android实用代码积累

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一，.自定义标题栏

1.Oncreate中实现关键性代码

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);//必须在setcontentview方法之前调用
        setContentView(R.layout.supervise);
       getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.titlebar);//设置自定义标题
       back=(ImageButton)findViewById(R.id.imageButton1);
       title=(TextView)findViewById(R.id.textView1);
       title.setText(R.string.Supervise);
       back.setOnClickListener(this);

}

2.titleBar布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:gravity="center_vertical"

        >

3.实用style定义标题栏风格，宽度，背景等

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style parent="android:Theme" name="titleStyle">
        <item name="android:windowTitleSize">40dp</item>
    </style>

</resources>

二。获取APK未安装包的ICON及Label、

1.获取ICON

public static Drawable getApkIcon(Context context,File file) {
    String apkPath=file.getAbsolutePath();
         PackageManager pm = context.getPackageManager();

         PackageInfo info = pm.getPackageArchiveInfo(apkPath, 0);
         if (info != null) {
             ApplicationInfo appInfo = info.applicationInfo;
             appInfo.publicSourceDir=apkPath;
             try {

                 return zoomDrawable(appInfo.loadIcon(pm), 48, 48);
             } catch (OutOfMemoryError e) {
                 Log.e("ApkIconLoader", e.toString());
             }
         }
         return null;
     }

2 public static String getApkLabel(Context context, File file) {
   String apkPath=file.getAbsolutePath();
         PackageManager pm = context.getPackageManager();
         PackageInfo info = pm.getPackageArchiveInfo(apkPath, 0);
         if (info != null) {
             ApplicationInfo appInfo = info.applicationInfo;
             appInfo.publicSourceDir=apkPath;
             try {
                 return appInfo.loadLabel(pm).toString();
             } catch (OutOfMemoryError e) {
                 Log.e("ApkIconLoader", e.toString());
             }
         }
         return file.getName();
}

三。对drawable图片的缩放

static Drawable zoomDrawable(Drawable drawable, int w, int h)
     {
              int width = drawable.getIntrinsicWidth();
              int height= drawable.getIntrinsicHeight();
               Bitmap oldbmp = drawableToBitmap(drawable,width,height); // drawable转换成bitmap
               Matrix matrix = new Matrix();   // 创建操作图片用的Matrix对象
              float scaleWidth = ((float)w / width);   // 计算缩放比例
              float scaleHeight = ((float)h / height);
               matrix.postScale(scaleWidth, scaleHeight);         // 设置缩放比例
               Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height, matrix, true);       // 建立新的bitmap，其内容是对原bitmap的缩放后的图
              return new BitmapDrawable(newbmp);       // 把bitmap转换成drawable并返回
     }

static Bitmap drawableToBitmap(Drawable drawable,int width, int height){
           Bitmap bitmap = Bitmap.createBitmap(width, height, drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888: Bitmap.Config.RGB_565);
           Canvas canvas = new Canvas(bitmap);
           drawable.setBounds(0,0,width,height);
           drawable.draw(canvas);
           return bitmap;

}

四。安装APK

  Intent intent = new Intent();
      intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.setAction(android.content.Intent.ACTION_VIEW);
    intent.setDataAndType(Uri.fromFile(file),"application/vnd.android.package-archive");
    startActivity(intent);

五，获取SD卡上视频文件列表

void getVideoList(){
   // List<VideoItem> items=new ArrayList<VideoItem>();
    ContentResolver mContentResolver = this.getContentResolver();
       Cursor cursor = mContentResolver.query(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, null,
               null, null, MediaStore.Video.DEFAULT_SORT_ORDER);
   if(cursor.moveToFirst()){
   do{
    VideoItem item=new VideoItem();

    int id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));

       //名称：MediaStore.Audio.Media.TITLE
       String tilte = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.TITLE));
       String type=cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.MIME_TYPE));

      String url = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA));

       int duration = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DURATION));
       item.id=id;
       item.duration=duration;
       item.path=url;
       item.type=type;
       item.videoName=tilte;
       item.bitmap=getVideoThumbnail(url, 100, 100, 1);
       items.add(item);
        Log.i("debug", "title"+tilte+"duration"+duration);
     }while(cursor.moveToNext());
   }
   }

5.获取视频文件的缩略图

private Bitmap getVideoThumbnail(String videoPath, int width, int height,
           int kind) {
        Bitmap bitmap = null;
        // 获取视频的缩略图
        bitmap = ThumbnailUtils.createVideoThumbnail(videoPath, kind);
        System.out.println("w"+bitmap.getWidth());
        System.out.println("h"+bitmap.getHeight());
        bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height,
                ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
        return bitmap;
    }

6.时间格式化

   protected String stringForTime(long timeMs) {
    mFormatBuilder=new StringBuilder();
    mFormatter=new Formatter();

        long totalSeconds = timeMs / 1000;

        long seconds = totalSeconds % 60;
        long minutes = (totalSeconds / 60) % 60;
        long hours   = totalSeconds / 3600;

        mFormatBuilder.setLength(0);
        if (hours > 0) {
            return mFormatter.format("%d:%02d:%02d", hours, minutes, seconds).toString();
        } else {
            return mFormatter.format("%02d:%02d", minutes, seconds).toString();
        }
    }