Question

我试图让我的微调器菜单通过改变任何颜色来响应。无法改变任何颜色。选择绿色之前和之后看图片。我正在学习如何为Android编程。

这是我的MainActivity.java

C:\Users\USER\Desktop> my_executable arg1 '"A>200 && B<300 (just some conditions"'

这是我的activity_main.xml

package com.romanescotech.mydropdownnavigation;

import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.SpinnerAdapter;

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {

Spinner spinner;
ArrayAdapter adapter;
Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
    spinner = (Spinner) findViewById(R.id.spinnerMy);
    adapter = ArrayAdapter.createFromResource(this, R.array.colors, R.layout.support_simple_spinner_dropdown_item);
    adapter.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
@Override
public void onItemSelected(AdapterView<?> parent , View view, int pos, long id) {
    parent.getItemAtPosition(pos);
    String[] colors = getResources().getStringArray(R.array.colors);
    String selectedColor = colors[pos];
    getWindow().getDecorView().setBackgroundColor(Color.parseColor(selectedColor));
    spinner.setBackgroundColor(Color.parseColor(selectedColor));
    view.setBackgroundColor(Color.parseColor(selectedColor));



}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// do nothing
}
}

<?xml version="1.0" encoding="utf-8"?>

这是我的string.xml

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

    <Spinner
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/spinnerMy"
        android:alpha=".8" />


</android.support.design.widget.AppBarLayout>

<include layout="@layout/content_main" />

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|end"
    android:layout_margin="@dimen/fab_margin"
    app:srcCompat="@android:drawable/ic_dialog_email" />

这是我的清单文件

<resources>
<string name="app_name">MyDropDownNavigation</string>
<string-array name="colors">
    <item>White</item>
    <item>Red</item>
    <item>Green</item>
    <item>Blue</item>
    <item>Yellow</item>
</string-array>
<string name="action_settings">Settings</string>

<?xml version="1.0" encoding="utf-8"?>

这是我的styles.xml

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

这是我的其他v21 / 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>

<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

这是在选择之前运行的图片 before making selection

这是在选择之后，manues，背景一切都是相同的颜色。

after making selection

我猜我的问题在于这种方法。

<resources>

<style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
    <item name="android:windowDrawsSystemBarBackgrounds">true</item>
    <item name="android:statusBarColor">@android:color/transparent</item>
</style>

在java代码中

Answer 1

除了一次更改外，您的程序看起来是正确的。视图更改后，您需要通知，以便视图了解已发生的更改并在UI中反映它。尝试在方法 onItemSelected（）的末尾调用 adapter.notifydatasetchanged 。

希望它对你有所帮助。

无法从微调器菜单中获取任何更改颜色的内容

1 个答案: