Android学习笔记-自定义view保存状态

android在屏幕切换的时候会对view进行重新绘制，如果没有保存状态的话，之前的输入信息就没有了，对于android自身的控件都有保存状态和回复状态的方法，不过android只保存了在布局文件中有id的控件的状态。

对于自定义的view如果想要保存状态的话需要重写父类的onRestoreInstanceState和onSaveInstanceState方法

下面是我写的一个togglebutton的demo只保存了button的开关状态

//恢复状态
@Override
protected void onRestoreInstanceState(Parcelable state) {
if(!(state instanceof SavedState)) {
super.onRestoreInstanceState(state);
return;
}
SavedState savedState=(SavedState)state;
super.onRestoreInstanceState(savedState.getSuperState());
this.status=savedState.status;
}

//保存状态
@Override
protected Parcelable onSaveInstanceState() {
Parcelable superState=super.onSaveInstanceState();
SavedState savedState=new SavedState(superState);
savedState.status=this.status;
return savedState;

}

public static class SavedState extends BaseSavedState {
public   boolean status;

public SavedState(Parcelable superState) {
super(superState);
}

@Override
public int describeContents() {
return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest,flags);
dest.writeByte(this.status ? (byte) 1 : (byte) 0);
}

private SavedState(Parcel in) {
super(in);
this.status = in.readByte() != 0;
}

public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
@Override
public SavedState createFromParcel(Parcel source) {
return new SavedState(source);
}

@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}

最后附上网上看到的view状态保存的流程