XML layout skills

PostInvalidate (); interface refresh
 

A list element may be 48px by default.
Android: visibility = "invisible"> set the component to show visible, not to show invisible, and disappear gone.
Android: background = "@ null" sets no background for components
Android: layout_gravity = "right | center_vertical" right and vertical center
<Button

Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: drawableTop = "@ drawable/star": Set the image above the button
Android: text = "button 1"
/>

 
<Include
Android: id = "@ + id/vip_include_top"
Android: layout_width = "fill_parent"
Android: layout_height = "wrap_content"
Android: layout_alignParentTop = "true"
Layout = "@ layout/top_1"/> contains
<SlidingDrawer
Android: id = "@ + id/sliding"
Android: layout_width = "match_parent"
Android: layout_height = "match_parent"
Android: content = "@ + id/allApps"
Android: handle = "@ + id/imageViewIcon"
Ndroid: orientation = "vertical"
> Content (Class-level control) handle must be set for drawer design)
Android: layout_alignParentBottom = "true" is always at the bottom of the parent Element
Android: scrollbars = "none" Do not scroll bars
Android: gravity: For the view control, it is used to set the position where the view text should be displayed. The default value is left.

Android: layout_gravity: relative to the parent element containing the modified element, set the location of the element in the parent element.
<Button android: layout_width = "120dip"
Android: layout_height = "wrap_content"
Android: text = "switching program"
Style = "@ android: style/ButtonBar" sets the button to the style of the button bar.
Android: id = "@ + id/btn7"
Android: layout_weight = "1"/>
 

RequestWindowFeature (Window. FEATURE_NO_TITLE); set no title
Add android: theme = "@ android: style/Theme. NoTitleBar" to the application tag to remove the title bar of all Activity interfaces.
Modify AndroidManifest. xml
This. getWindow (). setFlags (WindowManager. LayoutParams. FLAG_FULLSCREEN, WindowManager. LayoutParams. FLAG_FULLSCREEN); set full screen
<Resources>
<Style name = "tab_btn">
<Item name = "android: textAppearance"> @ style/tab_item_text_style </item>
<Item name = "android: gravity"> center_horizontal </item>
<Item name = "android: background"> @ drawable/trans </item>
<Item name = "android: layout_width"> 0.0dip </item>
<Item name = "android: layout_height"> wrap_content </item>
<Item name = "android: button"> @ null </item>
<Item name = "android: layout_weight"> 1.0 </item> the Style attribute of the Custom button
</Style>
</Resources>

<Selector xmlns: android = "http://schemas.android.com/apk/res/android">
<Item android: state_enabled = "false" android: drawable = "@ drawable/input_normal"/>
<Item android: state_pressed = "true" android: drawable = "@ drawable/input_normal"/>
<Item android: state_focused = "true" android: drawable = "@ drawable/input_over"/>
</Selector> define the component to get the focus. Click to activate the component.

<? Xml version = "1.0" encoding = "UTF-8"?>
<Shape xmlns: android = "http://schemas.android.com/apk/res/android">
<Gradient
Android: startColor = "# FFFFFF"
Android: endColor = "#000000"
Android: angle = "270"/> </shape>: Set the Drawable gradient.
SetBackgroundResource (R. drawable. bg); call

// Set the Gallery style in the getView of BaseAdapter.

TypedArray typedArray = context. obtainStyledAttributes (R. styleable. Gallery );
ImageView. setBackgroundResource (typedArray. getResourceId (R. styleable. Gallery_android_galleryItemBackground, 0 ));
Return imageView;
Android: spacing = "10dp" // Gallery Interval
 
Class 1: the property value is true or false.
 

Android: layout_centerHrizontal? Horizontal Center
Android: layout_centerVertical ?? Vertical center
Android: layout_centerInparent ??? Completely centered relative to the parent Element
Android: layout_alignParentBottom: attach the lower edge of the parent Element
Android: layout_alignParentLeft ?? Attach the left edge of the parent Element
Android: layout_alignParentRight? Attach the right edge of the parent Element
Android: layout_alignParentTop ??? Attach the upper edge of the parent Element
Android: layout_alignWithParentIfMissing? If the corresponding sibling element cannot be found, the parent element will be used as a reference object.
Class 2: the property value must be the reference name of the id"
Android: layout_below ????? Below an element
Android: layout_above ????? Above an element
Android: layout_toLeftOf ?? On the left of an element
Android: layout_toRightOf? On the Right of an element
Android: layout_alignTop ?? The top edge of the element is aligned with the top edge of an element.
Android: layout_alignLeft? The left edge of the element is aligned with the left edge of an element.
Android: layout_alignBottom: the bottom edge of the current element is aligned with the bottom edge of an element.
Android: layout_alignRight? The right edge of the element is aligned with the right edge of an element.
Category 3: attribute values are specific pixel values, such as 30dip and 40px.
Android: layout_marginBottom ?????? Distance from the bottom edge of an element
Android: layout_marginLeft ???????? Distance from the left edge of an element
Android: layout_marginRight ??????? Distance from the right edge of an element
Android: layout_marginTop ????????? Distance from the edge of an element
 
Android: scaleType: android: scaleType controls how images are resized/moved to match the size of ImageView.
ImageView. ScaleType/android: the differences between scaleType values:
CENTER/center? Centered by the original size of the image. When the length/width of the image exceeds the length/width of the View, the center part of the screenshot is displayed.
CENTER_CROP/centerCrop? Scale up the image size in the center so that the image length (width) is equal to or greater than the View length (width)
CENTER_INSIDE/centerInside? The image content is displayed in the center. The image length/width is equal to or less than the View length/width by scale down or by the original size.
FIT_CENTER/fitCenter? Scale up or down an image to the width of the View in proportion and display it in the center.
FIT_END/fitEnd ?? Scale up or down an image to the width of the View, and display it in the lower part of the View.
FIT_START/fitStart? Scale up/down an image proportionally to the width of the View, and display it in the top part of the View.
FIT_XY/fitXY? Scale up or down an image proportionally to the size of the View display MATRIX/matrix, and dynamically zoom in and zoom in the image to display it.
** Note that the names of images in the Drawable folder cannot be capitalized.