如何实现自定义选择状态的CustomView？ [英] How to implement a CustomView with custom selector states?

问题描述

我想创建一个 CustomView 显示图像。在点击视图应改变其状态。应该有三种状态（关，设置，NotSet，要）视图可以重新present。我想用的选择在XML中做到这一点。它并不necesseraliy需要是一个定制的选择器。我可以重复选择的三种状态（这并不重要，如果国家的名称不同的话）。

I want to create a CustomView that displays an image. On click the view should change its state. There should be three states (off, set, notset) the view can represent. I want to do this with a selector in XML. It does not necesseraliy need to be a custom selector. I could reuse three states of the selector (it does not matter if the names of the state are different then).

有没有实现这一目标的好方法？

Is there a good way to achieve this?

推荐答案

万一您的问题并没有解决自己呢。我做状态的改变与新实施的Andr​​oid 按钮。

Just in case your issue has not resolved itself yet. I do the changing of states with a new implementation of the Android Button.

的状态中的.xml通过的选择定义和设置。在这里，在 attrs.xml 文件中定义的三种状态：

The states are defined in .xml and set via a selector. Here the three states defined in the attrs.xml file:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="states">
        <attr name="state_on" format="boolean" />
        <attr name="state_off" format="boolean" />
        <attr name="state_notset" format="boolean" />
    </declare-styleable>
</resources>

和选择器（ statebutton_selector.xml ）在可绘制文件夹中： （我认为让一个特定的状态会自动禁用其他国家 - 的可绘制像STATE_ON只是png格式图片重新presenting各州）

And the selector (statebutton_selector.xml) inside the drawables folder: (I assume that enabling a specific state automatically disables the other states - the drawables like "state_on" are just .png images representing the individual states)

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res/com.example.statebuttontest">
<item
    app:state_on="true"
    app:state_off="false"
    app:state_notset="false"
    android:drawable="@drawable/state_on" />
<item
    app:state_on="false"
    app:state_off="true"
    app:state_notset="false"
    android:drawable="@drawable/state_off" />
<item
    app:state_on="false"
    app:state_off="false"
    app:state_notset="true" 
    android:drawable="@drawable/state_notset" />
</selector>

此外，要知道引用您正确的包名在选择XML文件，如你的清单文件中指出：

Also, be aware to reference your correct package name in the selector xml file, as stated in your Manifest file:

xmlns:app="http://schemas.android.com/apk/res/com.example.statebuttontest"

最后， StateButton 类扩展按钮。用一个简单的 OnClickListener 的状态改变。我也实现了一个 OnStateChangedListener 的比如可以通过包含该按钮，将被调用时的状态变化的活动来实现。

And finally, the StateButton class that extends Button. With a simple OnClickListener the state is changed. I also implemented an OnStateChangedListener that for example can be implemented by an Activity that contains the Button and will be called whenever the state changes.

状态本身就是 onCreateDrawableState（...）方法内完成被称为的变化自动每次按钮被点击。 extraspace + 1的意思，那会有drawableStates阵列内的一个附加状态。

The changing of the state itself is done inside the onCreateDrawableState(...) method that is called automatically every time the Button is clicked. "extraspace + 1" means, that there will be one additional state inside the drawableStates array.

public class StateButton extends Button implements OnClickListener {

    private static final int[] mStates = { R.attr.state_notset, R.attr.state_on, R.attr.state_off };
    private int mStateIndex = 0; // first state is "notset"

    private OnStateChangedListener mListener;

    public StateButton(Context context, AttributeSet attrs) {
        super(context, attrs);

        setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        changeState();
    }

    public void changeState() {
        mStateIndex = (mStateIndex+1) % mStates.length;

        // notify listener
        if(mListener != null) mListener.onStateChanged(mStates[mStateIndex]);
    }

    @Override
    protected int[] onCreateDrawableState(int extraSpace) {

        final int[] drawableState = super.onCreateDrawableState(extraSpace+1);

        int [] state = { mStates[mStateIndex] };

        mergeDrawableStates(drawableState, state);

        return drawableState;
    }

    public void setOnStateChangedListener(OnStateChangedListener l) {
        this.mListener = l;
    }
}

最后但并非最不重要的，设置选择为背景你的按钮：

<com.example.statebuttontest.StateButton
        android:id="@+id/stateButton1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:background="@drawable/statebutton_selector"
        android:text="" />

在活动的一个例子（与监听器）：

public class MainActivity extends Activity implements OnStateChangedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        StateButton s = (StateButton) findViewById(R.id.stateButton1);
        s.setOnStateChangedListener(this);
    }

    @Override
    public void onStateChanged(int state) {
        Log.i("Main", "State changed to: " + getResources().getResourceEntryName(state));
    }
}

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