Android程序安装和卸载

安装：

String str = "/CanavaCancel.apk";
String fileName = Environment.getExternalStorageDirectory() + str;
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(fileName)), "application/vnd.android.package-archive");
startActivity(intent);

卸载：

Uri packageURI = Uri.parse("package:com.demo.CanavaCancel");
Intent uninstallIntent = new Intent(Intent.ACTION_DELETE, packageURI);
startActivity(uninstallIntent);

Environment拥有一些可以获取环境变量的方法

package:com.demo.CanavaCancel 这个形式是 package:程序完整的路径 (包名+程序名).

//下载apk程序代码

protected File downLoadFile(String httpUrl) {
final String fileName = "updata.apk";
File tmpFile = new File("/sdcard/update");
if (!tmpFile.exists()) {
tmpFile.mkdir();
}
final File file = new File("/sdcard/update/" + fileName);

try {
URL url = new URL(httpUrl);
try {
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStream is = conn.getInputStream();
FileOutputStream fos = new FileOutputStream(file);
byte[] buf = new byte[256];
conn.connect();
double count = 0;
if (conn.getResponseCode() >= 400) {
Toast.makeText(Main.this, "连接超时", Toast.LENGTH_SHORT).show();
} else {
while (count <= 100) {
if (is != null) {
int numRead = is.read(buf);
if (numRead <= 0) {
break;
} else {
fos.write(buf, 0, numRead);
}

} else {
break;
}

}
}
conn.disconnect();
fos.close();
is.close();
} catch (IOException e) {

e.printStackTrace();
}
} catch (MalformedURLException e) {
e.printStackTrace();
}

return file;
}

//打开APK程序代码

private void openFile(File file) {
// TODO Auto-generated method stub
Log.e("OpenFile", file.getName());
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);
}

备注说明：

Android系统的应用安装，在系统设置里面有一项，是否安装未知源，所在在软件更新的时候，需要检测这个选项，如果打钩，则只允许安装Market源提供的安装程序，如果没有打钩的话，系统安装应用时会提示用户设置，如果选择设置，设置好后，无法返回安装界面；如果选择取消，则推出安装程序。所以，如果是更新的话，一定要在下载之前就检测许可安装源的设置，或者在下载前检测是否已经下载过新的安装程序，避免重复下载安装程序。

相关的代码如下

int result = Settings.Secure.getInt(getContentResolver(), Settings.Secure.INSTALL_NON_MARKET_APPS, 0);

if (result == 0) {

// show some dialog here

// ...

// and may be show application settings dialog manually

Intent intent = new Intent();

intent.setAction(Settings.ACTION_APPLICATION_SETTINGS);

startActivity(intent);

}