ldpi,mdpi,hdpi,xhdpi,xxhdpi,xxxhdpi

ldpi,mdpi,hdpi,xhdpi,xxhdpi,xxxhdpi

float xdpi = getResources().getDisplayMetrics().xdpi;
float ydpi = getResources().getDisplayMetrics().ydpi;

https://blog.csdn.net/guolin_blog/article/details/50727753
https://developer.android.com/reference/android/util/DisplayMetrics.html

AboutDialog の追加

AboutDialog の追加

    public class AboutDialog extends AlertDialog {
        private Context context;

        public AboutDialog(Context context) {
            super(context);
            this.context = context;
        }

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            LinearLayout li = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.about_layout, null);
            TextView textView = li.findViewById(R.id.textView3);
            textView.setText(Html.fromHtml("<u>" + getString(R.string.GooglePlayStore) + "<u>"));
            Pattern pattern = Pattern.compile("");
            String url = getString(R.string.PlayURL);
            Linkify.addLinks(textView, pattern, url, null, null);
            setContentView(li);
        }
    }



<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingLeft="20dp"
    android:paddingTop="10dp"
    android:paddingRight="20dp"
    android:paddingBottom="30dp">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        app:srcCompat="@mipmap/ic_launcher_foreground" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="20dp"
        android:layout_weight="1"
        android:text="@string/app_name"
        android:textSize="30dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="20dp"
        android:layout_weight="1"
        android:text="@string/kankanla"
        android:textSize="20dp" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="20dp"
        android:layout_weight="1"
        android:text="@string/GooglePlayStore"
        android:textSize="20dp" />
</LinearLayout>

Ads SDK

    ******************************************************************************
    * The Google Mobile Ads SDK was initialized incorrectly. AdMob publishers    *
    * should follow the instructions here: https://goo.gl/fQ2neu to add a valid  *
    * App ID inside the AndroidManifest. Google Ad Manager publishers should     *
    * follow instructions here: https://goo.gl/h17b6x.                           *
    ******************************************************************************

3.5 毫米耳机：配件规范

3.5 毫米耳机：配件规范



https://source.android.com/devices/accessories/headset/plug-headset-spec

直接启动

直接启动

<action android:name="android.intent.action.LOCKED_BOOT_COMPLETED" />

https://developer.android.com/training/articles/direct-boot?hl=zh-cn

アルファベットArrayList作成

import java.util.*;

class chart {
public static void main(String[] args) {
ArrayList<String> keyList = new ArrayList<>();
for (int i = 0x41; i < 0x5B; i++) {
keyList.add(String.valueOf((char)i));
}

for (int i = 0x30; i < 0x3A; i++) {
keyList.add(String.valueOf((char)i));
}

System.out.println(keyList);


String x = keyList.toString();
char[] temp = x.toCharArray();
temp = x.toCharArray();
for (char cc : temp) {
System.out.println(cc);
}

StringBuffer temp2 = new StringBuffer();

for(String xx :keyList){
temp2.append(xx);
}

System.out.println(temp2);
}
}

【Android】快速切换到主线程更新UI的几种方法

【Android】快速切换到主线程更新UI的几种方法
方法一： view.post(Runnable action)
textView.post(new Runnable() {
        @Override
        public void run() {
            textView.setText("更新textView");
            //还可以更新其他的控件
            imageView.setBackgroundResource(R.drawable.update);
        }
    });

方法二： activity.runOnUiThread(Runnable action)
public void updateUI(final Context context) {
        ((MainActivity) context).runOnUiThread(new Runnable() {
            @Override
            public void run() {
                //此时已在主线程中，可以更新UI了
            }
        });
    }

方法三： Handler机制
...