Android 按钮实现Spinner效果

[{"title":"（ 36 个子文件 78KB ） Android 按钮实现Spinner效果","children":[{"title":"Button","children":[{"title":".project <span style='color:#111;'> 842B </span>","children":null,"spread":false},{"title":"default.properties <span style='color:#111;'> 449B </span>","children":null,"spread":false},{"title":"bin","children":[{"title":"com","children":[{"title":"zhou","children":[{"title":"activity","children":[{"title":"R$string.class <span style='color:#111;'> 424B </span>","children":null,"spread":false},{"title":"R$layout.class <span style='color:#111;'> 427B </span>","children":null,"spread":false},{"title":"MainActivity.class <span style='color:#111;'> 1.62KB </span>","children":null,"spread":false},{"title":"R$drawable.class <span style='color:#111;'> 563B </span>","children":null,"spread":false},{"title":"R.class <span style='color:#111;'> 524B </span>","children":null,"spread":false},{"title":"R$attr.class <span style='color:#111;'> 337B </span>","children":null,"spread":false},{"title":"MainActivity$1.class <span style='color:#111;'> 1.58KB </span>","children":null,"spread":false},{"title":"MainActivity$1$1.class <span style='color:#111;'> 1.54KB </span>","children":null,"spread":false},{"title":"R$id.class <span style='color:#111;'> 480B </span>","children":null,"spread":false}],"spread":true}],"spread":true}],"spread":true},{"title":"Button.apk <span style='color:#111;'> 35.78KB </span>","children":null,"spread":false},{"title":"resources.ap_ <span style='color:#111;'> 31.07KB </span>","children":null,"spread":false},{"title":"classes.dex <span style='color:#111;'> 4.79KB </span>","children":null,"spread":false}],"spread":true},{"title":"AndroidManifest.xml <span style='color:#111;'> 684B </span>","children":null,"spread":false},{"title":"src","children":[{"title":"com","children":[{"title":"zhou","children":[{"title":"activity","children":[{"title":"MainActivity.java <span style='color:#111;'> 2.03KB </span>","children":null,"spread":false}],"spread":true}],"spread":true}],"spread":true}],"spread":true},{"title":"res","children":[{"title":"values","children":[{"title":"strings.xml <span style='color:#111;'> 182B </span>","children":null,"spread":false}],"spread":true},{"title":"layout","children":[{"title":"main.xml <span style='color:#111;'> 1.88KB </span>","children":null,"spread":false},{"title":"spinner_item.xml <span style='color:#111;'> 249B </span>","children":null,"spread":false}],"spread":true},{"title":"drawable-ldpi","children":[{"title":"btn_dropdown.xml <span style='color:#111;'> 503B </span>","children":null,"spread":false},{"title":"btn_dropdown_selected.9.png <span style='color:#111;'> 2.49KB </span>","children":null,"spread":false},{"title":"btn_dropdown_normal.9.png <span style='color:#111;'> 1.79KB </span>","children":null,"spread":false},{"title":"btn_dropdown_press.9.png <span style='color:#111;'> 2.54KB </span>","children":null,"spread":false},{"title":"icon.png <span style='color:#111;'> 1.68KB </span>","children":null,"spread":false}],"spread":true},{"title":"drawable-hdpi","children":[{"title":"btn_dropdown.xml <span style='color:#111;'> 503B </span>","children":null,"spread":false},{"title":"btn_dropdown_selected.9.png <span style='color:#111;'> 2.49KB </span>","children":null,"spread":false},{"title":"btn_dropdown_normal.9.png <span style='color:#111;'> 1.79KB </span>","children":null,"spread":false},{"title":"btn_dropdown_press.9.png <span style='color:#111;'> 2.54KB </span>","children":null,"spread":false},{"title":"icon.png <span style='color:#111;'> 4.05KB </span>","children":null,"spread":false}],"spread":true},{"title":"drawable-mdpi","children":[{"title":"btn_dropdown.xml <span style='color:#111;'> 504B </span>","children":null,"spread":false},{"title":"btn_dropdown_selected.9.png <span style='color:#111;'> 2.49KB </span>","children":null,"spread":false},{"title":"btn_dropdown_normal.9.png <span style='color:#111;'> 1.79KB </span>","children":null,"spread":false},{"title":"btn_dropdown_press.9.png <span style='color:#111;'> 2.54KB </span>","children":null,"spread":false},{"title":"icon.png <span style='color:#111;'> 2.51KB </span>","children":null,"spread":false}],"spread":true}],"spread":true},{"title":".classpath <span style='color:#111;'> 280B </span>","children":null,"spread":false},{"title":"gen","children":[{"title":"com","children":[{"title":"zhou","children":[{"title":"activity","children":[{"title":"R.java <span style='color:#111;'> 1.18KB </span>","children":null,"spread":false}],"spread":true}],"spread":true}],"spread":true}],"spread":true},{"title":"assets","children":null,"spread":false}],"spread":true}],"spread":true}]