• 執行jar包命令:
  java -jar jar路徑
• StringBuffer和StringBuilder的區別
  StringBuffer是線程同步的,而StringBuilder不是.所以StringBuilder執行速度更快.如果是在多線程中使用的話.就推薦使用StringBuffer.StackoverFlow
• 動態添加View,控制View的Margin方法

LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
    LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(30, 20, 30, 0);//這行代碼生效,這里要根據dp設置px,不然會有屏幕適配的問題

Button okButton=new Button(this);
okButton.setText("some text"); 
ll.addView(okButton, layoutParams);

• adb 打印出設置的長和寬
  兩種方法:

adb shell dumpsys window | grep cur= |tr -s " " | cut -d " " -f 4|cut -d "=" -f 2

adb shell wm density
adb shell hm density

• 控制Button圓角

新建orange_corner_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="@color/orange"/>
    <corners android:radius="4dp"/>
</shape>

給button設置背景

android:background="@drawable/orange_corner_bg"

• 監聽CoordinatorLayout的滑動

 if (appBarLayout != null) {
            CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
            AppBarLayout.Behavior behavior = (AppBarLayout.Behavior) params.getBehavior();
            if (behavior != null) {
                behavior.setDragCallback(new AppBarLayout.Behavior.DragCallback() {
                    @Override
                    public boolean canDrag(@NonNull AppBarLayout appBarLayout) {
                        return behaviorDrag;
                    }
                });
            }
        }

• CoordinatorLayout縮放

CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
            AppBarLayout.Behavior behavior = (AppBarLayout.Behavior) params.getBehavior();
            if (behavior != null) {
                behavior.onNestedFling(coordinatorLayout, appBarLayout, null, 0, -params.height, true);
            }