所以我已经完全重写了请求权限的代码。现在它支持请求多个权限并以正确的结果运行代码。它也适用于 preMarshmallow 设备，因此在这种情况下您不必检查和复制代码。
首先，使用此代码创建一个 Activity 类（您可以扩展您需要的任何活动之王，例如 AppCompatActivity）：
public abstract class PermissionActivity extends AppCompatActivity {
private final ArrayList<PermissionListener> permissionListeners = new ArrayList<>();
@SuppressWarnings("unused")
public void requestPermissions(int requestCode, String[] requestPermissions, PermissionListener permissionListener) {
requestPermissions(requestCode, requestPermissions, null, permissionListener);
}
@SuppressWarnings("unused")
public void requestPermissions(final int requestCode, String[] requestPermissions, String message, final PermissionListener permissionListener) {
final int[] grantResults = new int[requestPermissions.length];
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
ArrayList<String> list_notGranted = new ArrayList<>();
for (String requestPermission : requestPermissions)
if (ContextCompat.checkSelfPermission(this, requestPermission) != PackageManager.PERMISSION_GRANTED)
list_notGranted.add(requestPermission);
if (list_notGranted.size() > 0) {
permissionListeners.add(permissionListener);
requestPermissions = list_notGranted.toArray(new String[list_notGranted.size()]);
if (message != null) {
boolean shouldShowRequestPermissionRationale = false;
for (String permission : requestPermissions)
if (ActivityCompat.shouldShowRequestPermissionRationale(this, permission)) {
shouldShowRequestPermissionRationale = true;
break;
}
if (shouldShowRequestPermissionRationale) {
final String[] f_requestPermissions = requestPermissions;
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(message);
DialogInterface.OnClickListener onClickListener = new DialogInterface.OnClickListener() {
@TargetApi(Build.VERSION_CODES.M)
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case DialogInterface.BUTTON_POSITIVE:
PermissionActivity.super.requestPermissions(f_requestPermissions, requestCode);
break;
default:
for (int i = 0; i < grantResults.length; i++)
grantResults[i] = PackageManager.PERMISSION_DENIED;
if (permissionListener != null)
permissionListener.onResult(requestCode, f_requestPermissions, grantResults);
break;
}
}
};
builder.setPositiveButton("OK", onClickListener);
builder.setNegativeButton("Cancel", onClickListener);
builder.show();
} else {
super.requestPermissions(requestPermissions, requestCode);
}
} else {
super.requestPermissions(requestPermissions, requestCode);
}
} else {
for (int i = 0; i < grantResults.length; i++)
grantResults[i] = PackageManager.PERMISSION_GRANTED;
if (permissionListener != null)
permissionListener.onResult(requestCode, requestPermissions, grantResults);
}
} else {
if (permissionListener != null) {
for (int i = 0; i < grantResults.length; i++)
grantResults[i] = PackageManager.PERMISSION_GRANTED;
permissionListener.onResult(requestCode, requestPermissions, grantResults);
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
for (Iterator<PermissionListener> it = permissionListeners.iterator(); it.hasNext(); ) {
PermissionListener permissionListener = it.next();
if (permissionListener.onResult(requestCode, permissions, grantResults)) {
it.remove();
}
}
}
public interface PermissionListener {
boolean onResult(int requestCode, String[] requestPermissions, int[] grantResults);
}
}
如果你想从 Fragments 请求权限，添加这个类：
public class PermissionFragment extends Fragment {
@SuppressWarnings("unused")
public void requestPermissions(int requestCode, String[] requestPermissions, PermissionActivity.PermissionListener permissionListener) {
requestPermissions(requestCode, requestPermissions, null, permissionListener);
}
@SuppressWarnings("unused")
public void requestPermissions(final int requestCode, String[] requestPermissions, String message, PermissionActivity.PermissionListener permissionListener) {
((PermissionActivity) getActivity()).requestPermissions(requestCode, requestPermissions, message, permissionListener);
}
}
您的活动和片段应该扩展这些类而不是标准类。
现在您可以通过调用方法来请求权限：
requestPermissions(int requestCode, String[] requestPermissions, PermissionListener permissionListener)
如果应用程序需要权限才能运行，您应该调用此方法并指定消息说明为什么需要权限。
requestPermissions(int requestCode, String[] requestPermissions, String message, PermissionListener permissionListener)
不要错误调用默认方法，即
// DON'T USE THIS ONE!
requestPermissions(String[] requestPermissions, int requestCode)
// DON'T USE THIS ONE!
以下是请求联系人的示例：
private void requestAndLoadContacts() {
String[] permissions = new String[]{Manifest.permission.READ_CONTACTS};
requestPermissions(REQUEST_PERMISSIONS_CONTACTS, permissions, "Read contacts permission is required for the app to work!", new PermissionListener() {
@Override
public boolean onResult(int requestCode, String[] requestPermissions, int[] grantResults) {
// Check if the requestCode is ours
if (requestCode == REQUEST_PERMISSIONS_CONTACTS) {
// Check if the permission is correct and is granted
if (requestPermissions[0].equals(Manifest.permission.READ_CONTACTS) && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission granted
// Calling a method to actually load the contacts
loadContacts();
} else {
// Permission not granted
Toast.makeText(MainActivity.this, "Access denied!", Toast.LENGTH_SHORT).show();
}
return true;
}
return false;
}
});
}
注意：当你实现 PermissionListener 时，不要忘记在requestCode 是正确的时候返回 true，否则 PermissionListener不会从 ArrayList 中删除，你很可能会得到一个小的内存泄漏。