Android--Butter Knife

本文主要是介绍Android--Butter Knife，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

github:https://github.com/JakeWharton/butterknife;
使用指南：http://jakewharton.github.io/butterknife/

ButterKnife 优势：
1.强大的View绑定和Click事件处理功能
2.方便的处理Adapter里的ViewHolder绑定问题

使用心得：
1.Activity 中ButterKnife.bind(this);必须在setContentView();之后，且父类bind绑定后，子类不需要再bind；
2.Fragment ButterKnife.bind(this, rootView);
3.属性不能用private or static 修饰，否则会报错

一：配置：
app–build.gradle

apply plugin: 'com.neenbedankt.android-apt'
dependencies {
compile 'com.jakewharton:butterknife:8.0.1'
apt 'com.jakewharton:butterknife-compiler:8.0.1'
}

gradle–build.gradle

dependencies {classpath 'com.android.tools.build:gradle:2.1.0'
classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
}

二：使用：

text = (TextView) findViewById(R.id.text);
text.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {}
});

可以写成：

@BindView(R.id.text)
TextView text;
@OnClick({R.id.text})
void Click() {Toast.makeText(this, "text", Toast.LENGTH_LONG).show();
}

public class MainActivity extends AppCompatActivity {
@BindView(R.id.text)TextView text;@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
text = (TextView) findViewById(R.id.text);
text.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {}});
}@OnClick({R.id.text})
void Click() {Toast.makeText(this, "text", Toast.LENGTH_LONG).show();
}
}

目前是简单体验一下，接下来，我们讲解更多的使用方法：
1–Base:
ButterKnife.bind(this)需要与Activity绑定到一起，而绑定Activity 必须在setContentView之后：

public abstract class BaseActivity extends AppCompatActivity {
public abstract int getContentViewId();private Unbinder unbinder;@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(getContentViewId());
unbinder = ButterKnife.bind(this);
initViews(savedInstanceState);
}protected abstract void initViews(Bundle bundle);/*** 解除绑定*/
@Override
protected void onDestroy() {
super.onDestroy();
unbinder.unbind();
}
}

public abstract class BaseFragment extends Fragment {
public abstract int getContentViewId();protected Context context;protected View rootView;private Unbinder unbinder;@Nullable@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
rootView = inflater.inflate(getContentViewId(), container, false);
unbinder = ButterKnife.bind(this, rootView);this.context = getActivity();
initViews(savedInstanceState);return rootView;
}protected abstract void initViews(Bundle bundle);@Override
public void onDestroyView() {
super.onDestroyView();
unbinder.unbind();
}
}

2–View:

@BindView(R.id.text)
TextView text;@BindView(R.id.button)
Button button;

3–资源

@BindString(R.string.app_name)  
String appName;//sting  
@BindColor(R.color.red)  
int textColor;//颜色  
@BindDrawable(R.mipmap.ic_launcher)  
Drawable drawable;//drawble  
@Bind(R.id.imageview)  
ImageView mImageView;  
@Bind(R.id.checkbox)  
CheckBox mCheckBox;  
@BindDrawable(R.drawable.selector_image)  
Drawable selector;  

4–ViewHolder：
—-减少更多重复代码：

public class MyAdapter extends BaseAdapter {@Override public View getView(int position, View view, ViewGroup parent) {ViewHolder holder;if (view != null) {holder = (ViewHolder) view.getTag();} else {view = inflater.inflate(R.layout.whatever, parent, false);//此处为节省代码holder = new ViewHolder(view);view.setTag(holder);}holder.name.setText("John Doe");return view;}staticclassViewHolder{
@BindView(R.id.title) 
TextView name;
@BindView(R.id.job_title)
TextView jobTitle;
publicViewHolder(View view){ButterKnife.bind(this, view);
}
}

5–绑定View集合：

@BindViews ({R.id.button,R.id.button2,R.id.button3})
List<Button> button;

6–批量处理事件：
—-批量处理View事件

ButterKnife.apply(button);
ButterKnife.apply(button, ENABLED,false);
ButterKnife.apply(button, View.ALPHA, 0.0f);

—设置统一处理：

static final ButterKnife.Action<View> DISABLE = new ButterKnife.Action<View>() {
@Override
public void apply(View view, int index) {view.setEnabled(false);
}
};
static final ButterKnife.Setter<View, Boolean> ENABLED = new ButterKnife.Setter<View, Boolean>() {
@Override
public void set(View view, Boolean value, int index) {view.setEnabled(value);
}
};

7–View事件的监听：
–1：监听器参数可选

@OnClick({R.id.button})
void Click() {Toast.makeText(this, "text", Toast.LENGTH_LONG).show();
}

--2：

@OnClick({R.id.button})
void Click(View view) {
switch (view.getId()) {
case R.id.button:Toast.makeText(this, "text", Toast.LENGTH_LONG).show();break;
}}

–3：定义一个类型，自动转换：

@OnClick({R.id.button})
void Click(Button btn) {btn.setText("onClick");
Toast.makeText(this, "text", Toast.LENGTH_LONG).show();
}

–4：继承View，也可使用监听：
—-自定义View，可以不指定ID，绑定自己的监听

public class CommitButton extends Button {public CommitButton(Context context) {super(context);}public CommitButton(Context context, AttributeSet attrs) {super(context, attrs);}public CommitButton(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);}@OnClickvoid click(){}
}

三：空处理：
—-默认情况下，“绑定”和“监听”绑定都是必需的。如果不能找到目标视图，则将抛出异常。

@Nullable
@BindView(R.id.button)
Button button;
而针对事件监听处理：
@Optional
@OnClick(R.id.button)
void Click() {Toast.makeText(this, "text", Toast.LENGTH_LONG).show();
}

四：添加多回调方法的监听的使用方法，利用指定回调，实现想回调的方法
–1：listView:

@OnItemClick(value=R.id.listView)
void onItemSelected() {}@OnItemLongClick()
void onItemLongClick(ListView listView){}

–2:EditText

@BindView(R.id.edit)
EditText edit;

@OnTextChanged(value = R.id.edit, callback = OnTextChanged.Callback.BEFORE_TEXT_CHANGED)
void beforeTextChanged(CharSequence s, int start, int count, int after) {}
@OnTextChanged(value = R.id.edit, callback = OnTextChanged.Callback.TEXT_CHANGED)
void onTextChanged(CharSequence s, int start, int before, int count) {}
@OnTextChanged(value = R.id.edit, callback = OnTextChanged.Callback.AFTER_TEXT_CHANGED)
void afterTextChanged(Editable s) {}

以下是源码：可以看出，我们在正常使用某个方法的时候，系统都会提供和原生一样的参数供我们使用，所以，可以了解到我们在使用方法时，参数可以保持和原生方法参数一致并使用(其他控件方法也适用)：

@Target(METHOD)
@Retention(CLASS)
@ListenerClass(targetType = "android.widget.TextView",setter = "addTextChangedListener",type = "android.text.TextWatcher",callbacks = OnTextChanged.Callback.class
)
public @interface OnTextChanged {@IdRes int[] value() default { View.NO_ID };Callback callback() default Callback.TEXT_CHANGED;enum Callback {@ListenerMethod(name = "onTextChanged",parameters = {"java.lang.CharSequence","int","int","int"})TEXT_CHANGED,@ListenerMethod(name = "beforeTextChanged",parameters = {"java.lang.CharSequence","int","int","int"})BEFORE_TEXT_CHANGED,@ListenerMethod(name = "afterTextChanged",parameters = "android.text.Editable")AFTER_TEXT_CHANGED,}
}

五：在使用整体View,或者Dialog使用：符合使用场景：

View view = LayoutInflater.from(context).inflate(R.layout.thing, null);
TextView firstName = ButterKnife.findById(view, R.id.first_name);
TextView lastName = ButterKnife.findById(view, R.id.last_name);
ImageView photo = ButterKnife.findById(view, R.id.photo);

完结：

这篇关于Android--Butter Knife的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---