在onSaveInstanceState中保存图像按钮的isSelected（）属性并将其恢复

Question

假设我有一个图像按钮，更改图像onClick()，因此isSelected()属性为true。如何在onSaveInstanceState()中保存此属性，以便以后可以在旋转手机时将其恢复？

Answer 1

首先，将isSelected()属性保存在onSaveInstanceState()

中

public final String STATE_SELECTED = "state_selected";

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    super.onSaveInstanceState(savedInstanceState);
    savedInstanceState.putBoolean(STATE_SELECTED, button.isSelected());
}

然后在onRestoreInstanceState()

中访问并使用此值

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    boolean selected = savedInstanceState.getBoolean(STATE_SELECTED);
    button.setSelected(selected);
    if (selected) // Do some stuff
    else //Do some other stuff
}

希望这有帮助！

编辑：在回复您的评论时，以下是按钮数组的执行方式：

public final String STATE_SELECTED = "state_selected";
public Button[] buttons; // This is populated elsewhere

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    super.onSaveInstanceState(savedInstanceState);
    boolean[] selected = new boolean[buttons.length];
    for (int i = 0; i < buttons.length; i++) selected[i] = buttons[i].isSelected();
    savedInstanceState.putBooleanArray(STATE_SELECTED, selected);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    boolean[] selected = savedInstanceState.getBooleanArray(STATE_SELECTED);
    for (int i = 0; i < buttons.length; i++) button[i].setSelected(selected[i]);
}