请帮我解决这个问题。 我是Android Studio的新手。 我的代码一点错误都没有，但是我不知道为什么我的app每次启动都不停地崩溃。 请帮助我，我需要这个为我的项目。 谢谢。
这是我的日志猫中出现的内容
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mmtravelapp/com.example.mmtravelapp.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
这是我的主要活动。java
public class MainActivity extends AppCompatActivity {
private DatabaseHelper dbHelper;
private ImageView pImageView;
private EditText Pemail, Pname, PAge, Pphone, Ppassword;
private TextView loginacclink, Ppreferenceselected;
Button createacc, preferencebtn;
ActionBar actionBar;
String[] categories;
boolean[] checkeditems;
ArrayList<Integer> mUserItems = new ArrayList<>();
private static final int CAMERA_REQUEST_CODE = 100;
private static final int STORAGE_REQUEST_CODE = 101;
private static final int IMAGE_PICK_CAMERA_CODE = 102;
private static final int IMAGE_PICK_GALLERY_CODE = 103;
private String[] cameraPermissions;
private String[] storagePermissions;
private Uri imageUri;
private String name, age, phone,email, password;
private String preferenceselected;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// this is the status bar
actionBar = getSupportActionBar();
actionBar.setTitle("Create Account");
// this is for the check list
categories = getResources().getStringArray(R.array.user_categories);
checkeditems = new boolean[categories.length];
// this is for the items in the xml file
pImageView = findViewById(R.id.personImage);
Pemail = findViewById(R.id.email);
Pname = findViewById(R.id.name);
PAge = findViewById(R.id.age);
Pphone = findViewById(R.id.phone);
Ppassword = findViewById(R.id.password);
createacc = findViewById(R.id.createacc);
preferencebtn = findViewById(R.id.preferencebtn);
loginacclink = findViewById(R.id.loginacclink);
pImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
imagePickDialog();
}
});
preferencebtn.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick (View view){
AlertDialog.Builder mBuilder = new AlertDialog.Builder(MainActivity.this);
mBuilder.setTitle(R.string.dialog_title);
mBuilder.setMultiChoiceItems(categories, checkeditems, new DialogInterface.OnMultiChoiceClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int position, boolean isChecked) {
if (isChecked) {
if (!mUserItems.contains(position)) {
mUserItems.add(position);
}
} else if (mUserItems.contains(position)) {
mUserItems.remove(position);
}
}
});
mBuilder.setCancelable(false);
mBuilder.setPositiveButton(R.string.ok_label, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int which) {
String item = "";
for (int i = 0; i < mUserItems.size(); i++) {
item = item + categories[mUserItems.get(i)];
if (i != mUserItems.size() - 1) {
item = item + ",";
}
}
Ppreferenceselected.setText(item);
}
});
mBuilder.setNegativeButton(R.string.dismiss_label, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.dismiss();
}
});
mBuilder.setNeutralButton(R.string.clear_all_label, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int which) {
for (int i = 0; i < checkeditems.length; i++) {
checkeditems[i] = false;
mUserItems.clear();
Ppreferenceselected.setText("");
}
}
});
AlertDialog mDialog = mBuilder.create();
mDialog.show();
}
});
loginacclink.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this, login.class);
startActivity(intent); }
});
Ppreferenceselected = (TextView) findViewById(R.id.preferenceselected);
dbHelper = new DatabaseHelper(this);
cameraPermissions = new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE};
storagePermissions = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};
createacc.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// insert data into db
getData();
}
});
}
private void getData() {
email = "" + Pemail.getText().toString().trim();
name = "" + Pname.getText().toString().trim();
age = "" + PAge.getText().toString().trim();
phone = "" + Pphone.getText().toString().trim();
preferenceselected = "" + Ppreferenceselected.getText().toString().trim();
password = "" + Ppassword.getText().toString().trim();
if (email.isEmpty() || name.isEmpty() || age.isEmpty() || phone.isEmpty() || preferenceselected.isEmpty() || password.isEmpty()) {
Toast.makeText(this, "Please fill all the information", Toast.LENGTH_SHORT).show();
return;
}
if (dbHelper.userExists(email)){
Toast.makeText(this, "User Exist", Toast.LENGTH_SHORT).show();
return;
}
String timeStamp = "" + System.currentTimeMillis();
boolean id = dbHelper.insertInfo(
"" + imageUri,
"" + email,
"" + name,
"" + age,
"" + phone,
"" + preferenceselected,
"" + password,
""+timeStamp,
""+timeStamp
);
Toast.makeText(this, "Account Created", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this, setting.class);
startActivity(intent);
}
private void imagePickDialog() {
String[] options = {"Camera", "Gallery"};
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Pick Image From");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
if (which == 0) {
if (!checkCameraPermission()) {
requestCameraPermission();
}
else {
pickFromCamera();
}
}
else if (which == 1) {
if (!checkStoragePermission()) {
requestStoragePermission();
}
else {
pickFromGallery();
}
}
}
});
builder.create().show();
}
private boolean checkCameraPermission() {
boolean result = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
== (PackageManager.PERMISSION_GRANTED);
boolean result1 = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
== (PackageManager.PERMISSION_GRANTED);
return result && result1;
}
private void requestCameraPermission() {
ActivityCompat.requestPermissions(this, cameraPermissions, CAMERA_REQUEST_CODE);
}
private void pickFromGallery() {
Intent galleryIntent = new Intent(Intent.ACTION_PICK);
galleryIntent.setType("image/*");
startActivityForResult(galleryIntent, IMAGE_PICK_GALLERY_CODE);
}
private void pickFromCamera() {
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.TITLE, "Image title");
values.put(MediaStore.Images.Media.DESCRIPTION, "Image description");
imageUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(cameraIntent, IMAGE_PICK_CAMERA_CODE);
}
private boolean checkStoragePermission() {
boolean result = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
== (PackageManager.PERMISSION_GRANTED);
return result;
}
private void requestStoragePermission() {
ActivityCompat.requestPermissions(this, storagePermissions, STORAGE_REQUEST_CODE);
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case CAMERA_REQUEST_CODE: {
if (grantResults.length>0) {
boolean cameraAccepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
boolean storageAccepted = grantResults[1] == PackageManager.PERMISSION_GRANTED;
if (cameraAccepted && storageAccepted) {
pickFromCamera();
}
else {
Toast.makeText(this, "Camera permission required!", Toast.LENGTH_SHORT).show();
}
}
}
break;
case STORAGE_REQUEST_CODE:{
if (grantResults.length>0) {
boolean storageAccepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
if (storageAccepted) {
pickFromGallery();
}
else {
Toast.makeText(this, "Storage permission required!", Toast.LENGTH_SHORT).show();
}
}
}
break;
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
if (resultCode == RESULT_OK) {
if (requestCode == IMAGE_PICK_GALLERY_CODE) {
CropImage.activity(data.getData())
.setGuidelines(CropImageView.Guidelines.ON)
.setAspectRatio(1, 1)
.start(this);
}
else if (requestCode == IMAGE_PICK_CAMERA_CODE) {
CropImage.activity(imageUri)
.setGuidelines(CropImageView.Guidelines.ON)
.setAspectRatio(1, 1)
.start(this);
}
else if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE) {
CropImage.ActivityResult result = CropImage.getActivityResult(data);
if (resultCode == RESULT_OK) {
Uri resultUri = result.getUri();
imageUri = resultUri;
pImageView.setImageURI(resultUri);
}
else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE) {
Exception error = result.getError();
Toast.makeText(this, ""+error, Toast.LENGTH_SHORT).show();
}
}
}
super.onActivityResult(requestCode, resultCode, data);
}
}
这是我的res/values/styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
</resources>
提前感谢您的帮助！
您需要将theme.AppCompat主题（或后代）与此activity一起使用。
打开AndroidManifest.xml并查找MainActivity。 如果没有android:theme属性，就意味着activity正在使用该应用主题。 打开它并检查父属性是否是theme.appcompat可用的属性之一。 例如:
<style name="YourAppTheme" parent="Theme.AppCompat.Light"></style>
