按ID搜索佈局

Question

我在獲取佈局ID時遇到問題。

splash.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="@drawable/splash_img1" > 

</LinearLayout> 

java文件

@Override 
protected void onCreate(Bundle savedStateInstance) { 
    super.onCreate(savedStateInstance); 
    setContentView(R.layout.splash); 

    int imgId[] = new int[] { R.drawable.splash_img1, R.drawable.splash_img2 }; 
    Random random = new Random(); 
    int result = random.nextInt(imgId.length); 
    LinearLayout layout = (LinearLayout) findViewById(R.layout.splash); 
    layout.setBackgroundDrawable(getResources().getDrawable(imgId[result])); 

} 

每當我跑，我得到一個搖籃打造的 「未定義佈局」 的錯誤。

Answer 1

您可以通過R.id.layout_id獲取layout。

增加號碼至您的layout文件

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/splash_layout" // <-- this to your code. 
    android:orientation="vertical" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="@drawable/splash_img1" > 

</LinearLayout> 

添加到您的.java文件

@Override 
protected void onCreate(Bundle savedStateInstance) { 
    super.onCreate(savedStateInstance); 
    setContentView(R.layout.splash); 

    int imgId[] = new int[] { R.drawable.splash_img1, R.drawable.splash_img2 }; 
    Random random = new Random(); 
    int result = random.nextInt(imgId.length); 

    // edit this part. 
    LinearLayout layout = (LinearLayout) findViewById(R.id.splash_layout); 
    layout.setBackgroundDrawable(getResources().getDrawable(imgId[result])); 

希望這有助於:)