Question

有人知道是否可以使ImageView可检查。我尝试在我的项目中使用State-list drawable资源，我为ImageView检查状态定义图片，但没有属性可以使ImageView可检查，只能点击。

也许有人知道解决这个问题的方法吗？

Answer 1

使用此自定义ImageView实现（取自here）：

public class CheckableImageView extends ImageView implements Checkable {
    private boolean mChecked;

    private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };

    public CheckableImageView(final Context context, final AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public int[] onCreateDrawableState(final int extraSpace) {
        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
        if (isChecked())
            mergeDrawableStates(drawableState, CHECKED_STATE_SET);
        return drawableState;
    }

    @Override
    public void toggle() {
        setChecked(!mChecked);
    }

    @Override
    public boolean isChecked() {
        return mChecked;
    }

    @Override
    public void setChecked(final boolean checked) {
        if (mChecked == checked)
            return;
        mChecked = checked;
        refreshDrawableState();
    }
}

Answer 2

您可以将状态列表设置为可绘制的状态列表，而不是将ImageView设置为可选的复选框，以便自动翻转图像。

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checkable="true" android:drawable="@drawable/icon_pressed" /> <!-- pressed -->
    <item android:state_checked="true" android:drawable="@drawable/icon_focused" /> <!-- focused -->
    <item android:drawable="@drawable/icon_default" /> <!-- default -->
</selector>

Answer 3

我从Android开发人员的代码中实现OnClickListener以进行直接检查。

public class CheckableImageView extends ImageView implements Checkable, View.OnClickListener {
    private boolean mChecked;

    private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };

    public CheckableImageView(final Context context, final AttributeSet attrs) {
        super(context, attrs);

        setOnClickListener(this);
    }

    @Override
    public int[] onCreateDrawableState(final int extraSpace) {
        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
        if (isChecked())
            mergeDrawableStates(drawableState, CHECKED_STATE_SET);
        return drawableState;
    }

    @Override
    public void toggle() {
        setChecked(!mChecked);
    }

    @Override
    public boolean isChecked() {
        return mChecked;
    }

    @Override
    public void setChecked(final boolean checked) {
        if (mChecked == checked)
            return;
        mChecked = checked;
        refreshDrawableState();
    }

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

Answer 4

如果要在单击ImageView时更改检查状态，请将“extend ImageView”更改为CompoundButton。

public class CheckableImageView extends CompoundButton {

    public CheckableImageView(Context context) {
        super(context);
    }

    public CheckableImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    private static final int[] CheckedStateSet = {android.R.attr.state_checked};

    public void setChecked(boolean b) {
        boolean oldState = isChecked();
        super.setChecked(b);
        if (b != oldState) {
            refreshDrawableState();
        }
    }

    @Override
    public int[] onCreateDrawableState(int extraSpace) {
        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
        if (isChecked()) {
            mergeDrawableStates(drawableState, CheckedStateSet);
        }
        return drawableState;
    }

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();
        invalidate();
    }

}

Answer 5

这是我在我的应用中使用的

public class MainActivity extends Activity implements OnClickListener {

private boolean paused = false;  

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub

        switch (v.getId()) {

            case R.id.imageview_pause:

                paused = !paused;

                if (paused) {

                    btn_pause.setBackgroundResource(R.drawable.pause_key_pressed);

                }else{

                    btn_pause.setBackgroundResource(R.drawable.pause_key);
                }

                break;
        }
}
}

可检查的ImageView

5 个答案: