Backgrand image java

Question

我想添加一個圖像到android studio的背景，但我不知道如何去做。在下面的代碼中，我有公共靜態最終顏色BACKGROUND_COLOR = Color.WHITE ;,但我想改變它是背景是一個圖像不是顏色。我該怎麼做呢？由於

package com.udacity.gamedev.icicles; 

import com.badlogic.gdx.graphics.Color; 
import com.badlogic.gdx.math.Vector2; 


public class Constants { 
    public static final float WORLD_SIZE = 10.0f; 
    public static final Color BACKGROUND_COLOR = Color.WHITE; 


    public static final float PLAYER_HEAD_RADIUS = 0.5f; 
    public static final float PLAYER_HEAD_HEIGHT = 4.0f * PLAYER_HEAD_RADIUS; 
    public static final float PLAYER_LIMB_WIDTH = 0.1f; 
    public static final int PLAYER_HEAD_SEGMENTS = 20; 
    public static final Color PLAYER_COLOR = Color.BLACK; 
    public static final float PLAYER_MOVEMENT_SPEED = 10.0f; 

    public static final float ACCELEROMETER_SENSITIVITY = 0.5f; 
    public static final float GRAVITATIONAL_ACCELERATION = 9.8f; 

    public static final float ICICLES_HEIGHT = 1.0f; 
    public static final float ICICLES_WIDTH = 0.5f; 
    public static final Vector2 ICICLES_ACCELERATION = new Vector2(0, -5.0f); 
    public static final Color ICICLE_COLOR = Color.WHITE; 

    public static final float HUD_FONT_REFERENCE_SCREEN_SIZE = 480.0f; 
    public static final float HUD_MARGIN = 20.0f; 

    public static final String ASY_LABEL = "Hillary"; 
    public static final String EDIUM_LABEL = "Sanders"; 
    public static final String ARD_LABEL = "Next"; 
    public static final String ONE_LABEL = "Carson"; 
    public static final String EASY_LABEL = "Ted"; 
    public static final String MEDIUM_LABEL = "Rubio"; 
    public static final String HARD_LABEL = "Trump"; 
    public static final String SAM_LABEL = "Next"; 

    public static final float ASY_SPAWNS_PER_SECOND = 10; 
    public static final float EDIUM_SPAWNS_PER_SECOND = 15; 
    public static final float ARD_SPAWNS_PER_SECOND = 20; 
    public static final float ONE_SPAWNS_PER_SECOND = 5; 
    public static final float EASY_SPAWNS_PER_SECOND = 10; 
    public static final float MEDIUM_SPAWNS_PER_SECOND = 15; 
    public static final float HARD_SPAWNS_PER_SECOND = 20; 
    public static final float SAM_SPAWNS_PER_SECOND = 25; 

    // TODO: Add constants for the color of each difficulty select circle 
    public static final Color ASY_COLOR = new Color(0xff0000ff); 
    public static final Color EDIUM_COLOR = new Color(0xff0000ff); 
    public static final Color ARD_COLOR = new Color(0, 0, 0, 1); 
    public static final Color ONE_COLOR = new Color(0, 0, 1, 1); 
    public static final Color EASY_COLOR = new Color(0, 0, 1, 1); 
    public static final Color MEDIUM_COLOR = new Color(0, 0, 1, 1); 
    public static final Color HARD_COLOR = new Color(0, 0, 1, 1); 
    public static final Color SAM_COLOR = new Color(0, 0, 0, 1); 

    // TODO: Add constant for the size of the difficulty world 
    public static final float DIFFICULTY_WORLD_SIZE = 780.0f; 

    // TODO: Add constant for the radius of the difficulty select "buttons" 
    public static final float DIFFICULTY_BUBBLE_RADIUS = DIFFICULTY_WORLD_SIZE/12; 

    // TODO: Add constant for the scale of the difficulty labels (1.5 works well) 
    public static final float DIFFICULTY_LABEL_SCALE = 1.5f; 

    // TODO: Add Vector2 constants for the centers of the difficulty select buttons 
    public static final Vector2 ASY_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE/2, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 EDIUM_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE/3, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 ARD_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE/6, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 ONE_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE* 2/3, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 EASY_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE/2, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 MEDIUM_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE/3, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 HARD_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE * 2/3, DIFFICULTY_WORLD_SIZE/2); 
    public static final Vector2 SAM_CENTER = new Vector2(DIFFICULTY_WORLD_SIZE/6, DIFFICULTY_WORLD_SIZE/2); 


    public enum Difficulty { 
     ASY(ASY_SPAWNS_PER_SECOND, ASY_LABEL), 
     EDIUM(EDIUM_SPAWNS_PER_SECOND, EDIUM_LABEL), 
     ARD(ARD_SPAWNS_PER_SECOND, ARD_LABEL), 
     ONE(ONE_SPAWNS_PER_SECOND, ONE_LABEL), 
     EASY(EASY_SPAWNS_PER_SECOND, EASY_LABEL), 
     MEDIUM(MEDIUM_SPAWNS_PER_SECOND, MEDIUM_LABEL), 
     HARD(HARD_SPAWNS_PER_SECOND, HARD_LABEL), 
     SAM(SAM_SPAWNS_PER_SECOND, SAM_LABEL); 

     float spawnRate; 
     String label; 

     Difficulty(float spawnRate, String label) { 
      this.spawnRate = spawnRate; 
      this.label = label; 
     } 
    } 
} 

Answer 1

一般來說，如果你想用一個恆定的圖像應用到佈局的背景下，您可以將圖像複製到項目的繪製文件夾，做這樣的事情：

可繪製可繪製= ContextCompat。 getDrawable（MainActivity.this，R.drawable.storm）; screenLayout.setBackground（drawable）;

Answer 2

只需在您的XML佈局中添加以下行。

android:background="@drawable/background" 

然後，將圖像添加到可繪製文件夾中。