs
     * during playback or setup.  If no listener is specified,
     * or if the listener returned false, VideoView will inform
     * the user of any errors.
     *
     * @param l The callback that will be run
     */
    public void setOnErrorListener(OnErrorListener l)
    {
        mOnErrorListener = l;
    }

    SurfaceHolder.Callback mSHCallback = new SurfaceHolder.Callback()
    {
        public void surfaceChanged(SurfaceHolder holder, int format,
                                    int w, int h)
        {
            mSurfaceWidth = w;
            mSurfaceHeight = h;
            boolean isValidState =  (mTargetState == STATE_PLAYING);
            boolean hasValidSize = (mVideoWidth == w && mVideoHeight == h);
            if (mMediaPlayer != null && isValidState && hasValidSize) {
                if (mSeekWhenPrepared != 0) {
                    seekTo(mSeekWhenPrepared);
                }
                start();
                if (mMediaController != null) {
                    mMediaController.show();
                }
            }
        }

        public void surfaceCreated(SurfaceHolder holder)
        {
            mSurfaceHolder = holder;
            //resume() was called before surfaceCreated()
            if (mMediaPlayer != null && mCurrentState == STATE_SUSPEND
                   && mTargetState == STATE_RESUME) {
                mMediaPlayer.setDisplay(mSurfaceHolder);
                resume();
            } else {
                openVideo();
            }
        }

        public void surfaceDestroyed(SurfaceHolder holder)
        {
            // after we return from this we can't use the surface any more
            mSurfaceHolder = null;
            if (mMediaController != null) mMediaController.hide();
            if (mCurrentState != STATE_SUSPEND) {
                release(true);
            }
        }
    };

    /*
     * release the media player in any state
     */
    private void release(boolean cleartargetstate) {
        if (mMediaPlayer != null) {
            mMediaPlayer.reset();
            mMediaPlayer.release();
            mMediaPlayer = null;
            mCurrentState = STATE_IDLE;
            if (cleartargetstate) {
                mTargetState  = STATE_IDLE;
            }
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (isInPlaybackState() && mMediaController != null) {
            toggleMediaControlsVisiblity();
        }
        return false;
    }

    @Override
    public boolean onTrackballEvent(MotionEvent ev) {
        if (isInPlaybackState() && mMediaController != null) {
            toggleMediaControlsVisiblity();
        }
        return false;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        boolean isKeyCodeSupported = keyCode != KeyEvent.KEYCODE_BACK &&
                                     keyCode != KeyEvent.KEYCODE_VOLUME_UP &&
                                     keyCode != KeyEvent.KEYCODE_VOLUME_DOWN &&
                                     keyCode != KeyEvent.KEYCODE_MENU &&
                                     keyCode != KeyEvent.KEYCODE_CALL &&
                                     keyCode != KeyEvent.KEYCODE_ENDCALL;
        if (isInPlaybackState() && isKeyCodeSupported && mMediaController != null) {
            if (keyCode == KeyEvent.KEYCODE_HEADSETHOOK ||
                    keyCode == KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE) {
                if (mMediaPlayer.isPlaying()) {
                    pause();
                    mMediaController.show();
                } else {
                    start();
                    mMediaController.hide();
                }
                return true;
            } else if (keyCode == KeyEvent.KEYCODE_MEDIA_STOP
                    && mMediaPlayer.isPlaying()) {
                pause();
                mMediaController.show();
            } else {
                toggleMediaControlsVisiblity();
            }
        }

        return super.onKeyDown(keyCode, event);
    }

    private void toggleMediaControlsVisiblity() {
        if (mMediaController.isShowing()) {
            mMediaController.hide();
        } else {
            mMediaController.show();
        }
    }

    public void start() {
        if (isInPlaybackState()) {
            mMediaPlayer.start();
            mCurrentState = STATE_PLAYING;
        }
        mTargetState = STATE_PLAYING;
    }

    public void pause() {
        if (isInPlaybackState()) {
            if (mMediaPlayer.isPlaying()) {
                mMediaPlayer.pause();
                mCurrentState = STATE_PAUSED;
            }
        }
        mTargetState = STATE_PAUSED;
    }

    public void suspend() {
        if (isInPlaybackState()) {
            if (mMediaPlayer.suspend()) {
                mStateWhenSuspended = mCurrentState;
                mCurrentState = STATE_SUSPEND;
                mTargetState = STATE_SUSPEND;
            } else {
                release(false);
                mCurrentState = STATE_SUSPEND_UNSUPPORTED;
                Log.w(TAG, "Unable to suspend video. Release MediaPlayer.");
            }
        }
    }

    public void resume() {
        if (mSurfaceHolder == null && mCurrentState == STATE_SUSPEND){
            mTargetState = STATE_RESUME;
            return;
        }
        if (mMediaPlayer != null && mCurrentState == STATE_SUSPEND) {
            if (mMediaPlayer.resume()) {
                mCurrentState = mStateWhenSuspended;
                mTargetState = mStateWhenSuspended;
            } else {
                Log.w(TAG, "Unable to resume video");
            }
            return;
        }
        if (mCurrentState == STATE_SUSPEND_UNSUPPORTED) {
            openVideo();
        }
    }

   // cache duration as mDuration for faster access
    public int getDuration() {
        if (isInPlaybackState()) {
            if (mDuration > 0) {
                return mDuration;
            }
            mDuration = mMediaPlayer.getDuration();
            return mDuration;
        }
        mDuration = -1;
        return mDuration;
    }

    public int getCurrentPosition() {
        if (isInPlaybackState()) {
            return mMediaPlayer.getCurrentPosition();
        }
        return 0;
    }

    public void seekTo(int msec) {
        if (isInPlaybackState()) {
            mMediaPlayer.seekTo(msec);
            mSeekWhenPrepared = 0;
        } else {
            mSeekWhenPrepared = msec;
        }
    }

    public boolean isPlaying() {
        return isInPlaybackState() && mMediaPlayer.isPlaying();
    }

    public int getBufferPercentage() {
        if (mMediaPlayer != null) {
            return mCurrentBufferPercentage;
        }
        return 0;
    }

    private boolean isInPlaybackState() {
        return (mMediaPlayer != null &&
                mCurrentState != STATE_ERROR &&
                mCurrentState != STATE_IDLE &&
                mCurrentState != STATE_PREPARING);
    }

    public boolean canPause() {
        return mCanPause;
    }

    public boolean canSeekBackward() {
        return mCanSeekBack;
    }

    public boolean canSeekForward() {
        return mCanSeekForward;
    }
}

继续阅读Android Dev:VideoView源代码浅析及拓展应用

Mac OS 下命令行编辑plist的方法

    一般我们编辑plist文件都是直接打开,用PlistEditor什么的进行可视化编辑,但是如果想用脚本编辑plist文件就要用到命令行了,其实这是一个很简单的命令:defaults

    defaults 命令的帮助如下

'defaults' [-currentHost | -host ] followed by one of the following:

  read                                 shows all defaults
  read                         shows defaults for given domain
  read                    shows defaults for given domain, key

  read-type               shows the type for the given domain, key

  write            writes domain (overwrites existing)
  write            writes key for domain

  rename 
   renames old_key to new_key

  delete                       deletes domain
  delete                  deletes key in domain

  domains                              lists all domains
  find                           lists all entries containing word
  help                                 print this help

 is (  | -app  | -globalDomain )
         or a path to a file omitting the '.plist' extension

 is one of:
  
  -string 
  -data 
  -int[eger] 
  -float  
  -bool[ean] (true | false | yes | no)
  -date 
  -array   ...
  -array-add   ...
  -dict     ...
  -dict-add  

 

    光看这些就大概知道怎么弄了吧,下面是几个例子:

defaults read com.xxx.xxx // 输出文件中所有信息
defaults write com.xxx.xxx   // 改变某个key的value,如果没有该key则添�

 

    注意:在 "com.xxx.xxx" 之后没有 ".plist",开始我犯了这个错误,弄半天不知道为何plist文件中的值没有改变。

   (END)