将ImageView设置为PaintDrawable - Android

Question

我想将ImageView设置为SweepGradient。

这里是我的尝试：

protected void onCreate(@Nullable Bundle savedInstanceState) { 

    ImageView colorPicker = findViewById(R.id.color_picker); 
    colorPicker.setImageDrawable(CreateColorPickerDrawable()); 

} 

private PaintDrawable CreateColorPickerDrawable() 
{ 
    int[] colors = {0xFFFF0000, 0xFF00FF00, 0xFF0000FF}; 
    PaintDrawable paintDrawable = new PaintDrawable(); 

    paintDrawable.setCornerRadius(getResources().getDimension(R.dimen.corner_radius)); 

    SweepGradient sweepGradient = new SweepGradient(50, 50, colors, null); 
    paintDrawable.getPaint().setShader(sweepGradient); 

    return paintDrawable; 
} 

但似乎没有梯度。

我也看到了这一点：Imageview set color filter to gradient

但我想我们有了是比简单的解决方案（加上它需要一个位图src和我只是想我的ImageView为矩形W /圆角角落[这可以很容易地做到/ PaintDrawable]）。

如果任何人有任何指导/建议，将不胜感激！泰！

Answer 1

我被一个DERP。我只需将ImageView切换到普通视图，然后我就可以将背景drawable替换为我的paintDrawable。

protected void onCreate(@Nullable Bundle savedInstanceState) { 

View colorPicker = findViewById(R.id.color_picker); 
colorPicker.setBackground(CreateColorPickerDrawable()); 

} 

private PaintDrawable CreateColorPickerDrawable() { 
int[] colors = {0xFFFF0000, 0xFF00FF00, 0xFF0000FF}; 
PaintDrawable paintDrawable = new PaintDrawable(); 

paintDrawable.setCornerRadius(getResources().getDimension(R.dimen.corner_radius)); 

SweepGradient sweepGradient = new SweepGradient(50, 50, colors, null); 
paintDrawable.getPaint().setShader(sweepGradient); 

return paintDrawable; 
} 

Answer 2

如果您需要静态解决方案，则可以使用可绘制的XML文件。

XML（gradient_1.xml）

<?xml version="1.0" encoding="utf-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
    <gradient 
     android:startColor="#aa0000" 
     android:centerColor="#00aa00" 
     android:endColor="#0000aa" 
     android:angle="270"/> 
    <corners android:radius="0dp" /> 
</shape> 

的Java

ImageView imageView = (ImageView) findViewById(R.id.imageViewGradient); 
imageView.setImageResource(R.drawable.gradient_1);