Android开发要点杂记

TextView

• TextView设置drawable代码方式：

TextView textView = new TextView(context);
LayoutParams layoutParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
textView.setLayoutParams(layoutParams);
Drawable drawable = ResourceUtils.getDrawable(R.drawable.ic_name);
int px14 = ConvertUtils.dp2px(14);
drawable.setBounds(0, 0, px14, px14);
textView.setCompoundDrawables(drawable, null, null, null);
int px = ConvertUtils.dp2px(10);
textView.setCompoundDrawablePadding(px);
textView.setText("我是标题");

drawable.setBounds(left, top, right, bottom)//drawable会在这里用指定的位置绘制出来 textView.setCompoundDrawables(left, top, right, bottom)//设置绘制对象的方位

Margin

• 设置View的边距（Margin）

1. 定义在xml中通过findViewById获取的控件

    LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) textview.getLayoutParams();  
    lp.leftMargin = 0;  
    textview.setLayoutParams(lp);  

2. 通过new出来的控件

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);  
layoutParams.setMargins(10,10,10,10);//4个参数按顺序分别是左上右下  
  
textview.setLayoutParams(layoutParams);  

用@IntDef代替Enum

原文地址

使用要点：

1. 定义常量；

   //布局方式
   public static final int HORIZONTAL = 0;
   public static final int HORIZONTAL_CENTER = 1;
   public static final int VERTICAL = 2;
   

2. 用@IntDef包裹常量；用@Retention定义一个策略

   @IntDef({IFormModule.HORIZONTAL, IFormModule.HORIZONTAL_CENTER, IFormModule.VERTICAL})
   @Retention(RetentionPolicy.SOURCE)
   public @interface Orientation {}
   

   需要注意定义的interface前面需要用@的标注@interface

3. 在定义的方法上使用策略

   public void setOrientation(@Orientation int orientation) {
       System.out.println("引用布局的参数：方向：" + orientation);
   }
   
   imgPickerItem.setOrientation(IFormModule.VERTICAL);