Android 应用程序可在模拟器上运行但不能在真实设备上运行

Question

刚刚编写了这个用于测试的简单应用:一个按钮显示日期和时间，另一个按钮选择并显示随机颜色。它在 Emulator 上运行良好，但当我尝试在真实设备上运行该应用程序时，按钮什么都不做(不起作用)。

谁能帮我理解为什么？

主要 Activity .java:

package yuvallevy.allyouneedapp;

import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.util.Date;
import java.util.Random;

public class MainActivity extends AppCompatActivity {

    private Button btnShowTime;
    private Button btnRandomColor;
    private TextView timeText;
    private TextView randomColorView;

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

        btnRandomColor = (Button) findViewById(R.id.btnRandomColor);
        btnShowTime = (Button) findViewById(R.id.btnShowTime);
        timeText = (TextView) findViewById(R.id.timeText);
        randomColorView = (TextView) findViewById(R.id.randomColorView);

        btnShowTime.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String currentDataTimeString = java.text.DateFormat.getDateTimeInstance().format(new Date());
                timeText.setText(currentDataTimeString);
            }
        });

        btnRandomColor.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Random rnd = new Random();
                int color = Color.argb(255, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256));
                randomColorView.setBackgroundColor(color);
            }
        });
    }
}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <Button
        android:id="@+id/btnShowTime"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_toLeftOf="@+id/randomColorView"
        android:layout_toStartOf="@+id/randomColorView"
        android:text="Show Time"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <TextView
        android:id="@+id/timeText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/btnRandomColor"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_toEndOf="@+id/btnRandomColor"
        android:layout_toRightOf="@+id/btnRandomColor" />

    <Button
        android:id="@+id/btnRandomColor"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@id/btnShowTime"
        android:text="Random Color"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <TextView
        android:id="@+id/randomColorView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/btnRandomColor"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_alignTop="@+id/btnRandomColor"
        android:layout_toRightOf="@+id/btnRandomColor" />


</RelativeLayout>

AndoirdManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="yuvallevy.allyouneedapp" >

    <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" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

Answer 1

我怀疑这个明显的问题与属性 android:supportsRtl="true" 和您的设备/模拟器的不同 API 级别有关。

来自official doc :

android:supportsRtl

Declares whether your application is willing to support right-to-left (RTL) layouts. If set to true and targetSdkVersion is set to 17 or higher, various RTL APIs will be activated and used by the system so your app can display RTL layouts. If set to false or if targetSdkVersion is set to 16 or lower, the RTL APIs will be ignored or will have no effect and your app will behave the same regardless of the layout direction associated to the user's Locale choice (your layouts will always be left-to-right).

The default value of this attribute is false.

This attribute was added in API level 17.

这可能会导致模拟器和您的设备之间出现不同的行为。

您需要根据标志修复您的布局，或尝试删除此标志。