Question

如何正确对齐图标？

这是我的活动主要xml，带有底部的应用栏和浮动操作按钮。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activities.MainActivity">

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <FrameLayout
            android:id="@+id/fragmentview"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <com.google.android.material.bottomappbar.BottomAppBar
            android:id="@+id/bottom_app_bar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            app:backgroundTint="@color/bluPrincipale"
            app:fabAlignmentMode="center"/>


        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_icona_menu_mappa"
            app:layout_anchor="@id/bottom_app_bar" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

这是我的主要活动，可以使我认为的片段有用。

MainActivity.java

package com.example.test.activities;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentTransaction;

import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

import com.example.test.R;
import com.example.test.fragments.ConvenzioniFragment;
import com.example.test.fragments.DoveAndareFragment;
import com.example.test.fragments.HomeFragment;
import com.example.test.fragments.MappaFragment;
import com.example.test.fragments.MoreFragment;
import com.google.android.material.bottomappbar.BottomAppBar;
import com.google.android.material.floatingactionbutton.FloatingActionButton;

public class MainActivity extends AppCompatActivity {

    private FloatingActionButton floatingActionButton;
    private BottomAppBar bottomAppBar;
    private boolean isFabTabbed = false;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        floatingActionButton = findViewById(R.id.fab);
        bottomAppBar = findViewById(R.id.bottom_app_bar);

        setSupportActionBar(bottomAppBar);

        if(savedInstanceState == null) {
            handleFrame(new HomeFragment());
        }

        handleFab();
    }

    private void handleFab() {
        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                isFabTabbed = !isFabTabbed;
                if(isFabTabbed) {
                    handleFrame(new MappaFragment());
                }
                else
                {
                    handleFrame(new HomeFragment());
                }
            }
        });
    }

    private void handleFrame(Fragment fragment) {
        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
        fragmentTransaction.setCustomAnimations(android.R.anim.slide_in_left, android.R.anim.slide_out_right);
        fragmentTransaction.replace(R.id.fragmentview, fragment);
        fragmentTransaction.commit();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        getMenuInflater().inflate(R.menu.bottomappbar_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {

        switch(item.getItemId()) {
            case R.id.app_bar_home:
                handleFrame(new HomeFragment());
                return true;
            case R.id.app_bar_dove_andare_sagre_eventi:
                handleFrame(new DoveAndareFragment());
                return true;
            case R.id.app_bar_convenzioni:
                handleFrame(new ConvenzioniFragment());
                return true;
            case R.id.app_bar_more:
                handleFrame(new MoreFragment());
                return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

这是我自定义的底部应用栏菜单。

bottomappbar_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <item
        android:id="@+id/app_bar_home"
        android:icon="@drawable/ic_icona_menu_home"
        android:title="Home"
        app:showAsAction="always"
       />

    <item
        android:id="@+id/app_bar_dove_andare_sagre_eventi"
        android:icon="@drawable/ic_icona_menu_dove_andare_sagre_eventi"
        android:title="Dove Andare"
        app:showAsAction="always"

       />
    <item
        android:id="@+id/app_bar_convenzioni"
        android:icon="@drawable/ic_icona_menu_convenzioni"
        android:title="Convenzioni"
        app:showAsAction="always"
        />

    <item
        android:id="@+id/app_bar_more"
        android:icon="@drawable/ic_icona_menu_more"
        android:title="More"
        app:showAsAction="always"
       />


</menu>

这是我的gradle代码。对我来说是正确的。

成绩

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.2"
    defaultConfig {
        applicationId "com.example.test"
        minSdkVersion 16
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.android.material:material:1.1.0-beta01'
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
}

但是底部的结果不是这样的：

picture correct

这是我的结果：|

mineresult

我正在使用最新的材料设计。

感谢您的帮助！克里斯

Answer 1

在您的课程中添加此代码，此代码必须解决您的对齐问题

 @SuppressLint("RestrictedApi")
    private void disableShiftMode(BottomNavigationView view) {
        BottomNavigationMenuView menuView = (BottomNavigationMenuView) view.getChildAt(0);
        try {
            Field shiftingMode = menuView.getClass().getDeclaredField("mShiftingMode");
            shiftingMode.setAccessible(true);
            shiftingMode.setBoolean(menuView, false);
            shiftingMode.setAccessible(false);
            for (int i = 0; i < menuView.getChildCount(); i++) {
                BottomNavigationItemView item = (BottomNavigationItemView) menuView.getChildAt(i);
                item.setShiftingMode(false);
                // set once again checked value, so view will be updated
                item.setChecked(item.getItemData().isChecked());
            }
        } catch (NoSuchFieldException e) {
            Log.e("BNVHelper", "Unable to get shift mode field", e);
        } catch (IllegalAccessException e) {
            Log.e("BNVHelper", "Unable to change value of shift mode", e);
        }
    }

Answer 2

从BottomAppBar删除菜单，并将其添加到BottomNavigationView中，然后在BottomNavigationView内添加BottomAppBar，如下所示：

<androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <FrameLayout
            android:id="@+id/fragmentview"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

        <com.google.android.material.bottomappbar.BottomAppBar
            android:id="@+id/bottom_app_bar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            app:fabAlignmentMode="center">
        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/bottomNavigationView"
            style="@style/MyBottomNavigationView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:itemIconTint="@color/selector_bottom_navigation"
            app:itemTextColor="@color/selector_bottom_navigation"
            app:labelVisibilityMode="labeled"
            app:menu="@menu/activity_home_bottom_nav" />
        </com.google.android.material.bottomappbar.BottomAppBar>

        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic__right_arrow"
            app:layout_anchor="@id/bottom_app_bar" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

如果执行此操作，则您的商品将按照您的期望显示在中间，但是您可能会遇到第二和第三商品的图标被FAB重叠，从而避免出现这种情况，在菜单中心添加一个空项目，如下所示：

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/itemRenewals"
        android:icon="@drawable/menu_renewals"
        android:title="Renewals" />

    <item
        android:id="@+id/itemViewOwner"
        android:icon="@drawable/menu_view_owner"
        android:title="View User" />

    <item
        android:id="@+id/itemEmpty"
        android:title=""/>

    <item
        android:id="@+id/itemEnquiry"
        android:icon="@drawable/menu_enquiry"
        android:title="Enquiry" />

    <item
        android:id="@+id/itemProfile"
        android:icon="@drawable/menu_profile"
        android:title="Profile" />
</menu>

BottomAppBar 4图标未正确对齐

2 个答案: