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Die Anleitung zu Android Chronometer

  1. Android Chronometer
  2. Chronometer Methods
  3. Chronometer Events
  4. Example: Chronometer (Count up)
  5. Example: Chronometer (Count down)
  6. Example: Custom Format

1. Android Chronometer

In Android ist Chronometer ein Interface-Komponente, die einen einfachen Timer simuliert.
Hinweis: Die Komponente Chronometer ist in der Palette des Design-Fenster nicht verfügbar. Sie müssen daher den folgenden XML Code verwenden, um sie in die Interface hinzufügen.
<Chronometer
   android:id="@+id/simpleChronometer"
   android:countDown="false"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content" />

<Chronometer
   android:id="@+id/simpleChronometer"
   android:countDown="true"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content" />
android:countDown
Dieses Attribut gibt an, dass dieses Chronometer mit dem Wert true/false nach oben oder unten zählt (counts up or count down).
<!-- Counts Up -->
<Chronometer
   android:id="@+id/simpleChronometer"
   android:countDown="false"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content" />

<!-- Counts Down -->
<Chronometer
   android:id="@+id/simpleChronometer"
   android:countDown="true"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content" />
android:format
Dieses Attribut gibt eine Zeitformatzeichenfolge (time format string) für Chronometer an.
Standardmäßig zeigt Chronometer die Zeit im Format "MM:SS" an, wenn die Zeit weniger als 1 Stunde beträgt, oder "H:MM:SS" wenn die Zeit mehr als 1 Stunde beträgt. Der Wert des Attributs android:format muss im Form von "Text1 %s Text2" vorliegen. Wenn Chronometer die Uhrzeit anzeigt, erhalten Sie eine Zeichenfolge mit dem Format "Text1 MM:SS Text2" oder "Text1 H:MM:SS Text2".

2. Chronometer Methods

Chronometer Methods
long getBase()

void setBase(long base)

String getFormat()

void setFormat(String format)

boolean isCountDown()

void setCountDown(boolean countDown)

boolean isTheFinalCountDown()

void start()

void stop()
setBase(long base)
Diese Methode ist nur für die nach oben zählenden Chronometer (count up) nützlich, mit dem die Zeit eingestellt wird, auf die sich der Chronometer bezieht (entsprechend dem Wert von 00:00).
Der Parameter base ist die Anzahl der Milisekunden seit dem Start des Systems, einschlielich der Ruhestand des Gerät. Wenn Sie einen Android Emulator (der Emulator vom Android) verwenden, wird der Zeitpunkt des Starts des Computer als Ursprung der Koordinaten angesehen.
// Returns milliseconds since system boot, including time spent in sleep.
long elapsedRealtime = SystemClock.elapsedRealtime();

// Set the time that the count-up timer is in reference to.
this.chronometer.setBase(elapsedRealtime);

this.chronometer.start();
setFormat(String format)
Standardmäßig zeigt Chronometer die Zeit im Format "MM:SS" an, wenn die Zeit weniger als 01 Stunde beträgt, oder "H:MM:SS" wenn dei Zeit mehr als 1 Stunde beträgt. Der Wert des Parameter format muss in Form "Text1 %s Text2" vorliegen. Wenn Chronometer die Uhrzeit anzeigt, erhalten Sie eine Zeichenfolge mit dem Format "Text1 MM:SS Text2" oder "Text1 H:MM:SS Text2".
Wenn Sie das Zeitanzeigeformat Chronometer genauer anpassen möchten, lesen Sie das Beispiel am Ende dieses Artikels.

3. Chronometer Events

  • TODO

4. Example: Chronometer (Count up)

Beginnen wir mit einem einfachen Count-up-Chronometer , mit dem die Laufzeit eines Athleten gemessen werden kann.
OK, Auf Android Studio erstellen Sie ein neues Projekt:
  • File > New > New Project > Empty Activity
    • Name: ChronometerExample
    • Package name: org.o7planning.chronometerexample
    • Language: Java
Die Interface des Beispiel:
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=".MainActivity">


    <TextView
        android:id="@+id/textView_info"
        android:layout_width="378dp"
        android:layout_height="24dp"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:gravity="center_horizontal"
        android:text="(Info)"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Chronometer
        android:id="@+id/chronometerExample"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_weight="1"
        android:gravity="center_horizontal"
        android:textSize="60sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView_info" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:orientation="horizontal"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/chronometerExample">

        <Button
            android:id="@+id/button_start"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="fill_vertical"
            android:layout_weight="1"
            android:text="Start"
            android:textAllCaps="false" />

        <Button
            android:id="@+id/button_stop"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="fill_vertical"
            android:layout_weight="1"
            android:text="Stop"
            android:textAllCaps="false" />

        <Button
            android:id="@+id/button_resetBaseTime"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="fill_vertical"
            android:layout_weight="1"
            android:text="Reset"
            android:textAllCaps="false" />

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package com.example.chronometerexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.SystemClock;
import android.view.View;
import android.widget.Button;
import android.widget.Chronometer;
import android.widget.TextView;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private TextView textViewInfo;
    private Chronometer chronometer;
    private Button buttonStart;
    private Button buttonStop;
    private Button buttonResetBaseTime;

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

        this.textViewInfo = (TextView) findViewById(R.id.textView_info);
        this.chronometer = (Chronometer)findViewById(R.id.chronometerExample);

        this.buttonStart = (Button)findViewById(R.id.button_start);
        this.buttonStop = (Button)findViewById(R.id.button_stop);
        this.buttonResetBaseTime = (Button)findViewById(R.id.button_resetBaseTime);

        this.buttonStop.setEnabled(false);
        this.buttonResetBaseTime.setEnabled(false);

        this.buttonStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                doStart();
            }
        });

        this.buttonStop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                doStop();
            }
        });


        this.buttonResetBaseTime.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                doResetBaseTime();
            }
        });
    }

    // @totalMilliseconds: milliseconds since system boot, including time spent in sleep.
    private void showInfo(long totalMilliseconds)  {
        // Seconds
        long totalSecs = totalMilliseconds / 1000;
        // Show Info
        long hours = totalSecs / 3600;
        long minutes = (totalSecs % 3600) / 60;
        long seconds = totalSecs % 60;

        this.textViewInfo.setText("Base Time: " + totalSecs +" ~ " + hours + " hours " + minutes+" minutes " + seconds + " seconds");
    }

    private void doStart()  {
        // Returns milliseconds since system boot, including time spent in sleep.
        long elapsedRealtime = SystemClock.elapsedRealtime();
        // Set the time that the count-up timer is in reference to.
        this.chronometer.setBase(elapsedRealtime);
        this.chronometer.start();
        this.showInfo(elapsedRealtime);
        //
        this.buttonStart.setEnabled(false);
        this.buttonStop.setEnabled(true);
        this.buttonResetBaseTime.setEnabled(true);
    }

    private void doStop()  {
        this.chronometer.stop();
        //
        this.buttonStart.setEnabled(true);
        this.buttonStop.setEnabled(false);
        this.buttonResetBaseTime.setEnabled(false);
    }

    private void doResetBaseTime()  {
        // Returns milliseconds since system boot, including time spent in sleep.
        long elapsedRealtime = SystemClock.elapsedRealtime();
        // Set the time that the count-up timer is in reference to.
        this.chronometer.setBase(elapsedRealtime);
        this.showInfo(elapsedRealtime);
    }

}

5. Example: Chronometer (Count down)

Das Beispiel über einen Count-Down Chronometer.
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=".MainActivity">


    <TextView
        android:id="@+id/textView_1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginRight="16dp"
        android:background="#D7F3C9"
        android:gravity="center_horizontal"
        android:text="Count Down Chronometer"
        app:layout_constraintHorizontal_bias="0.047"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Chronometer
        android:id="@+id/chronometerCountDown"
        android:countDown="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_weight="1"
        android:gravity="center_horizontal"
        android:textSize="60sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView_1" />

    <Button
        android:id="@+id/button_start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="Start"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/chronometerCountDown" />


</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package com.example.chronometerexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Chronometer;

public class MainActivity extends AppCompatActivity {

    private Button buttonStart;
    private Chronometer chronometerCountDown;

    private int counter = 10;

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

        this.chronometerCountDown = (Chronometer) findViewById(R.id.chronometerCountDown);
        this.buttonStart = (Button) findViewById(R.id.button_start);

        this.chronometerCountDown.setText(counter + "");

        this.buttonStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                doStart();
            }
        });

        // This listener will customize the chronometer text content.
        // It will show number from 10 to 0 repeatedly.
        this.chronometerCountDown.setOnChronometerTickListener(new Chronometer.OnChronometerTickListener() {
            @Override
            public void onChronometerTick(Chronometer chronometer) {
                onChronometerTickHandler();
            }
        });
    }


    private void onChronometerTickHandler()  {
        if(this.counter < 0) {
            this.counter = 10;
        }
        this.chronometerCountDown.setText(counter + "");
        this.counter--;
    }


    private void doStart()  {
        this.chronometerCountDown.start();
    }

}

6. Example: Custom Format

Das folgende Beispiel erlaubt Sie, die Textanzeige in Chronometer anzupassen:
main_activity.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=".MainActivity">


    <TextView
        android:id="@+id/textView_2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginRight="16dp"
        android:background="#D7F3C9"
        android:gravity="center_horizontal"
        android:text="Custom Format"
        app:layout_constraintHorizontal_bias="0.047"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Chronometer
        android:id="@+id/chronometer_customFormat"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_weight="1"
        android:gravity="center_horizontal"
        android:textSize="30sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView_2" />

    <Button
        android:id="@+id/button_start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="Start"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/chronometer_customFormat" />


</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package com.example.chronometerexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.SystemClock;
import android.view.View;
import android.widget.Button;
import android.widget.Chronometer;

public class MainActivity extends AppCompatActivity {

    private Button buttonStart;
    private Chronometer chronometerCustomFormat;

    private int counter = 10;

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

        this.chronometerCustomFormat = (Chronometer) findViewById(R.id.chronometer_customFormat);
        this.chronometerCustomFormat.setText("Please click start!");
        this.buttonStart = (Button) findViewById(R.id.button_start);


        this.buttonStart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                doStart();
            }
        });


        this.chronometerCustomFormat.setOnChronometerTickListener(new Chronometer.OnChronometerTickListener() {
            @Override
            public void onChronometerTick(Chronometer chronometer) {
                onChronometerTickHandler();
            }
        });
    }


    private void onChronometerTickHandler()  {
        long delta = SystemClock.elapsedRealtime() - this.chronometerCustomFormat.getBase();

        int h = (int) ((delta / 1000) / 3600);
        int m = (int) (((delta / 1000) / 60) % 60);
        int s = (int) ((delta / 1000) % 60);

        String customText = h +" hours " + m +" minutes " + s +" seconds";

        this.chronometerCustomFormat.setText(customText);
    }


    private void doStart()  {
        long base = SystemClock.elapsedRealtime();
        this.chronometerCustomFormat.setBase(base);
        this.chronometerCustomFormat.start();
    }

}

Anleitungen Android

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