Are package names and class names easy to crash? With the signature file, all these can be solved well. If APK is signed with a key, a file signed with another key will not be able to install or overwrite the old version when it is published, which can prevent your installed application from being overwritten or replaced by a malicious third party. For example, if you release an application in the electronic market, you need to upgrade the application after a period of time and continue to use your previous signature file, so as to ensure your copyright and security. The Tao is one foot high, and the devil is ten feet high. On China's screen, Niu B's software may also be cracked. With a signed document, this kind of thing can be well prevented (not completely prevented). This signature is actually the identity of the developer. When something such as denial occurs in the transaction, signature can prevent the occurrence of denial. All the above points are the advantages of using signature files. Not all of them, but they are common and typical. In fact, the APK file that we installed from the development environment to the mobile phone using Eclipse+ADT plug-in already contains the debugging signature file of ADT plug-in. But this is not an official signature document at the time of publication. Readers can refer to my specific steps above and try to publish their own app, and please keep the signature file. After signing, you can use winrar to open apk and CERT. RSA file with text editor in Meta-inf directory. If you can see some text you entered when building the key, it will be officially signed. If you sign the test, the word debug will appear. (Generally, the code will be garbled, but it can be seen clearly by the naked eye. It is worth reminding that after the software code is updated (a new APK needs to be released), the android:versionCode value of Manifest should be+1, and 1 should be added every time it is updated. Knowing this, it's time to talk about uploading applications. Because Android is a relatively open platform, the restrictions on uploading applications are also low, and there is no official specification. Not as closed as Apple and its app store. There are many websites that upload applications in China, and the most famous one in China is the Android market. Different market audit rules are different, but there are similarities. There are also some noteworthy things: pay attention to your APP language (internationalization), screen resolution and size support ... (of course, this should be done before packaging) Original source = = = = = = A better way to enter the signature folder jarsigner in CMD? Verifyhhello.apk shows whether the signature has been successfully verified as follows.