问题
I am Trying to Generate Random Colors and set the Random color as background of Text View Just Like in GMail app. The Text view is Having a circular background initially set in xml which i have done using shape. I have done some research and used some code available on internet but the changes are not reflecting in my app.
Below is my Recycler View Adapter Class:
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.Items> {
ArrayList<GmailDataHolder> data;
Context context;
public RecyclerViewAdapter(ArrayList<GmailDataHolder> data, Context context) {
this.data = data;
this.context = context;
}
@Override
public RecyclerViewAdapter.Items onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(context).inflate(R.layout.gmail_layout_row, parent, false);
Items i = new Items(v);
return i;
}
@Override
public void onBindViewHolder(final RecyclerViewAdapter.Items holder, int position) {
//Generating Random Color
int randomAndroidColor = holder.androidColors[new Random().nextInt(holder.androidColors.length)];
Drawable background = holder.circleTv.getBackground();
if (background instanceof ShapeDrawable) {
((ShapeDrawable)background).getPaint().setColor(randomAndroidColor);
} else if (background instanceof GradientDrawable) {
((GradientDrawable)background).setColor(randomAndroidColor);
} else if (background instanceof ColorDrawable) {
((ColorDrawable)background).setColor(randomAndroidColor);
}
holder.line1.setText(data.get(position).getLine1());
holder.line2.setText(data.get(position).getLine2() + "...");
holder.line3.setText(data.get(position).getLine3() + "...");
holder.time.setText(data.get(position).getTime());
//get Star Image State from MySql DB
MyFunctions.getStarState(data, holder, position);
holder.circleTv.setText(String.valueOf(data.get(position).getLine1().charAt(0)).toUpperCase());
//Changing Star Image on Click
MyFunctions.starClickListener(holder);
}
@Override
public int getItemCount() {
return data.size();
}
public class Items extends RecyclerView.ViewHolder {
TextView circleTv, line1, line2, line3, time;
int[] androidColors;
public ImageView star;
public Items(View itemView) {
super(itemView);
//Loading Color from resources
androidColors = itemView.getResources().getIntArray(R.array.androidcolors);
circleTv = (TextView) itemView.findViewById(R.id.tv_circle);
line1 = (TextView) itemView.findViewById(R.id.tv_line1);
line2 = (TextView) itemView.findViewById(R.id.tv_line2);
line3 = (TextView) itemView.findViewById(R.id.tv_line3);
time = (TextView) itemView.findViewById(R.id.tv_time);
star = (ImageView) itemView.findViewById(R.id.img_star);
}
}
Colors.xml File:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#3F51B5</color>
<color name="colorPrimaryDark">#303F9F</color>
<color name="colorAccent">#dc4538</color>
<color name="colorFacebook">#374dae</color>
<color name="colorCenterFb">#d5617ae6</color>
<color name="colorStartGoogle">#d8dd4c3a</color>
<color name="colorEndGoogle">#dd4c3a</color>
<color name="colorEndLinkedIn">#1887b0</color>
<color name="colorStartLinkedIn">#e31887b0</color>
<color name="colorStrokeLinkedIn">#ec106584</color>
<color name="colorStrokeGoogle">#b73e2e</color>
<color name="colorStrokeFacebook">#e2263a91</color>
<color name="status">#ba3223</color>
<item name="blue" type="color">#FF33B5E5</item>
<item name="purple" type="color">#FFAA66CC</item>
<item name="green" type="color">#FF99CC00</item>
<item name="orange" type="color">#FFFFBB33</item>
<item name="red" type="color">#FFFF4444</item>
<item name="darkblue" type="color">#FF0099CC</item>
<item name="darkpurple" type="color">#FF9933CC</item>
<item name="darkgreen" type="color">#FF669900</item>
<item name="darkorange" type="color">#FFFF8800</item>
<item name="darkred" type="color">#FFCC0000</item>
<integer-array name="androidcolors">
<item>@color/blue</item>
<item>@color/purple</item>
<item>@color/green</item>
<item>@color/orange</item>
<item>@color/red</item>
<item>@color/darkblue</item>
<item>@color/darkpurple</item>
<item>@color/darkgreen</item>
<item>@color/darkorange</item>
<item>@color/darkred</item>
</integer-array>
</resources>
Initially The TextView is having the following Background declared in xml:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval">
<solid
android:color="#48b3ff"/>
</shape>
回答1:
Random r = new Random();
int red=r.nextInt(255 - 0 + 1)+0;
int green=r.nextInt(255 - 0 + 1)+0;
int blue=r.nextInt(255 - 0 + 1)+0;
GradientDrawable draw = new GradientDrawable();
draw.setShape(GradientDrawable.OVAL);
draw.setColor(Color.rgb(red,green,blue));
mTextView.setBackground(draw);
回答2:
If you needs to use your own/required colors, just use below code
List<String> colors;
colors=new ArrayList<String>();
colors.add("#5E97F6");
colors.add("#9CCC65");
colors.add("#FF8A65");
colors.add("#9E9E9E");
colors.add("#9FA8DA");
colors.add("#90A4AE");
colors.add("#AED581");
colors.add("#F6BF26");
colors.add("#FFA726");
colors.add("#4DD0E1");
colors.add("#BA68C8");
colors.add("#A1887F");
// all colors used by gmail application :) may be,
// genrating random num from 0 to 11 because you can add more or less
Random r = new Random();
int i1 = r.nextInt(11- 0) + 0;
//genrating shape with colors
GradientDrawable draw = new GradientDrawable();
draw.setShape(GradientDrawable.OVAL);
draw.setColor(Color.parseColor(colors.get(i1)))
// assigning to textview
contact_name_circle.setBackground(draw); //textview
回答3:
If you want to generate random (any) color you can just doColor.rgb(Math.random()*255, Math.random()*255, Math.random()*255)
If you want to pick color from your list i would sugest leaving that xml file and making the list in java of all the colors you want and then just simply using randomly picked color from that array.
回答4:
// google's material design colours from , 254 colors
// http://www.google.com/design/spec/style/color.html#color-ui-color-palette
public String[] mColors = {
"FFEBEE", "FFCDD2", "EF9A9A", "E57373", "EF5350", "F44336", "E53935", //reds
"D32F2F", "C62828", "B71C1C", "FF8A80", "FF5252", "FF1744", "D50000",
"FCE4EC", "F8BBD0", "F48FB1", "F06292", "EC407A", "E91E63", "D81B60", //pinks
"C2185B", "AD1457", "880E4F", "FF80AB", "FF4081", "F50057", "C51162",
"F3E5F5", "E1BEE7", "CE93D8", "BA68C8", "AB47BC", "9C27B0", "8E24AA", //purples
"7B1FA2", "6A1B9A", "4A148C", "EA80FC", "E040FB", "D500F9", "AA00FF",
"EDE7F6", "D1C4E9", "B39DDB", "9575CD", "7E57C2", "673AB7", "5E35B1", //deep purples
"512DA8", "4527A0", "311B92", "B388FF", "7C4DFF", "651FFF", "6200EA",
"E8EAF6", "C5CAE9", "9FA8DA", "7986CB", "5C6BC0", "3F51B5", "3949AB", //indigo
"303F9F", "283593", "1A237E", "8C9EFF", "536DFE", "3D5AFE", "304FFE",
"E3F2FD", "BBDEFB", "90CAF9", "64B5F6", "42A5F5", "2196F3", "1E88E5", //blue
"1976D2", "1565C0", "0D47A1", "82B1FF", "448AFF", "2979FF", "2962FF",
"E1F5FE", "B3E5FC", "81D4fA", "4fC3F7", "29B6FC", "03A9F4", "039BE5", //light blue
"0288D1", "0277BD", "01579B", "80D8FF", "40C4FF", "00B0FF", "0091EA",
"E0F7FA", "B2EBF2", "80DEEA", "4DD0E1", "26C6DA", "00BCD4", "00ACC1", //cyan
"0097A7", "00838F", "006064", "84FFFF", "18FFFF", "00E5FF", "00B8D4",
"E0F2F1", "B2DFDB", "80CBC4", "4DB6AC", "26A69A", "009688", "00897B", //teal
"00796B", "00695C", "004D40", "A7FFEB", "64FFDA", "1DE9B6", "00BFA5",
"E8F5E9", "C8E6C9", "A5D6A7", "81C784", "66BB6A", "4CAF50", "43A047", //green
"388E3C", "2E7D32", "1B5E20", "B9F6CA", "69F0AE", "00E676", "00C853",
"F1F8E9", "DCEDC8", "C5E1A5", "AED581", "9CCC65", "8BC34A", "7CB342", //light green
"689F38", "558B2F", "33691E", "CCFF90", "B2FF59", "76FF03", "64DD17",
"F9FBE7", "F0F4C3", "E6EE9C", "DCE775", "D4E157", "CDDC39", "C0CA33", //lime
"A4B42B", "9E9D24", "827717", "F4FF81", "EEFF41", "C6FF00", "AEEA00",
"FFFDE7", "FFF9C4", "FFF590", "FFF176", "FFEE58", "FFEB3B", "FDD835", //yellow
"FBC02D", "F9A825", "F57F17", "FFFF82", "FFFF00", "FFEA00", "FFD600",
"FFF8E1", "FFECB3", "FFE082", "FFD54F", "FFCA28", "FFC107", "FFB300", //amber
"FFA000", "FF8F00", "FF6F00", "FFE57F", "FFD740", "FFC400", "FFAB00",
"FFF3E0", "FFE0B2", "FFCC80", "FFB74D", "FFA726", "FF9800", "FB8C00", //orange
"F57C00", "EF6C00", "E65100", "FFD180", "FFAB40", "FF9100", "FF6D00",
"FBE9A7", "FFCCBC", "FFAB91", "FF8A65", "FF7043", "FF5722", "F4511E", //deep orange
"E64A19", "D84315", "BF360C", "FF9E80", "FF6E40", "FF3D00", "DD2600",
"EFEBE9", "D7CCC8", "BCAAA4", "A1887F", "8D6E63", "795548", "6D4C41", //brown
"5D4037", "4E342E", "3E2723",
"FAFAFA", "F5F5F5", "EEEEEE", "E0E0E0", "BDBDBD", "9E9E9E", "757575", //grey
"616161", "424242", "212121",
"ECEFF1", "CFD8DC", "B0BBC5", "90A4AE", "78909C", "607D8B", "546E7A", //blue grey
"455A64", "37474F", "263238"
};
These are the material design colors.take a random color from it.
// generate a random number
int i = new Random().nextInt(254);
it will generate a random number from 0 to 254
GradientDrawable shape = new GradientDrawable();
shape.setShape(GradientDrawable.OVAL);
shape.setColor(Color.parseColor ("#"+mColors[new Random().nextInt(254)]));
mTextView..setBackground(shape);
it will choose a random color from the list and set as textview background color
回答5:
In your onBindViewHolder you can do the following:
int remainder = getAdapterPosition() % colorsArray.size();
mView.setCardBackgroundColor(Color.parseColor(colorsArray.get(remainder)));
In this way, each RecyclerView item will show the same color on scrolling and also each time when user will see this list.
回答6:
This is what you want
on BindViewHolder Method
Random r = new Random();
int red=r.nextInt(255 - 0 + 1)+0;
int green=r.nextInt(255 - 0 + 1)+0;
int blue=r.nextInt(255 - 0 + 1)+0;
GradientDrawable draw = new GradientDrawable();
draw.setShape(GradientDrawable.RECTANGLE);
draw.setColor(Color.rgb(red,green,blue));
holder.viewInside.setBackground(draw);
ps- view inside is the name of the view.
If you want the exact type of Gmail view then you can use this tiny library which will give you the exact thing you want.
https://github.com/amulyakhare/TextDrawable
来源：https://stackoverflow.com/questions/41084162/generate-and-set-random-colors-on-text-view-background-within-recycler-view-in-a