Android 组合控件实现布局的复用的方法

所属分类：软件编程 / Android 阅读数： 50

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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>