1 实现效果
2 例子代码讲解
2.1 attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="TopBar">
<attr name="title" format="string" />
<attr name="titleTextSize" format="dimension" />
<attr name="titleTextColor" format="color" />
<attr name="leftTextColor" format="color" />
<attr name="leftBackground" format="reference|color" />
<attr name="leftText" format="string" />
<attr name="rightTextColor" format="color" />
<attr name="rightBackground" format="reference|color" />
<attr name="rightText" format="string" />
</declare-styleable>
</resources>2.2 topbar.xml
<com.xys.mytopbar.Topbar xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
android:id="@+id/topBar"
android:layout_width="match_parent"
android:layout_height="40dp"
custom:leftBackground="@drawable/blue_button"
custom:leftText="Back"
custom:leftTextColor="#FFFFFF"
custom:rightBackground="@drawable/blue_button"
custom:rightText="More"
custom:rightTextColor="#FFFFFF"
custom:title="自定义标题"
custom:titleTextColor="#123412"
custom:titleTextSize="15sp">
</com.xys.mytopbar.Topbar>2.3 TopBar.java
package com.imooc.systemwidget;
public class TopBar extends RelativeLayout {
// 包含topbar上的元素：左按钮、右按钮、标题
private Button mLeftButton, mRightButton;
private TextView mTitleView;
// 布局属性，用来控制组件元素在ViewGroup中的位置
private LayoutParams mLeftParams, mTitlepParams, mRightParams;
// 左按钮的属性值，即我们在atts.xml文件中定义的属性
private int mLeftTextColor;
private Drawable mLeftBackground;
private String mLeftText;
// 右按钮的属性值
private int mRightTextColor;
private Drawable mRightBackground;
private String mRightText;
// 标题的属性值
private float mTitleTextSize;
private int mTitleTextColor;
private String mTitle;
public TopBar(Context context) {
super(context);
}
public TopBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public TopBar(Context context, AttributeSet attrs) {
super(context, attrs);
// 设置topbar的背景
setBackgroundColor(0xFFF59563);
// 1.1 通过这个方法，将你在atts.xml中定义的declare-styleable的所有属性的值存储到TypedArray中
TypedArray ta = context.obtainStyledAttributes(attrs,
R.styleable.TopBar);
// 1.2 从TypedArray中取出对应的值来为要设置的属性赋值
mLeftTextColor = ta.getColor(R.styleable.TopBar_leftTextColor, 0);
mLeftBackground = ta.getDrawable(R.styleable.TopBar_leftBackground);
mLeftText = ta.getString(R.styleable.TopBar_leftText);
mRightTextColor = ta.getColor(R.styleable.TopBar_rightTextColor, 0);
mRightBackground = ta.getDrawable(R.styleable.TopBar_rightBackground);
mRightText = ta.getString(R.styleable.TopBar_rightText);
mTitleTextSize = ta.getDimension(R.styleable.TopBar_titleTextSize, 10);
mTitleTextColor = ta.getColor(R.styleable.TopBar_titleTextColor, 0);
mTitle = ta.getString(R.styleable.TopBar_title);
// 1.3 获取完TypedArray的值后，一般要调用recyle方法来避免重新创建的时候的错误
ta.recycle();
// 2.1 获取组件元素
mLeftButton = new Button(context);
mRightButton = new Button(context);
mTitleView = new TextView(context);
// 2.2 为组件元素设置相应的布局元素
mLeftParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
mLeftParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT, TRUE);
mRightParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
mRightParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, TRUE);
mTitlepParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
mTitlepParams.addRule(RelativeLayout.CENTER_IN_PARENT, TRUE);
// 3.1 为创建的组件元素赋值，就来源于我们在引用的attr.xml文件中给对应属性的赋值
mLeftButton.setTextColor(mLeftTextColor);
mLeftButton.setBackground(mLeftBackground);
mLeftButton.setText(mLeftText);
mRightButton.setTextColor(mRightTextColor);
mRightButton.setBackground(mRightBackground);
mRightButton.setText(mRightText);
mTitleView.setText(mTitle);
mTitleView.setTextColor(mTitleTextColor);
mTitleView.setTextSize(mTitleTextSize);
mTitleView.setGravity(Gravity.CENTER);
// 4.1 将组件元素添加到ViewGroup
addView(mLeftButton, mLeftParams);
addView(mRightButton, mRightParams);
addView(mTitleView, mTitlepParams);
// 4.2 设置按钮的点击事件，不需要具体的实现，只需调用接口的方法，回调的时候，会有具体的实现
mRightButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mListener.rightClick();
}
});
mLeftButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mListener.leftClick();
}
});
}
/**
* 设置监听
*/
// 接口对象，实现回调机制，在回调方法中通过映射的接口对象调用接口中的方法
// 而不用去考虑如何实现，具体的实现由调用者去创建
public interface topbarClickListener {
// 左按钮点击事件
void leftClick();
// 右按钮点击事件
void rightClick();
}
// 映射传入的接口对象
private topbarClickListener mListener;
// 暴露一个方法给调用者来注册接口回调，通过接口来获得回调者对接口方法的实现
public void setOnTopbarClickListener(topbarClickListener mListener) {
this.mListener = mListener;
}
/**
* 设置按钮的显示与否 通过id区分按钮，flag区分是否显示
*
* @param id id
* @param flag 是否显示
*/
public void setButtonVisable(int id, boolean flag) {
if (flag) {
if (id == 0) {
mLeftButton.setVisibility(View.VISIBLE);
} else {
mRightButton.setVisibility(View.VISIBLE);
}
} else {
if (id == 0) {
mLeftButton.setVisibility(View.GONE);
} else {
mRightButton.setVisibility(View.GONE);
}
}
}
}
2.4 topbar_test.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp"
tools:context=".MainActivity">
<!-- <include layout="@layout/topbar" /> -->
<com.imooc.systemwidget.TopBar
android:id="@+id/topBar"
android:layout_width="match_parent"
android:layout_height="40dp"
custom:leftBackground="@drawable/blue_button"
custom:leftText="Back"
custom:leftTextColor="#FFFFFF"
custom:rightBackground="@drawable/blue_button"
custom:rightText="More"
custom:rightTextColor="#FFFFFF"
custom:title="自定义标题"
custom:titleTextColor="#123412"
custom:titleTextSize="10sp"/>
</RelativeLayout>2.5 TopBarTest.java
package com.imooc.systemwidget;
public class TopBarTest extends Activity {
private TopBar mTopbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.topbar_test);
// 获得我们创建的topbar
mTopbar = (TopBar) findViewById(R.id.topBar);
// 为topbar注册监听事件，传入定义的接口
// 并以匿名类的方式实现接口内的方法
mTopbar.setOnTopbarClickListener(
new TopBar.topbarClickListener() {
@Override
public void rightClick() {
Toast.makeText(TopBarTest.this,
"right", Toast.LENGTH_SHORT)
.show();
}
@Override
public void leftClick() {
Toast.makeText(TopBarTest.this,
"left", Toast.LENGTH_SHORT)
.show();
}
});
// 控制topbar上组件的状态
mTopbar.setButtonVisable(0, true);
mTopbar.setButtonVisable(1, false);
}
}
时间： 2024-10-24 02:06:01