在Android中隨機更改背景圖像

Question

我在測驗應用程序中有一個活動，我想每5秒更改其背景。我如何隨機化我的可繪製文件夾中的圖像，並將它們作爲我活動的背景圖像。注意：這只是一項活動。

任何幫助將不勝感激。謝謝。

Answer 1

使用Handler或Timertask爲每5秒改變活動背景：

public static int count=0; 
int[] drawablearray=new int[]{R.drawable.One,R.drawable.Two,..}; 
new Handler().postDelayed(new Runnable() { 
    public void run() { 

     if(count<drawablearray.length){ 

      Your_Current_Activity.this.getWindow(). 
       setBackgroundDrawableResource(drawablearray[count]); 

      count++; //<<< increment counter here 
     } 
     else{ 
      // reset counter here 
      count=0; 
     } 

     } 
    }, 5000); 

Answer 2

您可以創建可繪製的數組是這樣的：

<array name="myImages"> 
     <item>@drawable/img1</item> 
     <item>@drawable/img2</item> 
     <item>@drawable/img3</item> 
</array> 

你可以讓他們像這樣：

Resources res = getResources(); 
TypedArray myImages = res.obtainTypedArray(R.array.myImages); 

現在創建隨機數字：

Random r = new Random(myImages.length()) 
int i = r.nextInt(); 

Drawable drawable = icons.getDrawable(i); 

現在每隔5秒將它們設置爲背景（如ρяσѕρєяs示例中所示）。

Answer 3

public class Test extends Activity{ 
    //instantiate a handler object 
private Handler imageHandler = new Handler(); 
    //array containing drawables ids 
int[] myarray = new int[]{R.drawable.image1,.....}; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    //add a runnable to the message queue 
    imageHandler.post(handle); 
} 

private final Runnable handle = new Runnable(){ 
    public void run(){ 
     try { 
      Random r = new Random(); 
      int i = r.nextInt(myarray.length); 
      Test.this.getWindow().setBackgroundDrawableResource(myarray[i]); 
      imageHandler.postDelayed(this, 5000);  
     } 
     catch (Exception e) { 
      Log.d("Test", e.toString()); 
     } 
    } 
}; 

}