文字切换(TextSwitcher)使用

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目录

TextSwitcher

TextSwitcher 继承自ViewSwitcher, ViewSwitcher继承自ViewAnimator.

使用其实现文字的切换.

使用方式:

    <TextSwitcher
        android:id="@+id/textSwitcher"
        android:layout_width="400dp"
        android:layout_height="400dp">
    </TextSwitcher>

使用实例

activity_main.xml文件:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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">

    <TextSwitcher
        android:id="@+id/textSwitcher"
        android:layout_width="400dp"
        android:layout_height="400dp">
    </TextSwitcher>

</android.support.constraint.ConstraintLayout>

代码:

package com.example.user.viewsw;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.LinearLayout;
import android.widget.TextSwitcher;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ViewSwitcher;

public class MainActivity extends Activity implements ViewSwitcher.ViewFactory, View.OnTouchListener {
    /**
     * TextSwitcher 的引用
     */
    private TextSwitcher mtestSwitcher;
    /**
     * 文字数组
     */
    final String[] strs = new String[] {
            "数学老师",
            "美食家",
            "天才",
            "儿童"
    };

    /**
     * 当前选中的文字id序号
     */
    private int currentPosition;
    /**
     * 按下点的X坐标
     */
    private float downX;


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

        //TextSwitcher
        mtestSwitcher  = (TextSwitcher) findViewById(R.id.textSwitcher);
        //设置Factory
        mtestSwitcher.setFactory(this);
        //设置OnTouchListener，我们通过Touch事件来切换图片
        mtestSwitcher.setOnTouchListener(this);

        //初始位置为0
        currentPosition = 0;
        //设置动画
        mtestSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        mtestSwitcher.setOutAnimation( AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));

    }

    @Override
    public View makeView() {
        final TextView textView = new TextView(this);
        textView.setTextSize(100);
        textView.setLayoutParams(new TextSwitcher.LayoutParams(
                LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.FILL_PARENT));
        textView.setTextColor(Color.rgb(255, 0, 0));
        textView.setText(strs[currentPosition]);
        return textView;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:{
                //手指按下的X坐标
                downX = event.getX();
                break;
            }
            case MotionEvent.ACTION_UP:{
                float lastX = event.getX();
                //抬起的时候的X坐标大于按下的时候移动
                if(lastX > downX){
                    if(currentPosition > 0){
                        currentPosition --;
                        mtestSwitcher.setCurrentText(strs[currentPosition]);
                    }else{
                        Toast.makeText(this, "已经是第一", Toast.LENGTH_SHORT).show();
                    }
                }

                if(lastX < downX){
                    if(currentPosition < strs.length - 1){
                        currentPosition ++ ;
                        mtestSwitcher.setCurrentText(strs[currentPosition]);

                    }else{
                        Toast.makeText(this, "到了最后", Toast.LENGTH_SHORT).show();
                    }
                }
            }

            break;
        }

        return true;
    }

}

运行结果:

image.png
image.png

参考

Android_TextSwitcher和ImageSwitcher