扩展未调用的类动画后

Question

我有两个类，其中一个包含我想要应用的动画。 但由于未知的原因，它不起作用。

我的主要课程：

package com.example.tachles;
import android.os.Bundle;
import android.text.Html;
import android.text.Spanned;
import android.view.Menu;
import android.view.MenuItem;
public class History_01_01 extends TextSet {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        String formattedText = getString(R.string.zionut01);
        Spanned result = Html.fromHtml(formattedText);
        text.setText(result);
    }
    public void sizeUp(MenuItem item) {

        super.sizeUp(item);
    }
    public void sizeDown(MenuItem item) {

        super.sizeDown(item);

    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
                getMenuInflater().inflate(R.menu.textbar, menu);
                return true;
    }

    @Override
    protected void onStart() {
        super.onStart();

    }
    @Override
    protected void onStop() {
        super.onStop();

    }
}

我要扩展的课程

package com.example.tachles;

import android.app.ActionBar;
import android.app.Activity;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.util.TypedValue;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

public class TextSet extends Activity {
    TextView text;
    float size;
    ActionBar actionBar;
    private final String TEXT_SIZE = "textsize";
    final String MyPref = "preference";
    SharedPreferences settings;
    Editor editor;
    int onStartCount = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.textpage);
        text = (TextView) findViewById(R.id.textView1);

        settings = this.getSharedPreferences(MyPref, 0);
        text.setTextSize(settings.getFloat(TEXT_SIZE, 15));
        editor = settings.edit();

        onStartCount = 1;
        if (savedInstanceState == null) {
            this.overridePendingTransition(R.anim.anim_slide_in_left,
                    R.anim.anim_slide_out_left);
        } else {
            onStartCount = 2;
        }


    }

    public void sizeUp(MenuItem item) {
        size = text.getTextSize();
        if (size < 80) {
            text.setTextSize(TypedValue.COMPLEX_UNIT_PX, (float) (size + 7));
        }

    }

    public void sizeDown(MenuItem item) {
        size = text.getTextSize();
        if (size > 25) {
            text.setTextSize(TypedValue.COMPLEX_UNIT_PX, (float) (size - 7));
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.textbar, menu);
        return true;
    }

    @Override
    protected void onStart() {

        super.onStart();

        if (onStartCount > 1) {
            this.overridePendingTransition(R.anim.anim_slide_in_right,
                    R.anim.anim_slide_out_right);

        } else if (onStartCount == 1) {
            onStartCount++;
        }


    }


    @Override
    protected void onStop() {
        super.onStop();


        SharedPreferences.Editor editor = settings.edit();
        editor.putFloat(TEXT_SIZE, text.getTextSize()
                / getResources().getDisplayMetrics().scaledDensity);
        editor.commit();
    }



}

没有错误，它运行正常，但没有动画...... 我在另一个类上使用相同的动画，xml没有问题。