Window Feature自定标题栏

Android允许对手机屏幕的特征进行客户化，例如，客户化标题栏。如果我们想要对某一特征进行客户化，首先就要通过Window.requestFeature (int featureId) 方法进行申请。一旦申请了就不能去掉这个特征了。



Android事先为可能被客户化的特征定义了常量。
int DEFAULT_FEATURES The default features enabled
int FEATURE_CONTEXT_MENU Flag for the context menu.
int FEATURE_CUSTOM_TITLE Flag for custom title.
int FEATURE_INDETERMINATE_PROGRESS Flag for indeterminate progress
int FEATURE_LEFT_ICON Flag for having an icon on the left side of the title bar
int FEATURE_NO_TITLE Flag for the "no title" feature, turning off the title at the top of the screen.
int FEATURE_OPTIONS_PANEL Flag for the "options panel" feature.
int FEATURE_PROGRESS Flag for the progress indicator feature
int FEATURE_RIGHT_ICON Flag for having an icon on the right side of the title bar

下面以API Demo中Custom Title为例加以说明。

1. 首先创建客户化的title。

Xml代码
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/screen"
android:layout_width="match_parent" android:layout_height="match_parent"
android:orientation="vertical">
<TextView android:id="@+id/left_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:text="@string/custom_title_left" />
<TextView android:id="@+id/right_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="@string/custom_title_right" />
</RelativeLayout>

2. 在CustomTitle.java中将客户化的title应用到activity中。
Java代码
package com.example.android.apis.app;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.example.android.apis.R;

public class CustomTitle extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.custom_title);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title_1);

final TextView leftText = (TextView) findViewById(R.id.left_text);
final TextView rightText = (TextView) findViewById(R.id.right_text);
final EditText leftTextEdit = (EditText) findViewById(R.id.left_text_edit);
final EditText rightTextEdit = (EditText) findViewById(R.id.right_text_edit);
Button leftButton = (Button) findViewById(R.id.left_text_button);
Button rightButton = (Button) findViewById(R.id.right_text_button);

leftButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
leftText.setText(leftTextEdit.getText());
}
});
rightButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
rightText.setText(rightTextEdit.getText());
}
});
}
}

先在setContentView之前调用requestWindowFeature(Window.FEATURE_CUSTOM_TITLE)，申请对标题进行客户化。然后调用getWindow().setFeatureInt将新的title应用到activity上。



客户化window feature时需要注意：

1. 要在setContentView之前调用requestFeature。由于requestWindowFeature = getWindow().requestFeature，所以调用requestWindowFeature 也可。

2. 不能将其他title相关feature与FEATURE_CUSTOM_TITLE一起使用。