基于Android(安卓)DataBinding的InverseBindingMethod改进SeekBar双向绑定（正向/反向）数据绑定

基于Android DataBinding的InverseBindingMethod改进SeekBar双向绑定（正向/反向）数据绑定

在前文《使用Android BindingAdapter与InverseBindingAdapter实现SeekBar双向（正向/反向）数据绑定》（链接：http://blog.csdn.net/zhangphil/article/details/77839555 ）基础上，用InverseBindingMethod改进双向绑定实现方案。

老规矩，先建立数据模型，PhilProgress.java：

package zhangphil.test;import android.databinding.BaseObservable;import android.databinding.ObservableInt;/** * Created by Phil on 2017/9/4. */public class PhilProgress extends BaseObservable {    public ObservableInt porgress = new ObservableInt();}

重写SeekBar，PhilSeekBar.java：

package zhangphil.test;import android.content.Context;import android.databinding.InverseBindingListener;import android.databinding.InverseBindingMethod;import android.databinding.InverseBindingMethods;import android.util.AttributeSet;import android.util.Log;import android.widget.SeekBar;/** * Created by Phil on 2017/9/4. */@InverseBindingMethods({@InverseBindingMethod(type = PhilSeekBar.class, attribute = "progress", event = "progressAttrChanged")})public class PhilSeekBar extends SeekBar {    private String TAG = "调试输出";    private int progress = 0;    private InverseBindingListener mInverseBindingListener;    public PhilSeekBar(Context context, AttributeSet attrs) {        super(context, attrs);        this.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {            @Override            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {                progress = i;                //触发反向数据的传递                if (mInverseBindingListener != null) {                    mInverseBindingListener.onChange();                }            }            @Override            public void onStartTrackingTouch(SeekBar seekBar) {            }            @Override            public void onStopTrackingTouch(SeekBar seekBar) {            }        });    }    public void setProgress(int p) {        Log.d(TAG, "setProgress:" + p);        if (progress != p) {            progress = p;            //这一句代码可以解决初始化阶段进度条显示的值正确，但没有及时更新UI的问题。            //super.setProgress(progress);        }    }    public int getProgress() {        Log.d(TAG, "getProgress:" + progress);        return progress;    }    public void setProgressAttrChanged(InverseBindingListener inverseBindingListener) {        if (inverseBindingListener != null) {            mInverseBindingListener = inverseBindingListener;        }    }}

写布局activity_main.xml使用PhilSeekBar:

<?xml version="1.0" encoding="utf-8"?>

测试的MainActivity.java:

package zhangphil.test;import android.app.Activity;import android.databinding.DataBindingUtil;import android.os.Bundle;import zhangphil.test.databinding.ActivityMainBinding;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);        final PhilProgress progress = new PhilProgress();        binding.setProgress(progress);        //设置一个初始值作为演示 数据 -> View        //这是最常见的进度设置。        progress.porgress.set(21);    }}

代码初始运行结果：

注意到虽然进度条显示到了21，但是却没有彩色着色，在PhilSeekBar的setProgress方法里面，启用super.setProgress可以解决这个问题。

手指拖动后的结果显示：

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