Android程序運行權限申請

如果系統版本爲5.1或5.1之前的版本，系統會要求用戶在安裝應用時允許相應的權限，如果
是6.0及6.0之後的系統版本，則會在應用運行時向用戶請求權限。

一、判斷該界面是否擁有該權限：

// Assume thisActivity is the current activity
int permissionCheck = ContextCompat.checkSelfPermission(thisActivity,
        Manifest.permission.WRITE_CALENDAR);

如果程序擁有這個權限，則返回 PackageManager.PERMISSION_GRANTED，否則返回 PERMISSION_DENIED，此時程序需要向用戶申請權限。

具體示例：

// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.READ_CONTACTS)) {

        // Show an expanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
}

權限請求發出後，系統會向用戶展示一個對話框，當用戶響應請求之後，系統會調用onRequestPermissionsResult() 方法，攜帶用戶響應信息，
你必須複寫該方法以確定是否獲得權限，如：

@Override
public void onRequestPermissionsResult(int requestCode,
        String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the
                // contacts-related task you need to do.

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request
    }
}

注：requestCode是你在請求權限調用requestPermissions(）方法時傳入的請求碼。