渐显启动界面.md

package com.leigo.textswitcherdemo;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.TextView;

import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.JsonHttpResponseHandler;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.assist.FailReason;
import com.nostra13.universalimageloader.core.listener.ImageLoadingListener;
import com.nostra13.universalimageloader.core.listener.SimpleImageLoadingListener;

import org.apache.http.Header;
import org.json.JSONException;
import org.json.JSONObject;

/** * Created by Administrator on 2015/3/16. */
public class SplashActivity extends Activity {

    public Animation splashAnim;

    ImageView mImageView;
    TextView mText;

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

        mImageView = (ImageView) findViewById(R.id.splash);
        mText = (TextView) findViewById(R.id.text);

        splashAnim = AnimationUtils.loadAnimation(this, R.anim.splash);
        splashAnim.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {
            }

            @Override
            public void onAnimationEnd(Animation animation) {
                Intent intent = new Intent(SplashActivity.this, MainActivity.class);
                startActivity(intent);
                finish();
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });

        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
        if (!sp.contains("preferences_splash_text")) {
            mText.setText(R.string.splash_text);
            mImageView.setImageResource(R.drawable.splash);
            mImageView.startAnimation(splashAnim);

            AsyncHttpClient client = new AsyncHttpClient();
            client.get("http://news-at.zhihu.com/api/4/start-image/1080*1776", new JsonHttpResponseHandler() {

                @Override
                public void onStart() {
                    super.onStart();
                }

                @Override
                public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
                    super.onSuccess(statusCode, headers, response);
                    try {
                        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(SplashActivity.this);
                        SharedPreferences.Editor editor = sp.edit();
                        editor.putString("preferences_splash_text", response.getString("text"));
                        editor.putString("preferences_splash_image", response.getString("img"));
                        editor.apply();

                        ImageLoader.getInstance().loadImage(response.getString("img"), new SimpleImageLoadingListener() {
                            @Override
                            public void onLoadingStarted(String imageUri, View view) {

                            }

                            @Override
                            public void onLoadingFailed(String imageUri, View view, FailReason failReason) {

                            }

                            @Override
                            public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
                                FileUtils.storeImage(SplashActivity.this, loadedImage);
                            }

                            @Override
                            public void onLoadingCancelled(String imageUri, View view) {

                            }
                        });

                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onFailure(int statusCode, Header[] headers, String responseString, Throwable throwable) {
                    super.onFailure(statusCode, headers, responseString, throwable);
                }


                @Override
                public void onRetry(int retryNo) {
                    super.onRetry(retryNo);
                }
            });
        } else {
            String text = sp.getString("preferences_splash_text", getString(R.string.splash_text));
            mText.setText(text);
            Bitmap bitmap = BitmapFactory.decodeFile(FileUtils.getOutputMediaFile(this).getAbsolutePath());
            mImageView.setImageBitmap(bitmap);
            mImageView.startAnimation(splashAnim);
        }
    }
}

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

    <ImageView  android:id="@+id/splash" android:layout_width="match_parent" android:layout_height="match_parent" android:scaleType="centerCrop" />

    <ImageView  android:layout_width="match_parent" android:layout_height="200.0dip" android:src="@drawable/mask" android:layout_alignParentBottom="true" />

    <ImageView  android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="50.0dip" android:src="@drawable/splash_logo" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" />

    <TextView  android:textSize="@dimen/text_size_12" android:textColor="#ffffffff" android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10.0dip" android:text="@string/splash_text" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:alpha="0.5" />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<set  android:shareInterpolator="false" android:zAdjustment="top" android:fillBefore="true" android:fillAfter="true" android:fillEnabled="true" xmlns:android="http://schemas.android.com/apk/res/android">
    <scale  android:duration="2500" android:pivotX="50.0%p" android:pivotY="50.0%p" android:fromXScale="1.0" android:toXScale="1.1" android:fromYScale="1.0" android:toYScale="1.1" />
    <alpha  android:duration="500" android:startOffset="2000" android:fromAlpha="1.0" android:toAlpha="0.0" />
</set>

package com.leigo.textswitcherdemo;

import android.content.Context;
import android.graphics.Bitmap;
import android.os.Environment;
import android.util.Log;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/** * Created by Administrator on 2015/3/19. */
public class FileUtils {

    private static final String TAG = FileUtils.class.getSimpleName();

    public static void storeImage(Context context, Bitmap image) {
        File pictureFile = getOutputMediaFile(context);
        if (pictureFile == null) {
            Log.d(TAG,
                    "Error creating media file, check storage permissions: ");// e.getMessage());
            return;
        }
        try {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            image.compress(Bitmap.CompressFormat.JPEG, 100, fos);
            fos.flush();
            fos.close();
        } catch (FileNotFoundException e) {
            Log.d(TAG, "File not found: " + e.getMessage());
        } catch (IOException e) {
            Log.d(TAG, "Error accessing file: " + e.getMessage());
        }
    }

    /** * Create a File for saving an image or video */
    public static File getOutputMediaFile(Context context) {
        // To be safe, you should check that the SDCard is mounted
        // using Environment.getExternalStorageState() before doing this.
        File mediaStorageDir = new File(Environment.getExternalStorageDirectory() + "/Android/data/" + context.getApplicationInfo().packageName + "/files/" + "splash");

        // This location works best if you want the created images to be shared
        // between applications and persist after your app has been uninstalled.

        // Create the storage directory if it does not exist
        if (!mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                return null;
            }
        }
        // Create a media file name
        File mediaFile = new File(mediaStorageDir.getPath() + File.separator + "splash.jpg");
        return mediaFile;
    }
}