java代码如何为button添加xml背景？

        DirectionalLayout dl = (DirectionalLayout) findComponentById(ResourceTable.Id_id_dl); 

 
        Button btn = new Button(this); 

 
        //LayoutConfig(int width, int height, int alignment, float weight) 

        DirectionalLayout.LayoutConfig config = new DirectionalLayout.LayoutConfig( 

                600, 300 

        ); 

        config.alignment = LayoutAlignment.START; 

        btn.setLayoutConfig(config); 

 
        btn.setPadding(0, 0, 0, 0); 

        btn.setMarginLeft(20); 

        btn.setMarginTop(20); 

 
        btn.setText("点击"); 

        btn.setTextSize(60, Text.TextSizeType.VP); 

        btn.setTextAlignment(TextAlignment.CENTER); 

 
        //简单点：直接设置背景颜色 

        /* 

        ShapeElement shapeElement = new ShapeElement(); 

        shapeElement.setRgbColor(new RgbColor(255,255,0)); 

        btn.setBackground(shapeElement); 

         */ 

 
        //复杂点1 

        /* 

        // 创建正常状态下元素 

        ShapeElement normalShapeElement = new ShapeElement(); 

        normalShapeElement.setShape(ShapeElement.RECTANGLE); 

        normalShapeElement.setRgbColor(RgbColor.fromArgbInt(0xFFff0000)); 

        normalShapeElement.setCornerRadius(btn.getHeight()/2.0f); 

        normalShapeElement.setStroke(20, RgbColor.fromArgbInt(0xff0000ff)); 

 
        // 创建按下状态下元素 

        ShapeElement pressedShapeElement = new ShapeElement(); 

        pressedShapeElement.setShape(ShapeElement.RECTANGLE); 

        pressedShapeElement.setRgbColor(RgbColor.fromArgbInt(0xFF00ff00)); 

        pressedShapeElement.setCornerRadius(btn.getHeight()/2.0f); 

        pressedShapeElement.setStroke(20, RgbColor.fromArgbInt(0xff0000ff)); 

 
        StateElement stateElement = new StateElement(); 

        stateElement.addState(new int[]{ComponentState.COMPONENT_STATE_PRESSED}, pressedShapeElement); 

        stateElement.addState(new int[]{ComponentState.COMPONENT_STATE_EMPTY}, normalShapeElement); 

        btn.setBackground(stateElement); 

        */ 

 
        //复杂点2 

        // 创建正常状态下元素 

        Resource normalResource = null; 

        try { 

            normalResource = this.getResourceManager().getResource(ResourceTable.Media_p1); 

        } catch (IOException e) { 

            e.printStackTrace(); 

        } catch (NotExistException e) { 

            e.printStackTrace(); 

        } 

        PixelMapElement normalElement = new PixelMapElement(normalResource); 

 
        // 创建按下状态下元素 

        Resource pressedResource = null; 

        try { 

            pressedResource = this.getResourceManager().getResource(ResourceTable.Media_p2); 

        } catch (IOException e) { 

            e.printStackTrace(); 

        } catch (NotExistException e) { 

            e.printStackTrace(); 

        } 

        PixelMapElement pressedElement = new PixelMapElement(pressedResource); 

 
        StateElement stateElement = new StateElement(); 

        stateElement.addState(new int[]{ComponentState.COMPONENT_STATE_PRESSED}, pressedElement); 

        stateElement.addState(new int[]{ComponentState.COMPONENT_STATE_EMPTY}, normalElement); 

        btn.setBackground(stateElement); 

         

        //添加到父窗口 

        dl.addComponent(btn); 
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
131.
132.
133.
134.
135.
136.
137.
138.
139.
140.
141.
142.
143.
144.