如何以编程方式设置一个自定义标题栏的背景颜色渐变？ [英] How do I programmatically set the background color gradient on a Custom Title Bar?

问题描述

有很多教程在那里和问题上，以便实现自定义标题栏。然而，在我的自定义标题栏我有一个自定义渐变为背景，我想知道如何动态地在我的code设置。

There are many tutorials out there and questions on SO that implement custom title bars. However, in my custom title bar I have a custom gradient for the background and I would like to know how to set it dynamically in my code.

下面是我的自定义标题栏被调用：

Here is where my custom title bar gets called:

requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.foo_layout);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title_bar); 

这是我的 custom_title_bar ：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@layout/custom_title_bar_background_colors">
<ImageView   
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:src="@drawable/title_bar_logo"
              android:gravity="center_horizontal"
              android:paddingTop="0dip"/>

</LinearLayout>

正如你所看到的，对线性布局的背景是这家伙定义的：

As you can see, the background on the linear layout is defined by this guy:

<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient 
    android:startColor="#616261" 
    android:endColor="#131313"
    android:angle="270"
 />
<corners android:radius="0dp" />

我想要做的是动态设置的渐变颜色在我的code。我不希望到c他们难以$ C $在我的XML文件，就像他们现在是。

What I would like to do is set those gradient colors dynamically in my code. I do not want to hard code them in my XML file like they currently are.

我向所有人开放的想法，如果你有设置背景渐变的更好的方法。

I am open to all ideas if you have a better way of setting a background gradient.

感谢你在前进！

推荐答案

要做到这一点在code，创建GradientDrawable。
唯一的机会来设置角度和色彩是在构造函数中。 如果你想改变颜色或角度，只要创建一个新GradientDrawable，并将其设置为背景

To do this in code, you create a GradientDrawable.
The only chance to set the angle and color is in the constructor. If you want to change the color or angle, just create a new GradientDrawable and set it as the background

    View layout = findViewById(R.id.mainlayout);

    GradientDrawable gd = new GradientDrawable(
            GradientDrawable.Orientation.TOP_BOTTOM,
            new int[] {0xFF616261,0xFF131313});
    gd.setCornerRadius(0f);

    layout.setBackgroundDrawable(gd);

对于这项工作，我添加了一个ID为你的主要的LinearLayout如下：

For this to work, I added an id to your main LinearLayout as follows

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mainlayout"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
<ImageView   
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:src="@drawable/title_bar_logo"
              android:gravity="center_horizontal"
              android:paddingTop="0dip"/>

</LinearLayout>

和使用这个作为一个自定义标题栏

And to use this as for a custom title bar

    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,R.layout.custom_title_bar);
    View title = getWindow().findViewById(R.id.mainlayout);
    title.setBackgroundDrawable(gd);

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