Android 组合控件实现布局的复用的方法

2019-12-12 02:21:12

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看到很多项目会有实现自己的标题栏的做法，通常的界面是左边按钮或文字，加上中间的标题和右边的按钮或文字组成的。比较好的一种做法是使用include标签，复用同一个xml文件来实现布局的复用。但是这种方法是通过代码的方式来设置标题，左右按钮等其他的属性，会导致布局属性和Activity代码耦合性比较高。

因此，我们要通过自定义View，继承ViewGroup子类来实现这样的布局，降低布局文件和Activity代码耦合性。

首先，我们需要写出布局文件layout_custom_titlebar.xml。

<?xml version="1.0" encoding="utf-8"?><merge xmlns:android="http://schemas.android.com/apk/res/android"><!-- 使用merge标签减少层级 --><Button  android:id="@+id/title_bar_left"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_alignParentLeft="true"  android:layout_centerVertical="true"  android:layout_marginLeft="5dp"  android:background="@null"  android:minHeight="45dp"  android:minWidth="45dp"  android:textSize="14sp" /><TextView  android:id="@+id/title_bar_title"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_centerInParent="true"  android:singleLine="true"  android:textSize="17sp" /><Button  android:id="@+id/title_bar_right"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_alignParentRight="true"  android:layout_centerVertical="true"  android:layout_marginRight="7dp"  android:background="@null"  android:minHeight="45dp"  android:minWidth="45dp"  android:textSize="14sp" /></merge>

2.定义自定义属性

<declare-styleable name="CustomTitleBar">  <!--标题栏背景色-->  <attr name="title_background_color" format="reference|integer" />  <!--左边按钮是否可见-->  <attr name="left_button_visible" format="boolean" />  <!--右边按钮是否可见-->  <attr name="right_button_visible" format="boolean" />  <!--标题文字-->  <attr name="title_text" format="string" />  <!--标题文字颜色-->  <attr name="title_text_color" format="color" />  <!--标题文字图标-->  <attr name="title_text_drawable" format="reference|integer" />  <!--左边按钮文字-->  <attr name="left_button_text" format="string" />  <!--左边按钮文字颜色-->  <attr name="left_button_text_color" format="color" />  <!--左边按钮图标-->  <attr name="left_button_drawable" format="reference|integer" />  <!--右边按钮文字-->  <attr name="right_button_text" format="string" />  <!--右边按钮文字颜色-->  <attr name="right_button_text_color" format="color" />  <!--右边按钮图标-->  <attr name="right_button_drawable" format="reference|integer" /></declare-styleable>

3.自定义一个View继承ViewGroup子类，这里我们继承RelativeLayout。

public class CustomTitleBar extends RelativeLayout {private Button titleBarLeftBtn;private Button titleBarRightBtn;private TextView titleBarTitle;public CustomTitleBar(Context context) {  super(context);}public CustomTitleBar(Context context, AttributeSet attrs) {  super(context, attrs);  LayoutInflater.from(context).inflate(R.layout.layout_custom_titlebar,this,true);  titleBarLeftBtn = (Button) findViewById(R.id.title_bar_left);  titleBarRightBtn = (Button) findViewById(R.id.title_bar_right);  titleBarTitle = (TextView) findViewById(R.id.title_bar_title);  TypedArray typedArray=context.obtainStyledAttributes(attrs,R.styleable.CustomTitleBar);  if(typedArray!=null){    //titleBar背景色    int titleBarBackGround=typedArray.getResourceId(R.styleable.CustomTitleBar_title_background_color, Color.BLUE);    setBackgroundColor(titleBarBackGround);    //获取是否要显示左边按钮    boolean leftButtonVisible = typedArray.getBoolean(R.styleable.CustomTitleBar_left_button_visible, true);    if (leftButtonVisible) {      titleBarLeftBtn.setVisibility(View.VISIBLE);    } else {      titleBarLeftBtn.setVisibility(View.INVISIBLE);    }    //设置左边按钮的文字    String leftButtonText = typedArray.getString(R.styleable.CustomTitleBar_left_button_text);    if (!TextUtils.isEmpty(leftButtonText)) {      titleBarLeftBtn.setText(leftButtonText);      //设置左边按钮文字颜色      int leftButtonTextColor = typedArray.getColor(R.styleable.CustomTitleBar_left_button_text_color, Color.WHITE);      titleBarLeftBtn.setTextColor(leftButtonTextColor);    } else {      //设置左边图片icon 这里是二选一 要么只能是文字 要么只能是图片      int leftButtonDrawable = typedArray.getResourceId(R.styleable.CustomTitleBar_left_button_drawable, R.mipmap.titlebar_back_icon);      if (leftButtonDrawable != -1) {        titleBarLeftBtn.setBackgroundResource(leftButtonDrawable);      }    }    //先获取标题是否要显示图片icon    int titleTextDrawable = typedArray.getResourceId(R.styleable.CustomTitleBar_title_text_drawable, -1);    if (titleTextDrawable != -1) {      titleBarTitle.setBackgroundResource(titleTextDrawable);    } else {      //如果不是图片标题 则获取文字标题      String titleText = typedArray.getString(R.styleable.CustomTitleBar_title_text);      if (!TextUtils.isEmpty(titleText)) {        titleBarTitle.setText(titleText);      }      //获取标题显示颜色      int titleTextColor = typedArray.getColor(R.styleable.CustomTitleBar_title_text_color, Color.WHITE);      titleBarTitle.setTextColor(titleTextColor);    }    //获取是否要显示右边按钮    boolean rightButtonVisible = typedArray.getBoolean(R.styleable.CustomTitleBar_right_button_visible, true);    if (rightButtonVisible) {      titleBarRightBtn.setVisibility(View.VISIBLE);    } else {      titleBarRightBtn.setVisibility(View.INVISIBLE);    }    //设置右边按钮的文字    String rightButtonText = typedArray.getString(R.styleable.CustomTitleBar_right_button_text);    if (!TextUtils.isEmpty(rightButtonText)) {      titleBarRightBtn.setText(rightButtonText);      //设置右边按钮文字颜色      int rightButtonTextColor = typedArray.getColor(R.styleable.CustomTitleBar_right_button_text_color, Color.BLUE);      titleBarRightBtn.setTextColor(rightButtonTextColor);    } else {      //设置右边图片icon 这里是二选一 要么只能是文字 要么只能是图片      int rightButtonDrawable = typedArray.getResourceId(R.styleable.CustomTitleBar_right_button_drawable, -1);      if (rightButtonDrawable != -1) {        titleBarRightBtn.setBackgroundResource(rightButtonDrawable);      }    }    typedArray.recycle();  }}public void setTitleClickListener(OnClickListener onClickListener) {  if (onClickListener != null) {    titleBarLeftBtn.setOnClickListener(onClickListener);    titleBarRightBtn.setOnClickListener(onClickListener);  }}public Button getTitleBarLeftBtn() {  return titleBarLeftBtn;}public Button getTitleBarRightBtn() {  return titleBarRightBtn;}public TextView getTitleBarTitle() {  return titleBarTitle;}}

4.正确地使用它

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><com.mumubin.demoproject.view.CustomTitleBar  android:id="@+id/ctb_view"  android:layout_width="match_parent"  android:layout_height="45dp"  app:right_button_drawable="@mipmap/sure"  app:title_text="@string/app_name" /><com.mumubin.demoproject.view.CustomTitleBar  android:layout_width="match_parent"  android:layout_height="45dp"  android:layout_marginTop="4dp"  app:title_background_color="@color/colorPrimary"  app:title_text="@string/app_name"  app:title_text_color="@color/colorAccent"  app:left_button_text="左边"  app:right_button_text="右边"/><com.mumubin.demoproject.view.CustomTitleBar  android:layout_width="match_parent"  android:layout_height="45dp"  android:layout_marginTop="4dp"  app:title_text_drawable="@mipmap/ic_launcher"  app:title_background_color="@color/colorAccent"  app:left_button_text="左边"  app:right_button_text="右边"/></LinearLayout>