工具代码整理_5

一、获取应用程序下所有Activity



public static ArrayList<String> getActivities(Context ctx) {

ArrayList<String> result = new ArrayList<String>();

Intent intent = new Intent(Intent.ACTION_MAIN, null);

intent.setPackage(ctx.getPackageName());

for (ResolveInfo info : ctx.getPackageManager().queryIntentActivities(intent, 0)) {

result.add(info.activityInfo.name);

}

return result;

}



二、检测字符串中是否包含汉字



public static boolean checkChinese(String sequence) {

final String format = "[\\u4E00-\\u9FA5\\uF900-\\uFA2D]";

boolean result = false;

Pattern pattern = Pattern.compile(format);

Matcher matcher = pattern.matcher(sequence);

result = matcher.find();

return result;

}



三、检测字符串中只能包含：中文、数字、下划线(_)、横线(-)

public static boolean checkNickname(String sequence) {

final String format = "[^\\u4E00-\\u9FA5\\uF900-\\uFA2D\\w-_]";

Pattern pattern = Pattern.compile(format);

Matcher matcher = pattern.matcher(sequence);

return !matcher.find();

}

四、检查有没有应用程序来接受处理你发出的intent

publicstatic boolean isIntentAvailable(Context context, String action) {
final PackageManager packageManager = context.getPackageManager();
final Intent intent = new Intent(action);
List<ResolveInfo> list = packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
return list.size() > 0;
}

五、使用TransitionDrawable实现渐变效果



private void setImageBitmap(ImageView imageView, Bitmap bitmap) {

// Use TransitionDrawable to fade in.

final TransitionDrawable td = new TransitionDrawable(new Drawable[] { new ColorDrawable(android.R.color.transparent), new BitmapDrawable(mContext.getResources(), bitmap) });

//noinspection deprecation

imageView.setBackgroundDrawable(imageView.getDrawable());

imageView.setImageDrawable(td);

td.startTransition(200);

}



比使用AlphaAnimation效果要好，可避免出现闪烁问题。

六、 扫描指定的文件

sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri));

用途：从本软件新增、修改、删除图片、文件某一个文件（音频、视频）需要更新系统媒体库时使用，不必扫描整个SD卡。

七、Dip转px

public static int dipToPX(final Context ctx, float dip) {

return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip, ctx.getResources().getDisplayMetrics());

}