如何在Android中反转TextView跑马灯的方向？

此示例演示了如何反转TextView的跑马灯方向。

步骤1 - 在Android Studio中创建一个新项目，转到文件⇒新建项目，并填写所有必需的详细信息以创建新项目。

步骤2 - 将以下代码添加到res/layout/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:gravity = "center"
   android:layout_height = "match_parent">
   <TextView
      android:id = "@+id/text"
      android:textSize = "20dp"
      android:textAlignment = "center"
      android:layout_width = "match_parent"
      android:ellipsize = "marquee"
      android:layoutDirection = "rtl"
      android:textDirection = "rtl"
      android:fadingEdge = "horizontal"
      android:marqueeRepeatLimit = "marquee_forever"
      android:scrollHorizontally = "true"
      android:textColor = "#ff4500"
      android:text = "كيفية عكس اتجاه سرادق.....كيفية عكس اتجاه سرادق......."
      android:layout_height = "wrap_content"
      android:singleLine = "true" />
</RelativeLayout>

在上面的代码中，我们使用了TextView和ellipsize属性作为跑马灯，如下所示 -

android:ellipsize = "marquee"
android:layoutDirection = "rtl"
android:textDirection = "rtl"
android:fadingEdge = "horizontal"
android:marqueeRepeatLimit = "marquee_forever"
android:scrollHorizontally = "true"
android:singleLine = "true"

步骤3 - 将以下代码添加到src/MainActivity.java

package com.example.andy.myapplication;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      TextView txt = findViewById(R.id.text);
      txt.setSelected(true);
   }
}