[Android]代码实现ColorStateList及StateListDrawable

点：灵活，减少xml的编写。应用在TextView的文字时，亦避免使用了OnTouchListener。

用途：动态设置TextView、Button、ImageView等组件在不同状态下的背景/前景显示效果。

参考：

[AndroidOpenSource]\frameworks\base\core\java\android\view\view.xml

[AndroidOpenSource]\frameworks\base\core\res\res\values\public.xml

效果图如下：



代码如下：

package lab.sodino.statelist;

import android.app.Activity;
import android.content.Context;
import android.content.res.ColorStateList;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.StateListDrawable;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

/**
 * 对TextView设置ColorStateList使其在Normal、Pressed、Focused、Unable四种状态下显示不同的颜色。<br/>
 * StateListDrawable可直接使用图片应用在相似场合。
 */
public class ActColorStateList extends Activity implements OnClickListener {
	private TextView txtShow;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		txtShow = (TextView) findViewById(R.id.txtShow);
		txtShow.setText("Sodino\nNormal:0xffffffff\nPressed:0xffffff00\nFocused:0xff0000ff\nUnable:0xffff0000");
		txtShow.setTextColor(createColorStateList(0xffffffff, 0xffffff00, 0xff0000ff, 0xffff0000));
		txtShow.setOnClickListener(this);
	}

	/** 对TextView设置不同状态时其文字颜色。 */
	private ColorStateList createColorStateList(int normal, int pressed, int focused, int unable) {
		int[] colors = new int[] { pressed, focused, normal, focused, unable, normal };
		int[][] states = new int[6][];
		states[0] = new int[] { android.R.attr.state_pressed, android.R.attr.state_enabled };
		states[1] = new int[] { android.R.attr.state_enabled, android.R.attr.state_focused };
		states[2] = new int[] { android.R.attr.state_enabled };
		states[3] = new int[] { android.R.attr.state_focused };
		states[4] = new int[] { android.R.attr.state_window_focused };
		states[5] = new int[] {};
		ColorStateList colorList = new ColorStateList(states, colors);
		return colorList;
	}

	/** 设置Selector。 */
	public static StateListDrawable newSelector(Context context, int idNormal, int idPressed, int idFocused,
			int idUnable) {
		StateListDrawable bg = new StateListDrawable();
		Drawable normal = idNormal == -1 ? null : context.getResources().getDrawable(idNormal);
		Drawable pressed = idPressed == -1 ? null : context.getResources().getDrawable(idPressed);
		Drawable focused = idFocused == -1 ? null : context.getResources().getDrawable(idFocused);
		Drawable unable = idUnable == -1 ? null : context.getResources().getDrawable(idUnable);
		// View.PRESSED_ENABLED_STATE_SET
		bg.addState(new int[] { android.R.attr.state_pressed, android.R.attr.state_enabled }, pressed);
		// View.ENABLED_FOCUSED_STATE_SET
		bg.addState(new int[] { android.R.attr.state_enabled, android.R.attr.state_focused }, focused);
		// View.ENABLED_STATE_SET
		bg.addState(new int[] { android.R.attr.state_enabled }, normal);
		// View.FOCUSED_STATE_SET
		bg.addState(new int[] { android.R.attr.state_focused }, focused);
		// View.WINDOW_FOCUSED_STATE_SET
		bg.addState(new int[] { android.R.attr.state_window_focused }, unable);
		// View.EMPTY_STATE_SET
		bg.addState(new int[] {}, normal);
		return bg;
	}

	@Override
	public void onClick(View v) {
		if (v == txtShow) {
			txtShow.setEnabled(false);
		}
	}
}