獲取當前app的簽名信息

    /**


 * get signature of current package 
 * @param context 
 * @return signature, null if there is no signature 
 */  
public static String getSignature(Context context){  

    Log.i(TAG, "SignatureUtils.getSignature");  

    PackageManager pm = context.getPackageManager();  
    String pkgName = context.getPackageName();  

    try {  
        PackageInfo pi = pm.getPackageInfo(pkgName, PackageManager.GET_SIGNATURES);  
        Signature[] signatures = pi.signatures;  

        if(signatures != null && signatures.length > 0){  

            String signature =  signatures[0].toCharsString();  
            Log.i(TAG, "Signature of current package is : " + signature);  

            return  signature;  
        }  
    } catch (PackageManager.NameNotFoundException e1) {  
        e1.printStackTrace();  
    }  

    return null;  
}  </pre>