Question

我是android领域的新手。我正在定期在main.xml中心显示两个图像。代码运行成功，但没有显示任何图像。这是代码。

  package com.example.radio;
   import java.io.IOException;
   import java.util.Timer;
   import java.util.TimerTask;

   import android.app.Activity;
   import android.graphics.Bitmap;
   import android.graphics.BitmapFactory;
   import android.os.Bundle;
   import android.os.Handler;
   import android.os.Message;
   import android.util.Log;
   import android.widget.ImageView;

    public class Radio extends Activity 
    {
private ImageView _imagView;
private Timer _timer;
private int _index;
private MyHandler handler;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_radio);
    handler= new MyHandler();
    _imagView=(ImageView) findViewById(R.id.speak);

    _index=0;
    _timer= new Timer();
    _timer.schedule(new TickClass(), 500, 200);
}

private class TickClass extends TimerTask
{
    @Override
    public void run() {
        // TODO Auto-generated method stub
        handler.sendEmptyMessage(_index);
        _index++;
    }
}

private class MyHandler extends Handler
{
    @Override
    public void handleMessage(Message msg) {
        // TODO Auto-generated method stub
        super.handleMessage(msg);

        try {
                Bitmap bmp= BitmapFactory.decodeStream(Radio.this.getAssets().open("drum_"+_index+".png"));
                _imagView.setImageBitmap(bmp);

                Log.v("Loaing Image: ",_index+"");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            Log.v("Exception in Handler ",e.getMessage());
        }
    }}}

Answer 1

我在这里发布了一个示例代码。您可以像这样使用＆gt;＆gt;

public void onCreate() {

    ImageView backgroundImageView = findViewById(R.id.background);
    backgroundImageView.postDelayed(new Runnable() {
        static int i = 0;
        public void run() {
            ImageView.this.setImageResource(
                i++ % 2 == 0 ?
                    R.drawable.background_image1 :
                    R.drawable.background_image2);
            ImageView.this.postDelayed(this, 1000);
        }
    }, 1000);
}

Answer 2

您可以在应用程序中使用以下示例代码并替换drawables ...它可以满足您的要求......

int cargallery[] = { R.drawable.ford_suv_black,
            R.drawable.lincoln_town_car_black };
    int carIndex = -1;
    public static final int UPDATE_IMAGE = 1000;
    ImageView carimage = null;

private Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            if (msg.what == UPDATE_IMAGE) {
                if (carIndex >= cargallery.length - 1) {
                    carIndex = -1;
                }
                carIndex++;

                carimage.setImageResource(cargallery[carIndex]);
                reloadCarImage();
            }
        };
    };

    private void reloadCarImage() {

        Message msg = new Message();
        msg.what = UPDATE_IMAGE;
        mHandler.sendMessageDelayed(msg, 1000);
    }

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.homescreen);
        carimage = (ImageView) findViewById(R.id.carview);
        reloadCarImage();
}

Answer 3

int []imageArray={R.drawable.imgone,R.drawable.imgtwo,R.drawable.imgthree};

final Handler handler = new Handler();
         Runnable runnable = new Runnable() {
            int i=0;
            public void run() {
                imageView.setImageResource(imageArray[i]);
                i++;
                if(i>imageArray.length-1)
                {
                i=0;    
                }
                handler.postDelayed(this, 100);  //for interval... 
            }
        };
        handler.postDelayed(runnable, 2000); //for initial delay..
    }

如何定期显示图像

3 个答案: