Builder模式及其在Android中的使用
16lz
2021-01-23
Builder模式及其在Android中的使用
本篇blog主要介绍builder模式的概念、demo 以及在Android中的运用等等：
- 概念
- 实验demo
- Android运用
- 总结
Builder概念
作为一个开发人员，不论你是初入职场的菜鸟，还是这个领域的专家，在面对复杂多变的组织结构和频繁修改需求时，一个好的设计就显得尤为重要。如果一个类反复修改，我们使用传统的方式，会写很多的构造参数，如果修改的话，涉及到的都要修改，此时会很麻烦，不利于维护和扩展。此时，我们需要一种灵活多变的模式来应对多变的需求，builder模式就是其中一种。builder是对于我们的需求来说，主要架构和脉络不变，只是会改变它的细节(增加或减少），让开发者快速维护的一种模式。
那么写个demo吧。
思路 （模型测试）：
写类 ：目的就是数据传入，并能分别获取。
传统写法：
Bean:
public class DesignBean implements Serializable { private static final long serialVersionUID = 2035522819932441426L; //三个参数 三个方法方便DesignBean获取各个参数 private String builder_name; private String builder_age; private String builder_score; public String getBuilder_name() { return builder_name; } public String getBuilder_age() { return builder_age; } public String getBuilder_score() { return builder_score; } //传参函数 public DesignBean(String builder_name, String builder_age, String builder_score) { this.builder_name = builder_name; this.builder_age = builder_age; this.builder_score = builder_score; } //检验数据是否显示正确toString() public String toString() { return "姓名: " + builder_name + "，年龄: " + builder_age + "，成绩: " + builder_score; } }测试类：
public class MainActivity extends AppCompatActivity { TextView show; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); show = findViewById(R.id.show); show.setText(new DesignBean("zhangsan","18","80").toString()); }}传参看上去有点乱，我们不知参数含义，不够明确。我们把传参这块交给Builder去管理。
改进：
Bean:
/** * 功能：测试Bean */public class DesignBean implements Serializable { private static final long serialVersionUID = 2035522819932441426L; //三个参数 三个方法方便DesignBean获取各个参数 private String builder_name; private String builder_age; private String builder_score; public String getBuilder_name() { return builder_name; } public String getBuilder_age() { return builder_age; } public String getBuilder_score() { return builder_score; } //给Builder提供数据传递的方法 public DesignBean(String builder_name, String builder_age, String builder_score) { this.builder_name = builder_name; this.builder_age = builder_age; this.builder_score = builder_score; } public static class Builder { private String builder_name; private String builder_age; private String builder_score; //链式结构，开放三个参数 三个方法归Builder调用 public Builder addName(String name) { this.builder_name = name; return this; } public Builder addAge(String age) { this.builder_age = age; return this; } public Builder addScore(String score) { this.builder_score = score; return this; } //把Builder获取的数据返给DesignBean，达到目的 public DesignBean create() { return new DesignBean(builder_name, builder_age, builder_score); } } //检验数据是否显示正确toString() public String toString() { return "姓名: " + builder_name + "，年龄: " + builder_age + "，成绩: " + builder_score; }}测试：
public class MainActivity extends AppCompatActivity { TextView show; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); show = findViewById(R.id.show); DesignBean designBean = new DesignBean.Builder().addName("zhangsan").addAge("18").addScore("80").create(); show.setText("一条数据展示>>>\n"+designBean.toString()+"\n--------------------\n详细展示>>>\n姓名:"+designBean.getBuilder_name()+"\n年龄:"+designBean.getBuilder_age()+"\n成绩:"+designBean.getBuilder_score()); }}结果：
这种方式下，我们可以清楚每个参数含义。
Android 中可以用来写dialog：
public class BarOrderDialog extends Dialog { public BarOrderDialog(Context context) { super(context, R.style.commondialogstyle); } public static class Builder { private Context context; private OnChangeListener onChangeListener; private TextView orderbyname01, orderbyname02; private String name01,name02; public interface OnChangeListener { void orderbyname01(); void orderbyname02(); } public Builder setActionName01(String name01){ this.name01 = name01; return this; } public Builder setActionName02(String name02){ this.name02 = name02; return this; } public Builder(Context context) { this.context = context; } public Builder setOnClickListener(OnChangeListener onChangeListener) { this.onChangeListener = onChangeListener; return this; } public BarOrderDialog create() { final BarOrderDialog tiebaDialog = new BarOrderDialog(context); View view = LayoutInflater.from(context).inflate(R.layout.dialog_bar_order, null); orderbyname01 = (TextView) view.findViewById(R.id.orderbyname01); orderbyname02 = (TextView) view.findViewById(R.id.orderbyname02); orderbyname01.setText(name01); orderbyname02.setText(name02); orderbyname01.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { onChangeListener.orderbyname01(); } }); orderbyname02.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { onChangeListener.orderbyname02(); } }); Window win = tiebaDialog.getWindow(); win.getDecorView().setPadding(0, 0, 0, 0); WindowManager.LayoutParams lp = win.getAttributes(); //宽度可从开屏页获取 DisplayMetrics d = context.getResources().getDisplayMetrics(); // 获取屏幕宽、高用 lp.width = (int) (d.widthPixels * 0.7); //0.8*宽 lp.height = WindowManager.LayoutParams.WRAP_CONTENT; win.setAttributes(lp); win.setGravity(Gravity.CENTER); tiebaDialog.setContentView(view); tiebaDialog.setCanceledOnTouchOutside(true); return tiebaDialog; } }}使用时：
if (barOrderDialog == null) { barOrderDialog = new BarOrderDialog.Builder(TieBaActivity.this).setActionName01("查看方式01").setActionName02("查看方式02").setOnClickListener(new BarOrderDialog.Builder.OnChangeListener() { @Override public void orderbyname01() { // order_text.setText("查看方式01"); // order_text_float.setText("查看方式01"); barOrderDialog.dismiss(); } @Override public void orderbyname02() { // order_text.setText("查看方式02"); // order_text_float.setText("查看方式02"); barOrderDialog.dismiss(); } }).create(); }更多相关文章
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