创建分享
- 创建Intent并指定Action为Intent.ACTION_SEND。
val shareIntent = Intent(Intent.ACTION_SEND)
- 指定需要发送的内容和类型。
//传输文件 采用流的方式
intent.putExtra(Intent.EXTRA_STREAM,Uri.fromFile(File(fileUrl))
intent.type = "*/*"
- 发送隐式意图，打开系统分享选择器。
context.startActivity(shareIntent)
获取文件类型（MimeType）
文件分享时一般都要设置好文件类型，默认指定类型为*/*，已默认类型进行分享时有些App不支持这种类型，会导致我们分享失败，最好的方式是预先根据文件路径设置好文件类型。
常见文件的mimeType
{".3gp", "video/3gpp"},
{".apk", "application/vnd.android.package-archive"},
{".asf", "video/x-ms-asf"},
{".avi", "video/x-msvideo"},
{".bin", "application/octet-stream"},
{".bmp", "image/bmp"},
{".c", "text/plain"},
{".class", "application/octet-stream"},
{".conf", "text/plain"},
{".cpp", "text/plain"},
{".doc", "application/msword"},
{".exe", "application/octet-stream"},
{".gif", "image/gif"},
{".gtar", "application/x-gtar"},
{".gz", "application/x-gzip"},
{".h", "text/plain"},
{".htm", "text/html"},
{".html", "text/html"},
{".jar", "application/java-archive"},
{".java", "text/plain"},
{".jpeg", "image/jpeg"},
{".jpg", "image/jpeg"},
{".js", "application/x-javascript"},
{".log", "text/plain"},
{".m3u", "audio/x-mpegurl"},
{".m4a", "audio/mp4a-latm"},
{".m4b", "audio/mp4a-latm"},
{".m4p", "audio/mp4a-latm"},
{".m4u", "video/vnd.mpegurl"},
{".m4v", "video/x-m4v"},
{".mov", "video/quicktime"},
{".mp2", "audio/x-mpeg"},
{".mp3", "audio/x-mpeg"},
{".mp4", "video/mp4"},
{".mpc", "application/vnd.mpohun.certificate"},
{".mpe", "video/mpeg"},
{".mpeg", "video/mpeg"},
{".mpg", "video/mpeg"},
{".mpg4", "video/mp4"},
{".mpga", "audio/mpeg"},
{".msg", "application/vnd.ms-outlook"},
{".ogg", "audio/ogg"},
{".pdf", "application/pdf"},
{".png", "image/png"},
{".pps", "application/vnd.ms-powerpoint"},
{".ppt", "application/vnd.ms-powerpoint"},
{".prop", "text/plain"},
{".rar", "application/x-rar-compressed"},
{".rc", "text/plain"},
{".rmvb", "audio/x-pn-realaudio"},
{".rtf", "application/rtf"},
{".sh", "text/plain"},
{".tar", "application/x-tar"},
{".tgz", "application/x-compressed"},
{".txt", "text/plain"},
{".wav", "audio/x-wav"},
{".wma", "audio/x-ms-wma"},
{".wmv", "audio/x-ms-wmv"},
{".wps", "application/vnd.ms-works"},
{".xml", "text/xml"},
{".xml", "text/plain"},
{".z", "application/x-compress"},
{".zip", "application/zip"},
{"", "*/*"}
方式一：通过 ContentResolver 查询 Android 系统提供的 ContentProvider 获取（方便但不稳定）
当 targetSdkVersion >= 24 时，
使用 Uri.fromFile(File file) 获取文件 URI 会报android.os.FileUriExposedException 异常
- 获取文件的 url
val shareFile = File(shareFilePath)
val fileUri = Uri.fromFile(shareFile)
- 获取系统的提供的 ContentResolver
val contentResolver = context!!.contentResolver
- 获取文件MimeType，如 image/png
val fileMimeType = contentResolver.getType(fileUri)
- 获取文件Type，如 txt
val mime = MimeTypeMap.getSingleton()
val fileType = mime.getExtensionFromMimeType(fileMimeType)
方式二：解析文件信息，通过匹配识别判断：
- 识别文件后缀，根据后缀名来判断文件类型。
- 获取文件头信息，转成十六进制字符串后判断文件类型。
object FileUtil {
/**
* 根据文件后缀回去MIME类型
*
* @param file file
* @return string
*/
public fun getMIMEType(file: File): String {
var type = "*/*"
val fName = file.name
//获取后缀名前的分隔符"."在fName中的位置。
val dotIndex = fName.lastIndexOf(".")
if (dotIndex < 0) {
return type
}
/* 获取文件的后缀名*/
val end = fName.substring(dotIndex, fName.length).toLowerCase()
if (TextUtils.isEmpty(end)) {
return type
}
//在MIME和文件类型的匹配表中找到对应的MIME类型。
for (i in MIME_MapTable.indices) {
if (end == MIME_MapTable[i][0]) {
type = MIME_MapTable[i][1]
break
}
}
return type
}
private val MIME_MapTable = arrayOf(
// {后缀名，MIME类型}
arrayOf(".3gp", "video/3gpp"),
arrayOf(".apk", "application/vnd.android.package-archive"),
arrayOf(".asf", "video/x-ms-asf"),
arrayOf(".avi", "video/x-msvideo"),
arrayOf(".bin", "application/octet-stream"),
arrayOf(".bmp", "image/bmp"),
arrayOf(".c", "text/plain"),
arrayOf(".class", "application/octet-stream"),
arrayOf(".conf", "text/plain"),
arrayOf(".cpp", "text/plain"),
arrayOf(".doc", "application/msword"),
arrayOf(".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
arrayOf(".xls", "application/vnd.ms-excel"),
arrayOf(".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"),
arrayOf(".exe", "application/octet-stream"),
arrayOf(".gif", "image/gif"),
arrayOf(".gtar", "application/x-gtar"),
arrayOf(".gz", "application/x-gzip"),
arrayOf(".h", "text/plain"),
arrayOf(".htm", "text/html"),
arrayOf(".html", "text/html"),
arrayOf(".jar", "application/java-archive"),
arrayOf(".java", "text/plain"),
arrayOf(".jpeg", "image/jpeg"),
arrayOf(".jpg", "image/jpeg"), arrayOf(".js", "application/x-javascript"), arrayOf(".log", "text/plain"),
arrayOf(".m3u", "audio/x-mpegurl"), arrayOf(".m4a", "audio/mp4a-latm"), arrayOf(".m4b", "audio/mp4a-latm"),
arrayOf(".m4p", "audio/mp4a-latm"), arrayOf(".m4u", "video/vnd.mpegurl"), arrayOf(".m4v", "video/x-m4v"), arrayOf(".mov", "video/quicktime"),
arrayOf(".mp2", "audio/x-mpeg"), arrayOf(".mp3", "audio/x-mpeg"), arrayOf(".mp4", "video/mp4"),
arrayOf(".mpc", "application/vnd.mpohun.certificate"), arrayOf(".mpe", "video/mpeg"), arrayOf(".mpeg", "video/mpeg"),
arrayOf(".mpg", "video/mpeg"), arrayOf(".mpg4", "video/mp4"), arrayOf(".mpga", "audio/mpeg"), arrayOf(".msg", "application/vnd.ms-outlook"),
arrayOf(".ogg", "audio/ogg"),
arrayOf(".pdf", "application/pdf"), arrayOf(".png", "image/png"), arrayOf(".pps", "application/vnd.ms-powerpoint"),
arrayOf(".ppt", "application/vnd.ms-powerpoint"), arrayOf(".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"),
arrayOf(".prop", "text/plain"),
arrayOf(".rc", "text/plain"), arrayOf(".rmvb", "audio/x-pn-realaudio"), arrayOf(".rtf", "application/rtf"),
arrayOf(".sh", "text/plain"),
arrayOf(".tar", "application/x-tar"), arrayOf(".tgz", "application/x-compressed"), arrayOf(".txt", "text/plain"),
arrayOf(".wav", "audio/x-wav"),
arrayOf(".wma", "audio/x-ms-wma"), arrayOf(".wmv", "audio/x-ms-wmv"), arrayOf(".wps", "application/vnd.ms-works"),
arrayOf(".xml", "text/plain"), arrayOf(".z", "application/x-compress"), arrayOf(".zip", "application/x-zip-compressed"), arrayOf("", "*/*"))
}
